Add unauthenticated mode demo for coreSNTP library for time synchronization (#621)

Add the FreeRTOS/coreSNTP library as a submodule (along with manifest.yaml file update) and add a demo project to showcase use of the coreSNTP library for having a SNTP client daemon in the system for periodically synchronizing system time with the internet to maintain Coordinated Univeral Time (UTC) in a device. This demo maintains UTC time of system in RAM, thereby, representing systems without a Real-Time Clock (RTC) module in the device.

Note: This demo shows use of coreSNTP library for SNTP communication with NTP/SNTP time servers in non-authenticated mode (i.e. without any security mechanism payload beyond the standard 48 bytes of NTP packet exchange between client-server).

16 files changed, 2641 insertions, 1 deletions

diff --git a/.gitmodules b/.gitmodules
index 77ca17f8f..27be47e25 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -49,3 +49,6 @@
 [submodule "FreeRTOS-Plus/Source/AWS/ota"]
 	path = FreeRTOS-Plus/Source/AWS/ota
 	url = https://github.com/aws/ota-for-aws-iot-embedded-sdk.git
+[submodule "FreeRTOS-Plus/Source/Application-Protocols/coreSNTP"]
+	path = FreeRTOS-Plus/Source/Application-Protocols/coreSNTP
+	url = https://github.com/FreeRTOS/coreSNTP.git
diff --git a/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/DemoTasks/SNTPClientTask.c b/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/DemoTasks/SNTPClientTask.c
new file mode 100755
index 000000000..e0501dc82
--- /dev/null
+++ b/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/DemoTasks/SNTPClientTask.c
@@ -0,0 +1,802 @@
+/*
+ * FreeRTOS V202104.00
+ * Copyright (C) 2021 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+ * the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * https://www.FreeRTOS.org
+ * https://github.com/FreeRTOS
+ *
+ */
+
+/*
+ * This file is part of the demo project that shows use of the coreSNTP library to create
+ * an SNTP client (daemon) task for synchronizing system time with internet time and
+ * maintaining Coordinated Universal Time (UTC) (or wall-clock time) in the system.
+ *
+ * This file contains the SNTP client (daemon) task as well as functionality for
+ * maintaining wall-clock or UTC time in RAM. The SNTP client periodically synchronizes
+ * system clock with an SNTP/NTP servers. Any other task running an application in the
+ * system can query the system time. For an example of an application task querying time
+ * from the system, refer to the SampleAppTask.c file in this project.
+ *
+ * !!! NOTE !!!
+ * This SNTP demo does not authenticate the server nor the client.
+ * Hence, this demo should not be used as production ready code.
+ */
+
+/* Standard includes. */
+#include <string.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <time.h>
+
+/* Kernel includes. */
+#include "FreeRTOS.h"
+#include "task.h"
+
+/* Demo include. */
+#include "common_demo_include.h"
+
+/* SNTP library include. */
+#include "core_sntp_client.h"
+
+/* Synchronization primitive include. */
+#include "semphr.h"
+
+/* FreeRTOS+TCP includes */
+#include "FreeRTOS_IP.h"
+#include "FreeRTOS_UDP_IP.h"
+#include "FreeRTOS_Sockets.h"
+
+/*-----------------------------------------------------------*/
+
+/* Compile time error for undefined configs. */
+
+#ifndef democonfigLIST_OF_TIME_SERVERS
+    #error "Define the democonfigLIST_OF_TIME_SERVERS config by following the instructions in demo_config.h file."
+#endif
+
+#ifndef democonfigDESIRED_CLOCK_ACCURACY_MS
+    #error "Define the democonfigDESIRED_CLOCK_ACCURACY_MS config by following instructions in demo_config.h file."
+#endif
+
+#ifndef democonfigSYSTEM_CLOCK_TOLERANCE_PPM
+    #error "Define the democonfigSYSTEM_CLOCK_TOLERANCE_PPM config by following instructions in demo_config.h file."
+#endif
+
+#ifndef democonfigSYSTEM_START_YEAR
+    #error "Define the democonfigSYSTEM_START_YEAR config by following instructions in demo_config.h file."
+#endif
+
+/*-----------------------------------------------------------*/
+/* Default values for configuration . */
+
+#ifndef democonfigSERVER_RESPONSE_TIMEOUT_MS
+    #define democonfigSERVER_RESPONSE_TIMEOUT_MS    ( 5000 )
+#endif
+
+/**
+ * @brief The size for network buffer that is allocated for initializing the coreSNTP library in the
+ * demo.
+ *
+ * @note The size of the buffer MUST be large enough to hold an entire SNTP packet, which includes the standard SNTP
+ * packet data of 48 bytes and authentication data for security mechanism, if used, in communication with time server.
+ */
+#define SNTP_CONTEXT_NETWORK_BUFFER_SIZE    ( SNTP_PACKET_BASE_SIZE )
+
+/**
+ * @brief The constant for storing the number of milliseconds per FreeRTOS tick in the system.
+ * @note This value represents the time duration per tick from the perspective of the
+ * of Windows Simulator based FreeRTOS system that carries lagging clock drift in relation to
+ * internet time or UTC time. Thus, the actual time duration value per tick of the system will be
+ * larger from the perspective of internet time.
+ */
+#define MILLISECONDS_PER_TICK               ( 1000 / configTICK_RATE_HZ )
+
+/*-----------------------------------------------------------*/
+
+/**
+ * @brief The definition of the @ref NetworkContext_t structure for the demo.
+ * The structure wraps a FreeRTOS+TCP socket that is used for UDP communication
+ * with time servers.
+ *
+ * @note The context is used in the @ref UdpTransportInterface_t interface required
+ * by the coreSNTP library.
+ *
+ */
+struct NetworkContext
+{
+    Socket_t socket;
+};
+
+/**
+ * @brief Structure aggregating state variables for RAM-based wall-clock time
+ * in Coordinated Universal Time (UTC) for system.
+ *
+ * @note This demo uses the following mathematical model to represent current
+ * time in RAM.
+ *
+ *  BaseTime = Time set at boot or the last synchronized time
+ *  Slew Rate = Number of seconds to adjust per system time second
+ *  No. of ticks since last SNTP sync = Current FreeRTOS Tick Count -
+ *                                      Tick count at last SNTP sync
+ *
+ *  Time Elapsed since last SNTP sync = No. of ticks since last SNTP sync
+ *                                                    x
+ *                                      Number of milliseconds per FreeRTOS tick
+ *
+ *  Slew Adjustment = Slew Rate x Time Elapsed since last SNTP sync
+ *
+ *  Current Time = Base Time +
+ *                 Time Elapsed since last SNTP sync +
+ *                 Slew Adjustment
+ */
+typedef struct SystemClock
+{
+    UTCTime_t baseTime;
+    TickType_t lastSyncTickCount;
+    uint32_t pollPeriod;
+    uint32_t slewRate; /* Seconds/Seconds */
+    bool firstTimeSyncDone;
+} SystemClock_t;
+
+/**
+ * @brief Shared global system clock object for representing UTC/wall-clock
+ * time in system.
+ */
+static SystemClock_t systemClock;
+
+/**
+ * @brief Mutex for protecting access to the shared memory of the
+ * system clock parameters.
+ */
+static SemaphoreHandle_t xMutex = NULL;
+static StaticSemaphore_t xSemaphoreMutex;
+
+/*-----------------------------------------------------------*/
+
+/**
+ * @brief Utility function to convert the passed year to UNIX time representation
+ * of seconds since 1st Jan 1970 00h:00m:00s seconds to 1st Jan 00h:00m:00s of the
+ * the passed year.
+ *
+ * This utility does account for leap years.
+ *
+ * @param[in] The year to translate.
+ */
+static uint32_t translateYearToUnixSeconds( uint16_t year );
+
+/**
+ * @brief Calculates the current time in the system.
+ * It calculates the current time as:
+ *
+ *   BaseTime = Time set at device boot or the last synchronized time
+ *   SlewRate = Number of seconds to adjust per system time second
+ *
+ *   Current Time = Base Time +
+ *                  Time since last SNTP Synchronization +
+ *                  Slew Adjustment (if slew rate > 0) for time period since
+ *                  last SNTP synchronization
+ *
+ * @param[in] pBaseTime The base time in the system clock parameters.
+ * @param[in] lastSyncTickCount The tick count at the last time synchronization
+ * with a time server.
+ * @param[in] slewRate The slew rate as seconds of clock adjustment per FreeRTOS
+ * system time second.
+ * @param[out] pCurrentTime This will be populated with the calculated current
+ * UTC time in the system.
+ */
+static void calculateCurrentTime( UTCTime_t * pBaseTime,
+                                  TickType_t lastSyncTickCount,
+                                  uint32_t slewRate,
+                                  UTCTime_t * pCurrentTime );
+
+/**
+ * @brief Initializes the SNTP context for the SNTP client task.
+ * This function generates an array of the configured time servers, creates a FreeRTOS UDP socket
+ * for the UDP transport interface and initializes the passed SNTP context by calling the
+ * Sntp_Init() API of the coreSNTP library.
+ *
+ * @param[in, out] pContext The memory for the SNTP client context that will be initialized with
+ * Sntp_Init API.
+ * @param[in] pTimeServers The list of time servers configured through the democonfigLIST_OF_TIME_SERVERS
+ * macro in demo_config.h.
+ * @param[in] numOfServers The number of time servers configured in democonfigLIST_OF_TIME_SERVERS.
+ * @param[in] pContextBuffer The allocated network buffer that will be initialized in the SNTP context.
+ * @param[in] pUdpContext The memory for the network context for the UDP transport interface that will
+ * be passed to the SNTP client context. This will be filled with a UDP context created by this function.
+ *
+ * @return Returns `true` if initialization of SNTP client context is successful; otherwise `false`.
+ */
+static bool initializeSntpClient( SntpContext_t * pContext,
+                                  const char ** pTimeServers,
+                                  size_t numOfServers,
+                                  uint8_t * pContextBuffer,
+                                  size_t contextBufferSize,
+                                  NetworkContext_t * pUdpContext );
+
+/**
+ * @brief The demo implementation of the @ref SntpResolveDns_t interface to
+ * allow the coreSNTP library to resolve DNS name of a time server being
+ * used for requesting time from.
+ *
+ * @param[in] pTimeServer The time-server whose IPv4 address is to be resolved.
+ * @param[out] pIpV4Addr This is filled with the resolved IPv4 address of
+ * @p pTimeServer.
+ */
+static bool resolveDns( const SntpServerInfo_t * pServerAddr,
+                        uint32_t * pIpV4Addr );
+
+/**
+ * @brief The demo implementation of the @ref UdpTransportSendTo_t function
+ * of the UDP transport interface to allow the coreSNTP library to perform
+ * network operation of sending time request over UDP to the provided time server.
+ *
+ * @param[in] pNetworkContext This will be the NetworkContext_t context object
+ * representing the FreeRTOS UDP socket to use for network send operation.
+ * @param[in] serverAddr The IPv4 address of the time server.
+ * @param[in] serverPort The port of the server to send data to.
+ * @param[in] pBuffer The demo-supplied network buffer of size, SNTP_CONTEXT_NETWORK_BUFFER_SIZE,
+ * containing the data to send over the network.
+ * @param[in] bytesToSend The size of data in @p pBuffer to send.
+ *
+ * @return Returns the return code of FreeRTOS UDP send API, FreeRTOS_sendto, which returns
+ * 0 for error or timeout OR the number of bytes sent over the network.
+ */
+static int32_t UdpTransport_Send( NetworkContext_t * pNetworkContext,
+                                  uint32_t serverAddr,
+                                  uint16_t serverPort,
+                                  const void * pBuffer,
+                                  size_t bytesToSend );
+
+/**
+ * @brief The demo implementation of the @ref UdpTransportRecvFrom_t function
+ * of the UDP transport interface to allow the coreSNTP library to perform
+ * network operation of reading expected time response over UDP from
+ * provided time server.
+ *
+ * @param[in] pNetworkContext This will be the NetworkContext_t context object
+ * representing the FreeRTOS UDP socket to use for network read operation.
+ * @param[in] pTimeServer The IPv4 address of the time server to receive data from.
+ * @param[in] serverPort The port of the server to receive data from.
+ * @param[out] pBuffer The demo-supplied network buffer of size, SNTP_CONTEXT_NETWORK_BUFFER_SIZE,
+ * that will be filled with data received from the network.
+ * @param[in] bytesToRecv The expected number of bytes to receive from the network
+ * for the server response server.
+ *
+ * @return Returns one of the following:
+ * - 0 for timeout in receiving any data from the network (by translating the
+ * -pdFREERTOS_ERRNO_EWOULDBLOCK return code from FreeRTOS_recvfrom API )
+ *                         OR
+ * - The number of bytes read from the network.
+ */
+static int32_t UdpTransport_Recv( NetworkContext_t * pNetworkContext,
+                                  uint32_t serverAddr,
+                                  uint16_t serverPort,
+                                  void * pBuffer,
+                                  size_t bytesToRecv );
+
+/**
+ * @brief The demo implementation of the @ref SntpGetTime_t interface
+ * for obtaining system clock time for the coreSNTP library.
+ *
+ * @param[out] pTime This will be populated with the current time from
+ * the system.
+ */
+static void sntpClient_GetTime( SntpTimestamp_t * pCurrentTime );
+
+/**
+ * @brief The demo implementation of the @ref SntpSetTime_t interface
+ * for correcting the system clock time based on the  time received
+ * from the server response and the clock-offset value calculated by
+ * the coreSNTP library.
+ *
+ * @note This demo uses either the "slew" OR "step" methodology of system
+ * clock correction based on the use-case:
+ * 1. "Step" correction is used if:
+ *   - System time is ahead of server time so that system time is immediately
+ *     corrected instead of potentially receding back in time with a "slew"
+ *     correction approach.
+ *                                      OR
+ *   - It is the first time synchronization for the system since boot-up. Using
+ *     "step" approach immediately corrects the system if it is far away from the
+ *     server time on device startup instead of slowly correcting over time with
+ *     the "slew" approach.
+ *
+ * 2. The "slew" correction approach is used for all cases other than the above
+ *    as they represent regular time synchronization during device runtime where
+ *    the system time may have drifted behind the server time, and can be corrected
+ *    gradually over the SNTP client's polling interval period.
+ *
+ * @note The above system clock correction algorithm is just one example of a correction
+ * approach. It can be modified to suit your application needs. Examples include:
+ * - Always using "slew" correction if the device is always within a small time offset from
+ *   server and your application is sensitive to non-abrupt changes in time (that could occur
+ *   with "step" approach) for use-cases like logging events in correct order
+ * - Always using a "step" approach for a simplicity if your application is not sensitive to
+ *   abrupt changes/progress in time.
+ */
+static void sntpClient_SetTime( const SntpServerInfo_t * pTimeServer,
+                                const SntpTimestamp_t * pServerTime,
+                                int32_t clockOffsetSec,
+                                SntpLeapSecondInfo_t leapSecondInfo );
+
+
+/*------------------------------------------------------------------------------*/
+
+static uint32_t translateYearToUnixSeconds( uint16_t year )
+{
+    configASSERT( year >= 1970 );
+
+    uint32_t numOfDaysSince1970 = ( year - 1970 ) * 365;
+
+    /* Calculate the extra days in leap years (for February 29) over the time
+    * period from 1st Jan 1970 to 1st Jan of the passed year.
+    * By subtracting from the year 1969, the extra day in 1972 is covered. */
+    numOfDaysSince1970 += ( ( year - 1969 ) / 4 );
+
+    return( numOfDaysSince1970 * 24 * 3600 );
+}
+
+void calculateCurrentTime( UTCTime_t * pBaseTime,
+                           TickType_t lastSyncTickCount,
+                           uint32_t slewRate,
+                           UTCTime_t * pCurrentTime )
+{
+    uint64_t msElapsedSinceLastSync = 0;
+    TickType_t ticksElapsedSinceLastSync = xTaskGetTickCount() - lastSyncTickCount;
+
+    /* Calculate time elapsed since last synchronization according to the number
+     * of system ticks passed. */
+    msElapsedSinceLastSync = ticksElapsedSinceLastSync * MILLISECONDS_PER_TICK;
+
+    /* If slew rate is set, then apply the slew-based clock adjustment for the elapsed time. */
+    if( slewRate > 0 )
+    {
+        msElapsedSinceLastSync += ( uint64_t ) slewRate * msElapsedSinceLastSync;
+    }
+
+    /* Set the current UTC time in the output parameter. */
+    if( msElapsedSinceLastSync >= 1000 )
+    {
+        pCurrentTime->secs = pBaseTime->secs + msElapsedSinceLastSync / 1000;
+        pCurrentTime->msecs = msElapsedSinceLastSync % 1000;
+    }
+    else
+    {
+        pCurrentTime->secs = pBaseTime->secs;
+        pCurrentTime->msecs = msElapsedSinceLastSync;
+    }
+}
+
+/********************** DNS Resolution Interface *******************************/
+static bool resolveDns( const SntpServerInfo_t * pServerAddr,
+                        uint32_t * pIpV4Addr )
+{
+    uint32_t resolvedAddr = 0;
+    bool status = false;
+
+    resolvedAddr = FreeRTOS_gethostbyname( pServerAddr->pServerName );
+
+    /* Set the output parameter if DNS look up succeeded. */
+    if( resolvedAddr != 0 )
+    {
+        /* DNS Look up succeeded. */
+        status = true;
+
+        *pIpV4Addr = resolvedAddr;
+
+        #if defined( LIBRARY_LOG_LEVEL ) && ( LIBRARY_LOG_LEVEL != LOG_NONE )
+            uint8_t stringAddr[ 16 ];
+            FreeRTOS_inet_ntoa( resolvedAddr, stringAddr );
+            LogInfo( ( "Resolved time server as %s", stringAddr ) );
+        #endif
+    }
+
+    return status;
+}
+
+/********************** UDP Interface definition *******************************/
+int32_t UdpTransport_Send( NetworkContext_t * pNetworkContext,
+                           uint32_t serverAddr,
+                           uint16_t serverPort,
+                           const void * pBuffer,
+                           size_t bytesToSend )
+{
+    struct freertos_sockaddr destinationAddress;
+    int32_t bytesSent;
+
+    destinationAddress.sin_addr = serverAddr;
+    destinationAddress.sin_port = FreeRTOS_htons( serverPort );
+
+    /* Send the buffer with ulFlags set to 0, so the FREERTOS_ZERO_COPY bit
+     * is clear. */
+    bytesSent = FreeRTOS_sendto( /* The socket being send to. */
+        pNetworkContext->socket,
+        /* The data being sent. */
+        pBuffer,
+        /* The length of the data being sent. */
+        bytesToSend,
+        /* ulFlags with the FREERTOS_ZERO_COPY bit clear. */
+        0,
+        /* Where the data is being sent. */
+        &destinationAddress,
+        /* Not used but should be set as shown. */
+        sizeof( destinationAddress )
+        );
+
+    return bytesSent;
+}
+
+static int32_t UdpTransport_Recv( NetworkContext_t * pNetworkContext,
+                                  uint32_t serverAddr,
+                                  uint16_t serverPort,
+                                  void * pBuffer,
+                                  size_t bytesToRecv )
+{
+    struct freertos_sockaddr sourceAddress;
+    int32_t bytesReceived;
+    socklen_t addressLength = sizeof( struct freertos_sockaddr );
+
+    /* Receive into the buffer with ulFlags set to 0, so the FREERTOS_ZERO_COPY bit
+     * is clear. */
+    bytesReceived = FreeRTOS_recvfrom( /* The socket data is being received on. */
+        pNetworkContext->socket,
+
+        /* The buffer into which received data will be
+         * copied. */
+        pBuffer,
+
+        /* The length of the buffer into which data will be
+         * copied. */
+        bytesToRecv,
+        /* ulFlags with the FREERTOS_ZERO_COPY bit clear. */
+        0,
+        /* Will get set to the source of the received data. */
+        &sourceAddress,
+        /* Not used but should be set as shown. */
+        &addressLength
+        );
+
+    /* If data is received from the network, discard the data if  received from a different source than
+     * the server. */
+    if( ( bytesReceived > 0 ) && ( ( sourceAddress.sin_addr != serverAddr ) ||
+                                   ( FreeRTOS_ntohs( sourceAddress.sin_port ) != serverPort ) ) )
+    {
+        bytesReceived = 0;
+
+        #if defined( LIBRARY_LOG_LEVEL ) && ( LIBRARY_LOG_LEVEL != LOG_NONE )
+            /* Convert the IP address of the sender's address to string for logging. */
+            char stringAddr[ 16 ];
+            FreeRTOS_inet_ntoa( sourceAddress.sin_addr, stringAddr );
+
+            /* Log about reception of packet from unexpected sender. */
+            LogWarn( ( "Received UDP packet from unexpected source: Addr=%s Port=%u",
+                       stringAddr, FreeRTOS_ntohs( sourceAddress.sin_port ) ) );
+        #endif
+    }
+
+    /* Translate the return code of timeout to the UDP transport interface expected
+     * code to indicate read retry. */
+    else if( bytesReceived == -pdFREERTOS_ERRNO_EWOULDBLOCK )
+    {
+        bytesReceived = 0;
+    }
+
+    return bytesReceived;
+}
+
+
+/**************************** Time Interfaces ************************************************/
+static void sntpClient_GetTime( SntpTimestamp_t * pCurrentTime )
+{
+    UTCTime_t currentTime;
+    uint64_t ntpSecs;
+
+    /* Obtain mutex for accessing system clock variables */
+    xSemaphoreTake( xMutex, portMAX_DELAY );
+
+    calculateCurrentTime( &systemClock.baseTime,
+                          systemClock.lastSyncTickCount,
+                          systemClock.slewRate,
+                          &currentTime );
+
+    /* Release mutex. */
+    xSemaphoreGive( xMutex );
+
+    /* Convert UTC time from UNIX timescale to SNTP timestamp format. */
+    ntpSecs = currentTime.secs + SNTP_TIME_AT_UNIX_EPOCH_SECS;
+
+    /* Support case of SNTP timestamp rollover on 7 February 2036 when
+     * converting from UNIX time to SNTP timestamp. */
+    if( ntpSecs > UINT32_MAX )
+    {
+        /* Subtract an extra second as timestamp 0 represents the epoch for
+         * NTP era 1. */
+        pCurrentTime->seconds = ntpSecs - UINT32_MAX - 1;
+    }
+    else
+    {
+        pCurrentTime->seconds = ntpSecs;
+    }
+
+    pCurrentTime->fractions = MILLISECONDS_TO_SNTP_FRACTIONS( currentTime.msecs );
+}
+
+static void sntpClient_SetTime( const SntpServerInfo_t * pTimeServer,
+                                const SntpTimestamp_t * pServerTime,
+                                int32_t clockOffsetSec,
+                                SntpLeapSecondInfo_t leapSecondInfo )
+{
+    /* TODO - Handle leap second. */
+    ( void ) leapSecondInfo;
+
+    ( void ) pTimeServer;
+
+    /* Obtain the mutext for accessing system clock variables. */
+    xSemaphoreTake( xMutex, portMAX_DELAY );
+
+    /* Use "step" approach if:
+     * The system clock has drifted ahead of server time.
+     *                         OR
+     * This is the first time synchronization with NTP server since device boot-up.
+     */
+    if( ( clockOffsetSec < 0 ) || ( systemClock.firstTimeSyncDone == false ) )
+    {
+        SntpStatus_t status;
+        uint32_t unixSecs;
+        uint32_t unixMicroSecs;
+
+        /* Convert server time from NTP timestamp to UNIX format. */
+        status = Sntp_ConvertToUnixTime( pServerTime,
+                                         &unixSecs,
+                                         &unixMicroSecs );
+        configASSERT( status == SntpSuccess );
+
+        /* Immediately correct the base time of the system clock as server time. */
+        systemClock.baseTime.secs = unixSecs;
+        systemClock.baseTime.msecs = unixMicroSecs / 1000;
+
+        /* Reset slew rate to zero as the time has been immediately corrected to server time. */
+        systemClock.slewRate = 0;
+
+        /* Store the tick count of the current time synchronization in the system clock. */
+        systemClock.lastSyncTickCount = xTaskGetTickCount();
+
+        /* Set the system clock flag that indicates completion of the first time synchronization since device boot-up. */
+        if( systemClock.firstTimeSyncDone == false )
+        {
+            systemClock.firstTimeSyncDone = true;
+        }
+    }
+
+    /* As the system clock is behind server time, we will use a "slew" approach to gradually
+     * correct system time over the poll interval period. */
+    else
+    {
+        /* Update the base time based on the previous slew rate and the time period transpired
+         * since last time synchronization. */
+        calculateCurrentTime( &systemClock.baseTime,
+                              systemClock.lastSyncTickCount,
+                              systemClock.slewRate,
+                              &systemClock.baseTime );
+
+        /* Calculate the new slew rate as offset in seconds of adjustment per second. */
+        systemClock.slewRate = clockOffsetSec / systemClock.pollPeriod;
+
+        /* Store the tick count of the current time synchronization in the system clock. */
+        systemClock.lastSyncTickCount = xTaskGetTickCount();
+    }
+
+    xSemaphoreGive( xMutex );
+}
+
+/*************************************************************************************/
+
+void initializeSystemClock( void )
+{
+    /* On boot-up initialize the system time as the first second in the configured year. */
+    int64_t startupTimeInUnixSecs = translateYearToUnixSeconds( democonfigSYSTEM_START_YEAR );
+
+    systemClock.baseTime.secs = startupTimeInUnixSecs;
+    systemClock.baseTime.msecs = 0;
+
+    LogInfo( ( "System time has been initialized to the year %u", democonfigSYSTEM_START_YEAR ) );
+    printTime( &systemClock.baseTime );
+
+    /* Initialize semaphore for guarding access to system clock variables. */
+    xMutex = xSemaphoreCreateMutexStatic( &xSemaphoreMutex );
+    configASSERT( xMutex );
+
+    /* Clear the first time sync completed flag of the system clock object so that a "step" correction
+     * of system time is utilized for the first time synchronization from a time server. */
+    systemClock.firstTimeSyncDone = false;
+}
+
+/*-----------------------------------------------------------*/
+
+static bool initializeSntpClient( SntpContext_t * pContext,
+                                  const char ** pTimeServers,
+                                  size_t numOfServers,
+                                  uint8_t * pContextBuffer,
+                                  size_t contextBufferSize,
+                                  NetworkContext_t * pUdpContext )
+{
+    bool initStatus = false;
+
+    /* Populate the list of time servers. */
+    SntpServerInfo_t * pServers = pvPortMalloc( sizeof( SntpServerInfo_t ) * numOfServers );
+
+    if( pServers == NULL )
+    {
+        LogError( ( "Unable to initialize SNTP client: Malloc failed for memory of configured time servers." ) );
+    }
+    else
+    {
+        for( int8_t index = 0; index < numOfServers; index++ )
+        {
+            pServers[ index ].pServerName = pTimeServers[ index ];
+            pServers[ index ].port = SNTP_DEFAULT_SERVER_PORT;
+        }
+
+        LogInfo( ( "Calculated poll interval: %lus", systemClock.pollPeriod ) );
+
+        /* Create a UDP socket for network I/O with server. */
+        pUdpContext->socket = FreeRTOS_socket( FREERTOS_AF_INET,
+                                               FREERTOS_SOCK_DGRAM,
+                                               FREERTOS_IPPROTO_UDP );
+
+        /* Check the socket was created successfully. */
+        /* TODO - Consider using random port assigned by FreeRTOS for better protection */
+        /* against "off-path" attacker. */
+        if( pUdpContext->socket == FREERTOS_INVALID_SOCKET )
+        {
+            /* There was insufficient FreeRTOS heap memory available for the socket
+             * to be created. */
+            LogError( ( "Failed to create UDP socket for SNTP client due to insufficient memory." ) );
+        }
+        else
+        {
+            struct freertos_sockaddr bindAddress;
+            UdpTransportInterface_t udpTransportIntf;
+
+            bindAddress.sin_port = FreeRTOS_htons( SNTP_DEFAULT_SERVER_PORT );
+
+            if( FreeRTOS_bind( pUdpContext->socket, &bindAddress, sizeof( bindAddress ) ) == 0 )
+            {
+                /* The bind was successful. */
+                LogDebug( ( "UDP socket has been bound to port %lu", SNTP_DEFAULT_SERVER_PORT ) );
+            }
+
+            /* Set the UDP transport interface object. */
+            udpTransportIntf.pUserContext = pUdpContext;
+            udpTransportIntf.sendTo = UdpTransport_Send;
+            udpTransportIntf.recvFrom = UdpTransport_Recv;
+
+            /* Initialize context. */
+            Sntp_Init( pContext,
+                       pServers,
+                       numOfServers,
+                       democonfigSERVER_RESPONSE_TIMEOUT_MS,
+                       pContextBuffer,
+                       contextBufferSize,
+                       resolveDns,
+                       sntpClient_GetTime,
+                       sntpClient_SetTime,
+                       &udpTransportIntf,
+                       NULL );
+
+            initStatus = true;
+        }
+    }
+
+    return initStatus;
+}
+
+/*-----------------------------------------------------------*/
+
+void sntpTask( void * pParameters )
+{
+    SntpContext_t clientContext;
+    bool initStatus = false;
+
+    /* Variable representing the SNTP client context. */
+    static SntpContext_t context;
+
+    /* Memory for the SNTP packet buffer in the SNTP context. */
+    static uint8_t contextBuffer[ SNTP_CONTEXT_NETWORK_BUFFER_SIZE ];
+
+    /* Memory for the network context representing the UDP socket that will be
+     * passed to the SNTP client context. */
+    static NetworkContext_t udpContext;
+
+    /* Store the configured time servers in an array. */
+    static const char * pTimeServers[] = { democonfigLIST_OF_TIME_SERVERS };
+    const size_t numOfServers = sizeof( pTimeServers ) / sizeof( char * );
+
+    initStatus = initializeSntpClient( &clientContext,
+                                       pTimeServers,
+                                       numOfServers,
+                                       contextBuffer,
+                                       sizeof( contextBuffer ),
+                                       &udpContext );
+
+    if( initStatus == true )
+    {
+        SntpStatus_t status;
+
+        /* Calculate Poll interval of SNTP client based on desired accuracy and clock tolerance of the system. */
+        status = Sntp_CalculatePollInterval( democonfigSYSTEM_CLOCK_TOLERANCE_PPM,
+                                             democonfigDESIRED_CLOCK_ACCURACY_MS,
+                                             &systemClock.pollPeriod );
+        configASSERT( status == SntpSuccess );
+
+        LogInfo( ( "Initialized SNTP Client context. Starting the SNTP client loop for time synchronization every %lu seconds",
+                   systemClock.pollPeriod ) );
+
+        /* SNTP Client loop of sending and receiving SNTP packets for time synchronization at poll intervals */
+        while( 1 )
+        {
+            /* TODO - Generate random number with corePKCS11. */
+            status = Sntp_SendTimeRequest( &clientContext, 100 );
+            configASSERT( status == SntpSuccess );
+
+            /* Wait till the server response is not received. */
+            do
+            {
+                /* Attempt to receive server response each time for 200 ms. */
+                status = Sntp_ReceiveTimeResponse( &clientContext, 200 );
+            } while( status == SntpNoResponseReceived );
+
+            /* Wait for the poll interval period before the next iteration of time synchronization. */
+            vTaskDelay( pdMS_TO_TICKS( systemClock.pollPeriod * 1000 ) );
+        }
+    }
+    else
+    {
+        configASSERT( false );
+
+        /* Terminate the task as the SNTP client failed to be run. */
+        LogError( ( "Failed to initialize SNTP client. Terminating SNTP client task.." ) );
+
+        vTaskDelete( NULL );
+    }
+}
+
+/*-----------------------------------------------------------*/
+
+void systemGetWallClockTime( UTCTime_t * pTime )
+{
+    TickType_t xTickCount = 0;
+    uint32_t ulTimeMs = 0UL;
+
+    /* Obtain the mutext for accessing system clock variables. */
+    xSemaphoreTake( xMutex, portMAX_DELAY );
+
+    /* Calculate the current RAM-based time using a mathematical formula using
+     * system clock state parameters and the time transpired since last synchronization. */
+    calculateCurrentTime( &systemClock.baseTime,
+                          systemClock.lastSyncTickCount,
+                          systemClock.slewRate,
+                          pTime );
+
+    xSemaphoreGive( xMutex );
+}
+
+/*-----------------------------------------------------------*/
diff --git a/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/DemoTasks/SampleAppTask.c b/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/DemoTasks/SampleAppTask.c
new file mode 100755
index 000000000..53cdb527f
--- /dev/null
+++ b/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/DemoTasks/SampleAppTask.c
@@ -0,0 +1,92 @@
+/*
+ * FreeRTOS V202104.00
+ * Copyright (C) 2021 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+ * the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * https://www.FreeRTOS.org
+ * https://github.com/FreeRTOS
+ *
+ */
+
+/*
+ * This file belongs to the demo for showing use of the coreSNTP library for synchronizing
+ * system time with internet time and maintaining correct wall-clock time.
+ *
+ * This file shows how an application task can query Coordinated Universal Time (UTC) from system,
+ * that is maintained and synchronized periodically in the SNTP client (daemon) task of the demo
+ * project. Refer to the the SNTPClientTask.c file in this project for the SNTP client task.
+ */
+
+/* Standard includes. */
+#include <string.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <time.h>
+
+/* Kernel includes. */
+#include "FreeRTOS.h"
+#include "task.h"
+
+/* Demo includes. */
+#include "common_demo_include.h"
+
+/*-----------------------------------------------------------*/
+
+/**
+ * @brief The periodicity of the application task in query and logging system time. This is the time
+ * interval between consecutive system clock time queries in the sample application task.
+ */
+#define CLOCK_QUERY_TASK_DELAY_MS    ( 1000 )
+
+/*-----------------------------------------------------------*/
+
+void printTime( const UTCTime_t * pUnixTime )
+{
+    struct tm * currTime;
+    time_t time;
+
+    /* Obtain the broken-down UTC representation of the current system time. */
+    time = pUnixTime->secs;
+    currTime = gmtime( &time );
+
+    /* Log the time as both UNIX timestamp and Human Readable time. */
+    LogInfo( ( "Time:\nUNIX=%lusecs %lums\nHuman Readable=%lu-%02lu-%02lu %02luh:%02lum:%02lus",
+               pUnixTime->secs, pUnixTime->msecs,
+               currTime->tm_year + 1900, currTime->tm_mon + 1, currTime->tm_mday,
+               currTime->tm_hour, currTime->tm_min, currTime->tm_sec ) );
+}
+
+/*************************************************************************************/
+
+/* Sample application task that will query and log system time every second. */
+void sampleAppTask( void * pvParameters )
+{
+    UTCTime_t systemTime;
+
+    while( 1 )
+    {
+        systemGetWallClockTime( &systemTime );
+
+        printTime( &systemTime );
+
+        vTaskDelay( pdMS_TO_TICKS( CLOCK_QUERY_TASK_DELAY_MS ) );
+    }
+}
+
+/*-----------------------------------------------------------*/
diff --git a/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/FreeRTOSConfig.h b/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/FreeRTOSConfig.h
new file mode 100755
index 000000000..9cb3f1856
--- /dev/null
+++ b/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/FreeRTOSConfig.h
@@ -0,0 +1,203 @@
+/*
+ * FreeRTOS V202104.00
+ * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+ * the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * http://www.FreeRTOS.org
+ * http://aws.amazon.com/freertos
+ *
+ * 1 tab == 4 spaces!
+ */
+
+#ifndef FREERTOS_CONFIG_H
+#define FREERTOS_CONFIG_H
+
+/*-----------------------------------------------------------
+* Application specific definitions.
+*
+* These definitions should be adjusted for your particular hardware and
+* application requirements.
+*
+* THESE PARAMETERS ARE DESCRIBED WITHIN THE 'CONFIGURATION' SECTION OF THE
+* FreeRTOS API DOCUMENTATION AVAILABLE ON THE FreeRTOS.org WEB SITE.
+* http://www.freertos.org/a00110.html
+*
+* The bottom of this file contains some constants specific to running the UDP
+* stack in this demo.  Constants specific to FreeRTOS+TCP itself (rather than
+* the demo) are contained in FreeRTOSIPConfig.h.
+*----------------------------------------------------------*/
+#define configUSE_PREEMPTION                       1
+#define configUSE_PORT_OPTIMISED_TASK_SELECTION    1
+#define configMAX_PRIORITIES                       ( 7 )
+#define configTICK_RATE_HZ                         ( 1000 )                  /* In this non-real time simulated environment the tick frequency has to be at least a multiple of the Win32 tick frequency, and therefore very slow. */
+#define configMINIMAL_STACK_SIZE                   ( ( unsigned short ) 60 ) /* In this simulated case, the stack only has to hold one small structure as the real stack is part of the Win32 thread. */
+#define configTOTAL_HEAP_SIZE                      ( ( size_t ) ( 2048U * 1024U ) )
+#define configMAX_TASK_NAME_LEN                    ( 15 )
+#define configUSE_TRACE_FACILITY                   0
+#define configUSE_16_BIT_TICKS                     0
+#define configIDLE_SHOULD_YIELD                    1
+#define configUSE_CO_ROUTINES                      0
+#define configUSE_MUTEXES                          1
+#define configUSE_RECURSIVE_MUTEXES                1
+#define configQUEUE_REGISTRY_SIZE                  0
+#define configUSE_APPLICATION_TASK_TAG             0
+#define configUSE_COUNTING_SEMAPHORES              1
+#define configUSE_ALTERNATIVE_API                  0
+#define configNUM_THREAD_LOCAL_STORAGE_POINTERS    0
+#define configENABLE_BACKWARD_COMPATIBILITY        1
+#define configSUPPORT_STATIC_ALLOCATION            1
+#define configUSE_STATS_FORMATTING_FUNCTIONS       0
+
+/* Hook function related definitions. */
+#define configUSE_TICK_HOOK                        0
+#define configUSE_IDLE_HOOK                        0
+#define configUSE_MALLOC_FAILED_HOOK               0
+#define configCHECK_FOR_STACK_OVERFLOW             0 /* Not applicable to the Win32 port. */
+
+/* Software timer related definitions. */
+#define configUSE_TIMERS                           1
+#define configTIMER_TASK_PRIORITY                  ( configMAX_PRIORITIES - 1 )
+#define configTIMER_QUEUE_LENGTH                   5
+#define configTIMER_TASK_STACK_DEPTH               ( configMINIMAL_STACK_SIZE * 2 )
+
+/* Event group related definitions. */
+#define configUSE_EVENT_GROUPS                     1
+
+/* Run time stats gathering configuration options. */
+#define configGENERATE_RUN_TIME_STATS              0
+
+/* Co-routine definitions. */
+#define configUSE_CO_ROUTINES                      0
+#define configMAX_CO_ROUTINE_PRIORITIES            ( 2 )
+
+/* Set the following definitions to 1 to include the API function, or zero
+ * to exclude the API function. */
+#define INCLUDE_vTaskPrioritySet                   1
+#define INCLUDE_uxTaskPriorityGet                  1
+#define INCLUDE_vTaskDelete                        1
+#define INCLUDE_vTaskCleanUpResources              0
+#define INCLUDE_vTaskSuspend                       1
+#define INCLUDE_vTaskDelayUntil                    1
+#define INCLUDE_vTaskDelay                         1
+#define INCLUDE_uxTaskGetStackHighWaterMark        1
+#define INCLUDE_xTaskGetSchedulerState             1
+#define INCLUDE_xTimerGetTimerTaskHandle           0
+#define INCLUDE_xTaskGetIdleTaskHandle             0
+#define INCLUDE_xQueueGetMutexHolder               1
+#define INCLUDE_eTaskGetState                      1
+#define INCLUDE_xEventGroupSetBitsFromISR          1
+#define INCLUDE_xTimerPendFunctionCall             1
+#define INCLUDE_pcTaskGetTaskName                  1
+
+/* Assert call defined for debug builds. */
+#ifdef _DEBUG
+    extern void vAssertCalled( const char * pcFile,
+                               uint32_t ulLine );
+    #define configASSERT( x )    if( ( x ) == 0 ) vAssertCalled( __FILE__, __LINE__ )
+#endif /* _DEBUG */
+
+
+
+/* Application specific definitions follow. **********************************/
+
+/* Only used when running in the FreeRTOS Windows simulator.  Defines the
+ * priority of the task used to simulate Ethernet interrupts. */
+#define configMAC_ISR_SIMULATOR_PRIORITY    ( configMAX_PRIORITIES - 1 )
+
+/* This demo creates a virtual network connection by accessing the raw Ethernet
+ * or WiFi data to and from a real network connection.  Many computers have more
+ * than one real network port, and configNETWORK_INTERFACE_TO_USE is used to tell
+ * the demo which real port should be used to create the virtual port.  The ports
+ * available are displayed on the console when the application is executed.  For
+ * example, on my development laptop setting configNETWORK_INTERFACE_TO_USE to 4
+ * results in the wired network being used, while setting
+ * configNETWORK_INTERFACE_TO_USE to 2 results in the wireless network being
+ * used. */
+#define configNETWORK_INTERFACE_TO_USE      ( 2L )
+
+/* The address to which logging is sent should UDP logging be enabled. */
+#define configUDP_LOGGING_ADDR0             192
+#define configUDP_LOGGING_ADDR1             168
+#define configUDP_LOGGING_ADDR2             0
+#define configUDP_LOGGING_ADDR3             11
+
+/* Default MAC address configuration.  The demo creates a virtual network
+ * connection that uses this MAC address by accessing the raw Ethernet/WiFi data
+ * to and from a real network connection on the host PC.  See the
+ * configNETWORK_INTERFACE_TO_USE definition above for information on how to
+ * configure the real network connection to use. */
+#define configMAC_ADDR0                     0x00
+#define configMAC_ADDR1                     0x11
+#define configMAC_ADDR2                     0x11
+#define configMAC_ADDR3                     0x11
+#define configMAC_ADDR4                     0x11
+#define configMAC_ADDR5                     0x41
+
+/* Default IP address configuration.  Used in ipconfigUSE_DNS is set to 0, or
+ * ipconfigUSE_DNS is set to 1 but a DNS server cannot be contacted. */
+#define configIP_ADDR0                      10
+#define configIP_ADDR1                      10
+#define configIP_ADDR2                      10
+#define configIP_ADDR3                      200
+
+/* Default gateway IP address configuration.  Used in ipconfigUSE_DNS is set to
+ * 0, or ipconfigUSE_DNS is set to 1 but a DNS server cannot be contacted. */
+#define configGATEWAY_ADDR0                 10
+#define configGATEWAY_ADDR1                 10
+#define configGATEWAY_ADDR2                 10
+#define configGATEWAY_ADDR3                 1
+
+/* Default DNS server configuration.  OpenDNS addresses are 208.67.222.222 and
+ * 208.67.220.220.  Used in ipconfigUSE_DNS is set to 0, or ipconfigUSE_DNS is set
+ * to 1 but a DNS server cannot be contacted.*/
+#define configDNS_SERVER_ADDR0              208
+#define configDNS_SERVER_ADDR1              67
+#define configDNS_SERVER_ADDR2              222
+#define configDNS_SERVER_ADDR3              222
+
+/* Default netmask configuration.  Used in ipconfigUSE_DNS is set to 0, or
+ * ipconfigUSE_DNS is set to 1 but a DNS server cannot be contacted. */
+#define configNET_MASK0                     255
+#define configNET_MASK1                     0
+#define configNET_MASK2                     0
+#define configNET_MASK3                     0
+
+/* The UDP port to which print messages are sent. */
+#define configPRINT_PORT                    ( 15000 )
+
+
+#if ( defined( _MSC_VER ) && ( _MSC_VER <= 1600 ) && !defined( snprintf ) )
+    /* Map to Windows names. */
+    #define snprintf     _snprintf
+    #define vsnprintf    _vsnprintf
+#endif
+
+/* Visual studio does not have an implementation of strcasecmp(). */
+#define strcasecmp     _stricmp
+#define strncasecmp    _strnicmp
+#define strcmpi        _strcmpi
+
+/* Prototype for the function used to print out.  In this case it prints to the
+ * console before the network is connected then a UDP port after the network has
+ * connected. */
+extern void vLoggingPrintf( const char * pcFormatString,
+                            ... );
+#define configPRINTF( X )    vLoggingPrintf X
+
+#endif /* FREERTOS_CONFIG_H */
diff --git a/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/FreeRTOSIPConfig.h b/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/FreeRTOSIPConfig.h
new file mode 100755
index 000000000..47eb83cf6
--- /dev/null
+++ b/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/FreeRTOSIPConfig.h
@@ -0,0 +1,311 @@
+/*
+ * FreeRTOS V202104.00
+ * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+ * the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * http://www.FreeRTOS.org
+ * http://aws.amazon.com/freertos
+ *
+ * 1 tab == 4 spaces!
+ */
+
+
+/*****************************************************************************
+*
+* See the following URL for configuration information.
+* http://www.freertos.org/FreeRTOS-Plus/FreeRTOS_Plus_TCP/TCP_IP_Configuration.html
+*
+*****************************************************************************/
+
+#ifndef FREERTOS_IP_CONFIG_H
+#define FREERTOS_IP_CONFIG_H
+
+/* Prototype for the function used to print out.  In this case it prints to the
+ * console before the network is connected then a UDP port after the network has
+ * connected. */
+extern void vLoggingPrintf( const char * pcFormatString,
+                            ... );
+
+/* Set to 1 to print out debug messages.  If ipconfigHAS_DEBUG_PRINTF is set to
+ * 1 then FreeRTOS_debug_printf should be defined to the function used to print
+ * out the debugging messages. */
+#define ipconfigHAS_DEBUG_PRINTF    0
+#if ( ipconfigHAS_DEBUG_PRINTF == 1 )
+    #define FreeRTOS_debug_printf( X )    vLoggingPrintf X
+#endif
+
+/* Set to 1 to print out non debugging messages, for example the output of the
+ * FreeRTOS_netstat() command, and ping replies.  If ipconfigHAS_PRINTF is set to 1
+ * then FreeRTOS_printf should be set to the function used to print out the
+ * messages. */
+#define ipconfigHAS_PRINTF    1
+#if ( ipconfigHAS_PRINTF == 1 )
+    #define FreeRTOS_printf( X )    vLoggingPrintf X
+#endif
+
+/* Define the byte order of the target MCU (the MCU FreeRTOS+TCP is executing
+ * on).  Valid options are pdFREERTOS_BIG_ENDIAN and pdFREERTOS_LITTLE_ENDIAN. */
+#define ipconfigBYTE_ORDER                         pdFREERTOS_LITTLE_ENDIAN
+
+/* If the network card/driver includes checksum offloading (IP/TCP/UDP checksums)
+ * then set ipconfigDRIVER_INCLUDED_RX_IP_CHECKSUM to 1 to prevent the software
+ * stack repeating the checksum calculations. */
+#define ipconfigDRIVER_INCLUDED_RX_IP_CHECKSUM     1
+
+/* Several API's will block until the result is known, or the action has been
+ * performed, for example FreeRTOS_send() and FreeRTOS_recv().  The timeouts can be
+ * set per socket, using setsockopt().  If not set, the times below will be
+ * used as defaults. */
+#define ipconfigSOCK_DEFAULT_RECEIVE_BLOCK_TIME    ( 5000 )
+#define ipconfigSOCK_DEFAULT_SEND_BLOCK_TIME       ( 5000 )
+
+/* Include support for LLMNR: Link-local Multicast Name Resolution
+ * (non-Microsoft) */
+#define ipconfigUSE_LLMNR                          ( 0 )
+
+/* Include support for NBNS: NetBIOS Name Service (Microsoft) */
+#define ipconfigUSE_NBNS                           ( 0 )
+
+/* Include support for DNS caching.  For TCP, having a small DNS cache is very
+ * useful.  When a cache is present, ipconfigDNS_REQUEST_ATTEMPTS can be kept low
+ * and also DNS may use small timeouts.  If a DNS reply comes in after the DNS
+ * socket has been destroyed, the result will be stored into the cache.  The next
+ * call to FreeRTOS_gethostbyname() will return immediately, without even creating
+ * a socket. */
+#define ipconfigUSE_DNS_CACHE                      ( 1 )
+#define ipconfigDNS_CACHE_NAME_LENGTH              ( 32 )
+#define ipconfigDNS_CACHE_ENTRIES                  ( 4 )
+#define ipconfigDNS_REQUEST_ATTEMPTS               ( 2 )
+
+/* The IP stack executes it its own task (although any application task can make
+ * use of its services through the published sockets API). ipconfigUDP_TASK_PRIORITY
+ * sets the priority of the task that executes the IP stack.  The priority is a
+ * standard FreeRTOS task priority so can take any value from 0 (the lowest
+ * priority) to (configMAX_PRIORITIES - 1) (the highest priority).
+ * configMAX_PRIORITIES is a standard FreeRTOS configuration parameter defined in
+ * FreeRTOSConfig.h, not FreeRTOSIPConfig.h. Consideration needs to be given as to
+ * the priority assigned to the task executing the IP stack relative to the
+ * priority assigned to tasks that use the IP stack. */
+#define ipconfigIP_TASK_PRIORITY                   ( configMAX_PRIORITIES - 2 )
+
+/* The size, in words (not bytes), of the stack allocated to the FreeRTOS+TCP
+ * task.  This setting is less important when the FreeRTOS Win32 simulator is used
+ * as the Win32 simulator only stores a fixed amount of information on the task
+ * stack.  FreeRTOS includes optional stack overflow detection, see:
+ * http://www.freertos.org/Stacks-and-stack-overflow-checking.html */
+#define ipconfigIP_TASK_STACK_SIZE_WORDS           ( configMINIMAL_STACK_SIZE * 5 )
+
+/* ipconfigRAND32() is called by the IP stack to generate random numbers for
+ * things such as a DHCP transaction number or initial sequence number.  Random
+ * number generation is performed via this macro to allow applications to use their
+ * own random number generation method.  For example, it might be possible to
+ * generate a random number by sampling noise on an analogue input. */
+extern UBaseType_t uxRand();
+#define ipconfigRAND32()    uxRand()
+
+/* If ipconfigUSE_NETWORK_EVENT_HOOK is set to 1 then FreeRTOS+TCP will call the
+ * network event hook at the appropriate times.  If ipconfigUSE_NETWORK_EVENT_HOOK
+ * is not set to 1 then the network event hook will never be called.  See
+ * http://www.FreeRTOS.org/FreeRTOS-Plus/FreeRTOS_Plus_UDP/API/vApplicationIPNetworkEventHook.shtml
+ */
+#define ipconfigUSE_NETWORK_EVENT_HOOK                        1
+
+/* Sockets have a send block time attribute.  If FreeRTOS_sendto() is called but
+ * a network buffer cannot be obtained then the calling task is held in the Blocked
+ * state (so other tasks can continue to executed) until either a network buffer
+ * becomes available or the send block time expires.  If the send block time expires
+ * then the send operation is aborted.  The maximum allowable send block time is
+ * capped to the value set by ipconfigMAX_SEND_BLOCK_TIME_TICKS.  Capping the
+ * maximum allowable send block time prevents prevents a deadlock occurring when
+ * all the network buffers are in use and the tasks that process (and subsequently
+ * free) the network buffers are themselves blocked waiting for a network buffer.
+ * ipconfigMAX_SEND_BLOCK_TIME_TICKS is specified in RTOS ticks.  A time in
+ * milliseconds can be converted to a time in ticks by dividing the time in
+ * milliseconds by portTICK_PERIOD_MS. */
+#define ipconfigUDP_MAX_SEND_BLOCK_TIME_TICKS                 ( 5000 / portTICK_PERIOD_MS )
+
+/* If ipconfigUSE_DHCP is 1 then FreeRTOS+TCP will attempt to retrieve an IP
+ * address, netmask, DNS server address and gateway address from a DHCP server.  If
+ * ipconfigUSE_DHCP is 0 then FreeRTOS+TCP will use a static IP address.  The
+ * stack will revert to using the static IP address even when ipconfigUSE_DHCP is
+ * set to 1 if a valid configuration cannot be obtained from a DHCP server for any
+ * reason.  The static configuration used is that passed into the stack by the
+ * FreeRTOS_IPInit() function call. */
+#define ipconfigUSE_DHCP                                      1
+
+/* When ipconfigUSE_DHCP is set to 1, DHCP requests will be sent out at
+ * increasing time intervals until either a reply is received from a DHCP server
+ * and accepted, or the interval between transmissions reaches
+ * ipconfigMAXIMUM_DISCOVER_TX_PERIOD.  The IP stack will revert to using the
+ * static IP address passed as a parameter to FreeRTOS_IPInit() if the
+ * re-transmission time interval reaches ipconfigMAXIMUM_DISCOVER_TX_PERIOD without
+ * a DHCP reply being received. */
+#define ipconfigMAXIMUM_DISCOVER_TX_PERIOD                    ( 120000 / portTICK_PERIOD_MS )
+
+/* The ARP cache is a table that maps IP addresses to MAC addresses.  The IP
+ * stack can only send a UDP message to a remove IP address if it knowns the MAC
+ * address associated with the IP address, or the MAC address of the router used to
+ * contact the remote IP address.  When a UDP message is received from a remote IP
+ * address the MAC address and IP address are added to the ARP cache.  When a UDP
+ * message is sent to a remote IP address that does not already appear in the ARP
+ * cache then the UDP message is replaced by a ARP message that solicits the
+ * required MAC address information.  ipconfigARP_CACHE_ENTRIES defines the maximum
+ * number of entries that can exist in the ARP table at any one time. */
+#define ipconfigARP_CACHE_ENTRIES                             6
+
+/* ARP requests that do not result in an ARP response will be re-transmitted a
+ * maximum of ipconfigMAX_ARP_RETRANSMISSIONS times before the ARP request is
+ * aborted. */
+#define ipconfigMAX_ARP_RETRANSMISSIONS                       ( 5 )
+
+/* ipconfigMAX_ARP_AGE defines the maximum time between an entry in the ARP
+ * table being created or refreshed and the entry being removed because it is stale.
+ * New ARP requests are sent for ARP cache entries that are nearing their maximum
+ * age.  ipconfigMAX_ARP_AGE is specified in tens of seconds, so a value of 150 is
+ * equal to 1500 seconds (or 25 minutes). */
+#define ipconfigMAX_ARP_AGE                                   150
+
+/* Implementing FreeRTOS_inet_addr() necessitates the use of string handling
+ * routines, which are relatively large.  To save code space the full
+ * FreeRTOS_inet_addr() implementation is made optional, and a smaller and faster
+ * alternative called FreeRTOS_inet_addr_quick() is provided.  FreeRTOS_inet_addr()
+ * takes an IP in decimal dot format (for example, "192.168.0.1") as its parameter.
+ * FreeRTOS_inet_addr_quick() takes an IP address as four separate numerical octets
+ * (for example, 192, 168, 0, 1) as its parameters.  If
+ * ipconfigINCLUDE_FULL_INET_ADDR is set to 1 then both FreeRTOS_inet_addr() and
+ * FreeRTOS_indet_addr_quick() are available.  If ipconfigINCLUDE_FULL_INET_ADDR is
+ * not set to 1 then only FreeRTOS_indet_addr_quick() is available. */
+#define ipconfigINCLUDE_FULL_INET_ADDR                        1
+
+/* ipconfigNUM_NETWORK_BUFFER_DESCRIPTORS defines the total number of network buffer that
+ * are available to the IP stack.  The total number of network buffers is limited
+ * to ensure the total amount of RAM that can be consumed by the IP stack is capped
+ * to a pre-determinable value. */
+#define ipconfigNUM_NETWORK_BUFFER_DESCRIPTORS                60
+
+/* A FreeRTOS queue is used to send events from application tasks to the IP
+ * stack.  ipconfigEVENT_QUEUE_LENGTH sets the maximum number of events that can
+ * be queued for processing at any one time.  The event queue must be a minimum of
+ * 5 greater than the total number of network buffers. */
+#define ipconfigEVENT_QUEUE_LENGTH                            ( ipconfigNUM_NETWORK_BUFFER_DESCRIPTORS + 5 )
+
+/* The address of a socket is the combination of its IP address and its port
+ * number.  FreeRTOS_bind() is used to manually allocate a port number to a socket
+ * (to 'bind' the socket to a port), but manual binding is not normally necessary
+ * for client sockets (those sockets that initiate outgoing connections rather than
+ * wait for incoming connections on a known port number).  If
+ * ipconfigALLOW_SOCKET_SEND_WITHOUT_BIND is set to 1 then calling
+ * FreeRTOS_sendto() on a socket that has not yet been bound will result in the IP
+ * stack automatically binding the socket to a port number from the range
+ * socketAUTO_PORT_ALLOCATION_START_NUMBER to 0xffff.  If
+ * ipconfigALLOW_SOCKET_SEND_WITHOUT_BIND is set to 0 then calling FreeRTOS_sendto()
+ * on a socket that has not yet been bound will result in the send operation being
+ * aborted. */
+#define ipconfigALLOW_SOCKET_SEND_WITHOUT_BIND                1
+
+/* Defines the Time To Live (TTL) values used in outgoing UDP packets. */
+#define ipconfigUDP_TIME_TO_LIVE                              128
+#define ipconfigTCP_TIME_TO_LIVE                              128 /* also defined in FreeRTOSIPConfigDefaults.h */
+
+/* USE_TCP: Use TCP and all its features */
+#define ipconfigUSE_TCP                                       ( 1 )
+
+/* Use the TCP socket wake context with a callback. */
+#define ipconfigSOCKET_HAS_USER_WAKE_CALLBACK_WITH_CONTEXT    ( 1 )
+
+/* USE_WIN: Let TCP use windowing mechanism. */
+#define ipconfigUSE_TCP_WIN                                   ( 1 )
+
+/* The MTU is the maximum number of bytes the payload of a network frame can
+ * contain.  For normal Ethernet V2 frames the maximum MTU is 1500.  Setting a
+ * lower value can save RAM, depending on the buffer management scheme used.  If
+ * ipconfigCAN_FRAGMENT_OUTGOING_PACKETS is 1 then (ipconfigNETWORK_MTU - 28) must
+ * be divisible by 8. */
+#define ipconfigNETWORK_MTU                                   1200
+
+/* Set ipconfigUSE_DNS to 1 to include a basic DNS client/resolver.  DNS is used
+ * through the FreeRTOS_gethostbyname() API function. */
+#define ipconfigUSE_DNS                                       1
+
+/* If ipconfigREPLY_TO_INCOMING_PINGS is set to 1 then the IP stack will
+ * generate replies to incoming ICMP echo (ping) requests. */
+#define ipconfigREPLY_TO_INCOMING_PINGS                       1
+
+/* If ipconfigSUPPORT_OUTGOING_PINGS is set to 1 then the
+ * FreeRTOS_SendPingRequest() API function is available. */
+#define ipconfigSUPPORT_OUTGOING_PINGS                        0
+
+/* If ipconfigSUPPORT_SELECT_FUNCTION is set to 1 then the FreeRTOS_select()
+ * (and associated) API function is available. */
+#define ipconfigSUPPORT_SELECT_FUNCTION                       1
+
+/* If ipconfigFILTER_OUT_NON_ETHERNET_II_FRAMES is set to 1 then Ethernet frames
+ * that are not in Ethernet II format will be dropped.  This option is included for
+ * potential future IP stack developments. */
+#define ipconfigFILTER_OUT_NON_ETHERNET_II_FRAMES             1
+
+/* If ipconfigETHERNET_DRIVER_FILTERS_FRAME_TYPES is set to 1 then it is the
+ * responsibility of the Ethernet interface to filter out packets that are of no
+ * interest.  If the Ethernet interface does not implement this functionality, then
+ * set ipconfigETHERNET_DRIVER_FILTERS_FRAME_TYPES to 0 to have the IP stack
+ * perform the filtering instead (it is much less efficient for the stack to do it
+ * because the packet will already have been passed into the stack).  If the
+ * Ethernet driver does all the necessary filtering in hardware then software
+ * filtering can be removed by using a value other than 1 or 0. */
+#define ipconfigETHERNET_DRIVER_FILTERS_FRAME_TYPES           1
+
+/* The windows simulator cannot really simulate MAC interrupts, and needs to
+ * block occasionally to allow other tasks to run. */
+#define configWINDOWS_MAC_INTERRUPT_SIMULATOR_DELAY           ( 20 / portTICK_PERIOD_MS )
+
+/* Advanced only: in order to access 32-bit fields in the IP packets with
+ * 32-bit memory instructions, all packets will be stored 32-bit-aligned, plus 16-bits.
+ * This has to do with the contents of the IP-packets: all 32-bit fields are
+ * 32-bit-aligned, plus 16-bit(!) */
+#define ipconfigPACKET_FILLER_SIZE                            2
+
+/* Define the size of the pool of TCP window descriptors.  On the average, each
+ * TCP socket will use up to 2 x 6 descriptors, meaning that it can have 2 x 6
+ * outstanding packets (for Rx and Tx).  When using up to 10 TP sockets
+ * simultaneously, one could define TCP_WIN_SEG_COUNT as 120. */
+#define ipconfigTCP_WIN_SEG_COUNT                             240
+
+/* Each TCP socket has a circular buffers for Rx and Tx, which have a fixed
+ * maximum size.  Define the size of Rx buffer for TCP sockets. */
+#define ipconfigTCP_RX_BUFFER_LENGTH                          ( 1000 )
+
+/* Define the size of Tx buffer for TCP sockets. */
+#define ipconfigTCP_TX_BUFFER_LENGTH                          ( 1000 )
+
+/* When using call-back handlers, the driver may check if the handler points to
+ * real program memory (RAM or flash) or just has a random non-zero value. */
+#define ipconfigIS_VALID_PROG_ADDRESS( x )    ( ( x ) != NULL )
+
+/* Include support for TCP hang protection.  All sockets in a connecting or
+ * disconnecting stage will timeout after a period of non-activity. */
+#define ipconfigTCP_HANG_PROTECTION         ( 1 )
+#define ipconfigTCP_HANG_PROTECTION_TIME    ( 30 )
+
+/* Include support for TCP keep-alive messages. */
+#define ipconfigTCP_KEEP_ALIVE              ( 1 )
+#define ipconfigTCP_KEEP_ALIVE_INTERVAL     ( 20 ) /* in seconds */
+
+#define portINLINE                          __inline
+
+#endif /* FREERTOS_IP_CONFIG_H */
diff --git a/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/WIN32.vcxproj b/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/WIN32.vcxproj
new file mode 100644
index 000000000..602de1d0f
--- /dev/null
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@@ -0,0 +1,207 @@
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+    <ClInclude Include="..\..\..\FreeRTOS-Plus\Source\FreeRTOS-Plus-TCP\include\NetworkBufferManagement.h" />
+    <ClInclude Include="..\..\..\FreeRTOS-Plus\Source\FreeRTOS-Plus-TCP\include\NetworkInterface.h" />
+    <ClInclude Include="..\..\..\FreeRTOS-Plus\Source\Utilities\logging\logging.h" />
+    <ClInclude Include="..\..\..\FreeRTOS-Plus\Source\Utilities\logging\logging_levels.h" />
+    <ClInclude Include="..\..\..\FreeRTOS-Plus\Source\Utilities\logging\logging_stack.h" />
+    <ClInclude Include="..\..\Source\Application-Protocols\coreSNTP\source\include\core_sntp_config_defaults.h" />
+    <ClInclude Include="..\..\Source\FreeRTOS-Plus-TCP\include\FreeRTOS_errno_TCP.h" />
+    <ClInclude Include="..\..\Source\Application-Protocols\coreSNTP\source\include\core_sntp_serializer.h" />
+    <ClInclude Include="..\..\Source\Application-Protocols\coreSNTP\source\include\core_sntp_client.h" />
+    <ClInclude Include="demo_config.h" />
+    <ClInclude Include="common_demo_include.h" />
+    <ClInclude Include="FreeRTOSConfig.h" />
+    <ClInclude Include="FreeRTOSIPConfig.h" />
+    <ClInclude Include="core_sntp_config.h" />
+  </ItemGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
+  <ImportGroup Label="ExtensionTargets">
+  </ImportGroup>
+</Project>
\ No newline at end of file
diff --git a/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/WIN32.vcxproj.filters b/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/WIN32.vcxproj.filters
new file mode 100644
index 000000000..1e7f6386e
--- /dev/null
+++ b/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/WIN32.vcxproj.filters
@@ -0,0 +1,247 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup>
+    <Filter Include="FreeRTOS">
+      <UniqueIdentifier>{af3445a1-4908-4170-89ed-39345d90d30c}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="FreeRTOS\Source">
+      <UniqueIdentifier>{f32be356-4763-4cae-9020-974a2638cb08}</UniqueIdentifier>
+      <Extensions>*.c</Extensions>
+    </Filter>
+    <Filter Include="FreeRTOS\Source\Portable">
+      <UniqueIdentifier>{88f409e6-d396-4ac5-94bd-7a99c914be46}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="FreeRTOS+">
+      <UniqueIdentifier>{e5ad4ec7-23dc-4295-8add-2acaee488f5a}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="FreeRTOS\Source\include">
+      <UniqueIdentifier>{d2dcd641-8d91-492b-852f-5563ffadaec6}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="FreeRTOS+\FreeRTOS+TCP">
+      <UniqueIdentifier>{8672fa26-b119-481f-8b8d-086419c01a3e}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="FreeRTOS+\FreeRTOS+TCP\portable">
+      <UniqueIdentifier>{4570be11-ec96-4b55-ac58-24b50ada980a}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="FreeRTOS+\FreeRTOS+TCP\include">
+      <UniqueIdentifier>{5d93ed51-023a-41ad-9243-8d230165d34b}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="DemoTasks">
+      <UniqueIdentifier>{b71e974a-9f28-4815-972b-d930ba8a34d0}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="FreeRTOS+\FreeRTOS IoT Libraries">
+      <UniqueIdentifier>{60717407-397f-4ea5-8492-3314acdd25f0}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="FreeRTOS+\FreeRTOS IoT Libraries\standard">
+      <UniqueIdentifier>{8a90222f-d723-4b4e-8e6e-c57afaf7fa92}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="FreeRTOS+\FreeRTOS IoT Libraries\standard\coreSNTP">
+      <UniqueIdentifier>{2d17d5e6-ed70-4e42-9693-f7a63baf4948}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="FreeRTOS+\FreeRTOS IoT Libraries\standard\coreSNTP\include">
+      <UniqueIdentifier>{6ad56e6d-c330-4830-8f4b-c75b05dfa866}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="FreeRTOS+\FreeRTOS IoT Libraries\platform">
+      <UniqueIdentifier>{84613aa2-91dc-4e1a-a3b3-823b6d7bf0e0}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="FreeRTOS+\FreeRTOS IoT Libraries\platform\backoff_algorithm">
+      <UniqueIdentifier>{70524181-23e5-4dde-a3fb-6afc11d6df04}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="FreeRTOS+\FreeRTOS IoT Libraries\platform\backoff_algorithm\include">
+      <UniqueIdentifier>{6e7ee4cd-b54c-4f67-9b70-8c1e9fe80b92}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="FreeRTOS+\FreeRTOS IoT Libraries\platform\logging">
+      <UniqueIdentifier>{59d75faa-e4df-4d85-bf56-67e9cc801004}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="FreeRTOS+\FreeRTOS IoT Libraries\platform\transport">
+      <UniqueIdentifier>{212f58ea-e09c-4778-9935-31b4e95538ee}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="FreeRTOS+\FreeRTOS IoT Libraries\platform\transport\include">
+      <UniqueIdentifier>{2e22b7fe-a180-47a1-b459-6a3451c7a4ee}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="Config">
+      <UniqueIdentifier>{1407130d-da4c-4bcc-8ca0-4cf77f4cf97f}</UniqueIdentifier>
+    </Filter>
+  </ItemGroup>
+  <ItemGroup>
+    <ClCompile Include="..\..\..\FreeRTOS\Source\portable\MSVC-MingW\port.c">
+      <Filter>FreeRTOS\Source\Portable</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\FreeRTOS\Source\timers.c">
+      <Filter>FreeRTOS\Source</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\FreeRTOS\Source\list.c">
+      <Filter>FreeRTOS\Source</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\FreeRTOS\Source\queue.c">
+      <Filter>FreeRTOS\Source</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\FreeRTOS\Source\tasks.c">
+      <Filter>FreeRTOS\Source</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\FreeRTOS-Plus\Source\FreeRTOS-Plus-TCP\FreeRTOS_UDP_IP.c">
+      <Filter>FreeRTOS+\FreeRTOS+TCP</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\FreeRTOS-Plus\Source\FreeRTOS-Plus-TCP\FreeRTOS_DHCP.c">
+      <Filter>FreeRTOS+\FreeRTOS+TCP</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\FreeRTOS-Plus\Source\FreeRTOS-Plus-TCP\FreeRTOS_DNS.c">
+      <Filter>FreeRTOS+\FreeRTOS+TCP</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\FreeRTOS-Plus\Source\FreeRTOS-Plus-TCP\FreeRTOS_Sockets.c">
+      <Filter>FreeRTOS+\FreeRTOS+TCP</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\FreeRTOS-Plus\Source\FreeRTOS-Plus-TCP\portable\BufferManagement\BufferAllocation_2.c">
+      <Filter>FreeRTOS+\FreeRTOS+TCP\portable</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\FreeRTOS-Plus\Source\FreeRTOS-Plus-TCP\portable\NetworkInterface\WinPCap\NetworkInterface.c">
+      <Filter>FreeRTOS+\FreeRTOS+TCP\portable</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\FreeRTOS-Plus\Source\FreeRTOS-Plus-TCP\FreeRTOS_ARP.c">
+      <Filter>FreeRTOS+\FreeRTOS+TCP</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\FreeRTOS-Plus\Source\FreeRTOS-Plus-TCP\FreeRTOS_IP.c">
+      <Filter>FreeRTOS+\FreeRTOS+TCP</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\FreeRTOS-Plus\Source\FreeRTOS-Plus-TCP\FreeRTOS_TCP_IP.c">
+      <Filter>FreeRTOS+\FreeRTOS+TCP</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\FreeRTOS-Plus\Source\FreeRTOS-Plus-TCP\FreeRTOS_TCP_WIN.c">
+      <Filter>FreeRTOS+\FreeRTOS+TCP</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\FreeRTOS\Source\event_groups.c">
+      <Filter>FreeRTOS\Source</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\FreeRTOS\Source\portable\MemMang\heap_4.c">
+      <Filter>FreeRTOS\Source\Portable</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\FreeRTOS-Plus\Source\FreeRTOS-Plus-TCP\FreeRTOS_Stream_Buffer.c">
+      <Filter>FreeRTOS+\FreeRTOS+TCP</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\FreeRTOS\Source\stream_buffer.c">
+      <Filter>FreeRTOS\Source</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\FreeRTOS-Plus\Demo\Common\Logging\windows\Logging_WinSim.c" />
+    <ClCompile Include="..\Common\main.c" />
+    <ClCompile Include="DemoTasks\SNTPClientTask.c">
+    <ClCompile Include="DemoTasks\SampleAppTask.c">
+      <Filter>DemoTasks</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\Source\Application-Protocols\coreSNTP\source\core_sntp_client.c">
+      <Filter>FreeRTOS+\FreeRTOS IoT Libraries\standard\coreSNTP</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\..\Source\Application-Protocols\coreSNTP\source\core_sntp_serializer.c">
+      <Filter>FreeRTOS+\FreeRTOS IoT Libraries\standard\coreSNTP</Filter>
+    </ClCompile>
+  </ItemGroup>
+  <ItemGroup>
+    <ClInclude Include="..\..\..\FreeRTOS-Plus\Source\FreeRTOS-Plus-TCP\include\NetworkInterface.h">
+      <Filter>FreeRTOS+\FreeRTOS+TCP\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\FreeRTOS-Plus\Source\FreeRTOS-Plus-TCP\include\FreeRTOS_DNS.h">
+      <Filter>FreeRTOS+\FreeRTOS+TCP\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\FreeRTOS-Plus\Source\FreeRTOS-Plus-TCP\include\FreeRTOS_Sockets.h">
+      <Filter>FreeRTOS+\FreeRTOS+TCP\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\FreeRTOS-Plus\Source\FreeRTOS-Plus-TCP\include\FreeRTOS_UDP_IP.h">
+      <Filter>FreeRTOS+\FreeRTOS+TCP\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\FreeRTOS\Source\include\timers.h">
+      <Filter>FreeRTOS\Source\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\FreeRTOS\Source\include\event_groups.h">
+      <Filter>FreeRTOS\Source\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\FreeRTOS\Source\include\FreeRTOS.h">
+      <Filter>FreeRTOS\Source\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\FreeRTOS\Source\include\queue.h">
+      <Filter>FreeRTOS\Source\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\FreeRTOS\Source\include\semphr.h">
+      <Filter>FreeRTOS\Source\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\FreeRTOS\Source\include\task.h">
+      <Filter>FreeRTOS\Source\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\FreeRTOS\Source\portable\MSVC-MingW\portmacro.h">
+      <Filter>FreeRTOS\Source\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\FreeRTOS-Plus\Source\FreeRTOS-Plus-TCP\include\FreeRTOS_IP_Private.h">
+      <Filter>FreeRTOS+\FreeRTOS+TCP\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\FreeRTOS-Plus\Source\FreeRTOS-Plus-TCP\include\NetworkBufferManagement.h">
+      <Filter>FreeRTOS+\FreeRTOS+TCP\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\FreeRTOS-Plus\Source\FreeRTOS-Plus-TCP\include\FreeRTOS_ARP.h">
+      <Filter>FreeRTOS+\FreeRTOS+TCP\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\FreeRTOS-Plus\Source\FreeRTOS-Plus-TCP\include\FreeRTOS_DHCP.h">
+      <Filter>FreeRTOS+\FreeRTOS+TCP\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\FreeRTOS-Plus\Source\FreeRTOS-Plus-TCP\include\FreeRTOS_IP.h">
+      <Filter>FreeRTOS+\FreeRTOS+TCP\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\FreeRTOS-Plus\Source\FreeRTOS-Plus-TCP\include\FreeRTOS_TCP_IP.h">
+      <Filter>FreeRTOS+\FreeRTOS+TCP\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\FreeRTOS-Plus\Source\FreeRTOS-Plus-TCP\include\FreeRTOS_TCP_WIN.h">
+      <Filter>FreeRTOS+\FreeRTOS+TCP\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\FreeRTOS-Plus\Source\FreeRTOS-Plus-TCP\include\FreeRTOSIPConfigDefaults.h">
+      <Filter>FreeRTOS+\FreeRTOS+TCP\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\FreeRTOS-Plus\Source\FreeRTOS-Plus-TCP\include\IPTraceMacroDefaults.h">
+      <Filter>FreeRTOS+\FreeRTOS+TCP\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\FreeRTOS-Plus\Source\FreeRTOS-Plus-TCP\include\FreeRTOS_Stream_Buffer.h">
+      <Filter>FreeRTOS+\FreeRTOS+TCP\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\FreeRTOS\Source\include\portable.h">
+      <Filter>FreeRTOS\Source\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\FreeRTOS\Source\include\projdefs.h">
+      <Filter>FreeRTOS\Source\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\Source\Application-Protocols\coreSNTP\source\include\core_sntp_serializer.h">
+      <Filter>FreeRTOS+\FreeRTOS IoT Libraries\standard\coreSNTP\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\Source\Application-Protocols\coreSNTP\source\include\core_sntp_client.h">
+      <Filter>FreeRTOS+\FreeRTOS IoT Libraries\standard\coreSNTP\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\Source\FreeRTOS-Plus-TCP\include\FreeRTOS_errno_TCP.h">
+      <Filter>FreeRTOS+\FreeRTOS+TCP\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\Source\Application-Protocols\coreSNTP\source\include\core_sntp_config_defaults.h">
+      <Filter>FreeRTOS+\FreeRTOS IoT Libraries\standard\coreSNTP\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\Source\Utilities\backoff_algorithm\source\include\backoff_algorithm.h">
+      <Filter>FreeRTOS+\FreeRTOS IoT Libraries\platform\backoff_algorithm\include</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\FreeRTOS-Plus\Source\Utilities\logging\logging.h">
+      <Filter>FreeRTOS+\FreeRTOS IoT Libraries\platform\logging</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\FreeRTOS-Plus\Source\Utilities\logging\logging_levels.h">
+      <Filter>FreeRTOS+\FreeRTOS IoT Libraries\platform\logging</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\..\FreeRTOS-Plus\Source\Utilities\logging\logging_stack.h">
+      <Filter>FreeRTOS+\FreeRTOS IoT Libraries\platform\logging</Filter>
+    </ClInclude>
+    <ClInclude Include="FreeRTOSConfig.h">
+      <Filter>Config</Filter>
+    </ClInclude>
+    <ClInclude Include="FreeRTOSIPConfig.h">
+      <Filter>Config</Filter>
+    </ClInclude>
+    <ClInclude Include="core_sntp_config.h">
+      <Filter>Config</Filter>
+    </ClInclude>
+    <ClInclude Include="demo_config.h">
+      <Filter>Config</Filter>
+    </ClInclude>
+    <ClInclude Include="common_demo_include.h">
+      <Filter>Config</Filter>
+    </ClInclude>
+  </ItemGroup>
+</Project>
\ No newline at end of file
diff --git a/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/common_demo_include.h b/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/common_demo_include.h
new file mode 100755
index 000000000..cfcae950f
--- /dev/null
+++ b/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/common_demo_include.h
@@ -0,0 +1,98 @@
+/*
+ * FreeRTOS V202104.00
+ * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+ * the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * http://www.FreeRTOS.org
+ * http://aws.amazon.com/freertos
+ */
+#ifndef COMMON_DEMO_INCLUDE_H
+#define COMMON_DEMO_INCLUDE_H
+
+#include "demo_config.h"
+
+/**
+ * @brief Utility macro to convert milliseconds to the fractions value of an SNTP timestamp.
+ * @note The fractions value MUST be less than 1000 as duration of seconds is not represented
+ * as fractions part of SNTP timestamp.
+ */
+#define MILLISECONDS_TO_SNTP_FRACTIONS( ms )    ( ms * 1000 * SNTP_FRACTION_VALUE_PER_MICROSECOND )
+
+/**
+ * @brief Type representing system time in Coordinated Universal Time (UTC)
+ * zone as time since 1st January 1970 00h:00m:00s.
+ *
+ * @note This demo uses RAM-based mathematical model to represent UTC time
+ * in system.
+ */
+typedef struct UTCTime
+{
+    uint32_t secs;
+    uint32_t msecs;
+} UTCTime_t;
+
+/**
+ * @brief Utility function to print the system time as both UNIX time (i.e.
+ * time since 1st January 1970 00h:00m:00s) and human-readable time (in the
+ * YYYY-MM-DD dd:mm:ss format).
+ *
+ * @param[in] pTime The system time to be printed.
+ */
+void printTime( const UTCTime_t * pTime );
+
+/**
+ * @brief Initializes the system clock with the first second of the year (i.e. at midnight
+ * of 1st January) that is configured in the democonfigSYSTEM_START_YEAR config of
+ * demo_config.h file.
+ */
+void initializeSystemClock( void );
+
+/**
+ * @brief The demo function for an application to query wall-clock
+ * time as Coordinated Universal Time (UTC) from the system.
+ *
+ * @note This demo showcases a RAM-based mathematical model for
+ * representing current UTC time in the system.
+ *
+ * @param[out] pTime This will be populated with the current time
+ * in the system as total time since 1st January 1900 00h:00m:00s.
+ */
+void systemGetWallClockTime( UTCTime_t * pTime );
+
+/**
+ * @brief The task function for a sample application that queries
+ * system time periodically.
+ */
+void sampleAppTask( void * pvParameters );
+
+/**
+ * @brief The task function that represents a daemon SNTP client task
+ * that is responsible for periodically synchronizing system time with
+ * time servers from the list of configured time servers in
+ * democonfigLIST_OF_TIME_SERVERS.
+ *
+ * @note The usage of the coreSNTP library API is encapsulated within
+ * this task. The rest of the FreeRTOS tasks/application does not need
+ * to be aware of the SNTP client as they can query time from the
+ * @ref systemGetWallClockTime() function.
+ */
+void sntpTask( void * parameters );
+
+
+#endif /* ifndef COMMON_DEMO_INCLUDE_H */
diff --git a/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/core_sntp_config.h b/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/core_sntp_config.h
new file mode 100755
index 000000000..40f9e15ec
--- /dev/null
+++ b/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/core_sntp_config.h
@@ -0,0 +1,66 @@
+/*
+ * FreeRTOS V202104.00
+ * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+ * the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * http://www.FreeRTOS.org
+ * http://aws.amazon.com/freertos
+ */
+#ifndef CORE_SNTP_CONFIG_H
+#define CORE_SNTP_CONFIG_H
+
+/**************************************************/
+/******* DO NOT CHANGE the following order ********/
+/**************************************************/
+
+/* Include logging header files and define logging macros in the following order:
+ * 1. Include the header file "logging_levels.h".
+ * 2. Define the LIBRARY_LOG_NAME and LIBRARY_LOG_LEVEL macros depending on
+ * the logging configuration for SNTP.
+ * 3. Include the header file "logging_stack.h", if logging is enabled for SNTP.
+ */
+
+#include "logging_levels.h"
+
+/* Logging configuration for the SNTP library. */
+#ifndef LIBRARY_LOG_NAME
+    #define LIBRARY_LOG_NAME    "SNTP"
+#endif
+
+#ifndef LIBRARY_LOG_LEVEL
+    #define LIBRARY_LOG_LEVEL    LOG_ERROR
+#endif
+
+/* Prototype for the function used to print to console on Windows simulator
+ * of FreeRTOS.
+ * The function prints to the console before the network is connected;
+ * then a UDP port after the network has connected. */
+extern void vLoggingPrintf( const char * pcFormatString,
+                            ... );
+
+/* Map the SdkLog macro to the logging function to enable logging
+ * on Windows simulator. */
+#ifndef SdkLog
+    #define SdkLog( message )    vLoggingPrintf message
+#endif
+
+#include "logging_stack.h"
+/************ End of logging configuration ****************/
+
+#endif /* ifndef CORE_SNTP_CONFIG_H */
diff --git a/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/core_sntp_demo.sln b/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/core_sntp_demo.sln
new file mode 100644
index 000000000..dcfc1fe09
--- /dev/null
+++ b/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/core_sntp_demo.sln
@@ -0,0 +1,25 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 16
+VisualStudioVersion = 16.0.29215.179
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "RTOSDemo", "WIN32.vcxproj", "{C686325E-3261-42F7-AEB1-DDE5280E1CEB}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Win32 = Debug|Win32
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{C686325E-3261-42F7-AEB1-DDE5280E1CEB}.Debug|Win32.ActiveCfg = Debug|Win32
+		{C686325E-3261-42F7-AEB1-DDE5280E1CEB}.Debug|Win32.Build.0 = Debug|Win32
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {150F08BF-9D61-4CC2-8DBF-1335172A1EA4}
+	EndGlobalSection
+	GlobalSection(TestCaseManagementSettings) = postSolution
+		CategoryFile = FreeRTOS_Plus_TCP_Minimal.vsmdi
+	EndGlobalSection
+EndGlobal
diff --git a/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/demo_config.h b/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/demo_config.h
new file mode 100755
index 000000000..75fbd1418
--- /dev/null
+++ b/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/demo_config.h
@@ -0,0 +1,128 @@
+/*
+ * FreeRTOS V202104.00
+ * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+ * the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * http://www.FreeRTOS.org
+ * http://aws.amazon.com/freertos
+ *
+ * 1 tab == 4 spaces!
+ */
+
+#ifndef DEMO_CONFIG_H
+#define DEMO_CONFIG_H
+
+/**************************************************/
+/******* DO NOT CHANGE the following order ********/
+/**************************************************/
+
+/* Include logging header files and define logging macros in the following order:
+ * 1. Include the header file "logging_levels.h".
+ * 2. Define the LIBRARY_LOG_NAME and LIBRARY_LOG_LEVEL macros depending on
+ * the logging configuration for DEMO.
+ * 3. Include the header file "logging_stack.h", if logging is enabled for DEMO.
+ */
+
+#include "logging_levels.h"
+
+/* Logging configuration for the Demo. */
+#ifndef LIBRARY_LOG_NAME
+    #define LIBRARY_LOG_NAME    "SNTPDemo"
+#endif
+
+#ifndef LIBRARY_LOG_LEVEL
+    #define LIBRARY_LOG_LEVEL    LOG_INFO
+#endif
+
+/* Prototype for the function used to print to console on Windows simulator
+ * of FreeRTOS.
+ * The function prints to the console before the network is connected;
+ * then a UDP port after the network has connected. */
+extern void vLoggingPrintf( const char * pcFormatString,
+                            ... );
+
+/* Map the SdkLog macro to the logging function to enable logging
+ * on Windows simulator. */
+#ifndef SdkLog
+    #define SdkLog( message )    vLoggingPrintf message
+#endif
+
+#include "logging_stack.h"
+
+/************ End of logging configuration ****************/
+
+/**
+ * @brief The desired accuracy (in milliseconds) of system clock in relation with internet time.
+ * In other words, this is the maximum tolerance desired for clock drift in the system.
+ */
+#define democonfigDESIRED_CLOCK_ACCURACY_MS     ( 1000 )
+
+/**
+ * @brief The system clock tolerance (in parts per million) that represents the rate of clock
+ * drift of the system. The rate can be viewed as the system clock drift that occurs as milliseconds
+ * per second.
+ *
+ * @note In systems with a HW oscillator based clock, the frequency tolerance can be obtained from the
+ * hardware specification of the clock oscillator.
+ * @note This demo DOES NOT use a hardware clock oscillator as it runs on Windows Simulator. The configuration
+ * ONLY provides the user to view the impact of the settings for "Clock Tolerance" and "Desired
+ * Clock Accuracy" configurations on the calculated "SNTP polling period".
+ */
+#define democonfigSYSTEM_CLOCK_TOLERANCE_PPM    ( 32000 )
+
+/**
+ * @brief The set of time servers, in decreasing order of priority, for configuring the SNTP client.
+ * The servers SHOULD be listed as comma-separated list of strings. For example, the following
+ * can be a configuration used:
+ */
+#define democonfigLIST_OF_TIME_SERVERS          "time.cloudflare.com", "pool.ntp.org"
+
+/**
+ * @brief The year to bake in the demo application for initializing the system clock with.
+ * The demo initializes the system clock time for the starting second of the 1st January of
+ * the configured year. So for example, with a configuration of year 2021, the demo will
+ * initialize the system clock time as 1st January 2021 00h:00m:00s.
+ *
+ * @note The coreSNTP library REQUIRES that the client system time is within ~68 years of internet
+ * time. Thus, for systems that do not have an Real-Time Clock module, this demo shows how
+ * a starting time can be baked in the device firmware to keep the starting time of the system
+ * close to actual time on the first boot-up of device.
+ * For such systems without Real-Time Clock module, all device boot ups from subsequent device resets
+ * or power cycles can continue to carry close to correct time by EITHER
+ *  * (RECOMMENDED) Saving the most recent time in non-volatile memory
+ *     OR
+ *  * Using the same firmware baked-in starting time of device for every boot-up.
+ */
+#define democonfigSYSTEM_START_YEAR             ( 2021 )
+
+/**
+ * @brief The timeout (in milliseconds) for the time response to a time request made to a
+ * time server.
+ */
+#define democonfigSERVER_RESPONSE_TIMEOUT_MS    ( 5000 )
+
+/**
+ * @brief Set the stack size of the main demo task.
+ *
+ * In the Windows port, this stack only holds a structure. The actual
+ * stack is created by an operating system thread.
+ */
+#define democonfigDEMO_STACKSIZE                configMINIMAL_STACK_SIZE
+
+#endif /* DEMO_CONFIG_H */
diff --git a/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/main.c b/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/main.c
new file mode 100755
index 000000000..7a8a666e0
--- /dev/null
+++ b/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/main.c
@@ -0,0 +1,412 @@
+/*
+ * FreeRTOS V202104.00
+ * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+ * the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * https://www.FreeRTOS.org
+ * https://github.com/FreeRTOS
+ *
+ */
+
+/***
+ * See https://www.FreeRTOS.org/coresntp for configuration and usage instructions,
+ ***/
+
+/* Standard includes. */
+#include <stdio.h>
+#include <time.h>
+
+/* Visual studio intrinsics used so the __debugbreak() function is available
+ * should an assert get hit. */
+#include <intrin.h>
+
+/* FreeRTOS includes. */
+#include <FreeRTOS.h>
+#include "task.h"
+
+/* TCP/IP stack includes. */
+#include "FreeRTOS_IP.h"
+#include "FreeRTOS_Sockets.h"
+
+/* Demo logging includes. */
+#include "logging.h"
+
+/* Demo Specific configs. */
+#include "demo_config.h"
+#include "common_demo_include.h"
+
+/*
+ * Prototypes for the demos that can be started from this project.  Note the
+ * SNTP demo is not actually started until the network is already, which is
+ * indicated by vApplicationIPNetworkEventHook() executing - hence
+ * prvStartSimpleSNTPDemo() is called from inside vApplicationIPNetworkEventHook().
+ */
+static void vStartSntpDemo( void );
+
+/*
+ * Just seeds the simple pseudo random number generator.
+ *
+ * !!! NOTE !!!
+ * This is not a secure method of generating random numbers and production
+ * devices should use a true random number generator (TRNG).
+ */
+static void prvSRand( UBaseType_t ulSeed );
+
+/*
+ * Miscellaneous initialization including preparing the logging and seeding the
+ * random number generator.
+ */
+static void prvMiscInitialisation( void );
+
+/* The default IP and MAC address used by the demo.  The address configuration
+ * defined here will be used if ipconfigUSE_DHCP is 0, or if ipconfigUSE_DHCP is
+ * 1 but a DHCP server could not be contacted.  See the online documentation for
+ * more information. */
+static const uint8_t ucIPAddress[ 4 ] = { configIP_ADDR0, configIP_ADDR1, configIP_ADDR2, configIP_ADDR3 };
+static const uint8_t ucNetMask[ 4 ] = { configNET_MASK0, configNET_MASK1, configNET_MASK2, configNET_MASK3 };
+static const uint8_t ucGatewayAddress[ 4 ] = { configGATEWAY_ADDR0, configGATEWAY_ADDR1, configGATEWAY_ADDR2, configGATEWAY_ADDR3 };
+static const uint8_t ucDNSServerAddress[ 4 ] = { configDNS_SERVER_ADDR0, configDNS_SERVER_ADDR1, configDNS_SERVER_ADDR2, configDNS_SERVER_ADDR3 };
+
+/* Set the following constant to pdTRUE to log using the method indicated by the
+ * name of the constant, or pdFALSE to not log using the method indicated by the
+ * name of the constant.  Options include to standard out (xLogToStdout), to a disk
+ * file (xLogToFile), and to a UDP port (xLogToUDP).  If xLogToUDP is set to pdTRUE
+ * then UDP messages are sent to the IP address configured as the UDP logging server
+ * address (see the configUDP_LOGGING_ADDR0 definitions in FreeRTOSConfig.h) and
+ * the port number set by configPRINT_PORT in FreeRTOSConfig.h. */
+const BaseType_t xLogToStdout = pdTRUE, xLogToFile = pdFALSE, xLogToUDP = pdFALSE;
+
+/* Default MAC address configuration.  The demo creates a virtual network
+ * connection that uses this MAC address by accessing the raw Ethernet data
+ * to and from a real network connection on the host PC.  See the
+ * configNETWORK_INTERFACE_TO_USE definition for information on how to configure
+ * the real network connection to use. */
+const uint8_t ucMACAddress[ 6 ] = { configMAC_ADDR0, configMAC_ADDR1, configMAC_ADDR2, configMAC_ADDR3, configMAC_ADDR4, configMAC_ADDR5 };
+
+/* Use by the pseudo random number generator. */
+static UBaseType_t ulNextRand;
+/*-----------------------------------------------------------*/
+
+int main( void )
+{
+    /***
+     * See https://www.FreeRTOS.org/coresntp for configuration and usage instructions.
+     *
+     ***/
+
+    /* Miscellaneous initialization including preparing the logging and seeding
+     * the random number generator. */
+    prvMiscInitialisation();
+
+    /* Initialize the network interface.
+     *
+     ***NOTE*** Tasks that use the network are created in the network event hook
+     * when the network is connected and ready for use (see the implementation of
+     * vApplicationIPNetworkEventHook() below).  The address values passed in here
+     * are used if ipconfigUSE_DHCP is set to 0, or if ipconfigUSE_DHCP is set to 1
+     * but a DHCP server cannot be contacted. */
+    FreeRTOS_IPInit( ucIPAddress, ucNetMask, ucGatewayAddress, ucDNSServerAddress, ucMACAddress );
+
+    /* Start the RTOS scheduler. */
+    vTaskStartScheduler();
+
+    /* If all is well, the scheduler will now be running, and the following
+     * line will never be reached.  If the following line does execute, then
+     * there was insufficient FreeRTOS heap memory available for the idle and/or
+     * timer tasks to be created.  See the memory management section on the
+     * FreeRTOS web site for more details (this is standard text that is not
+     * really applicable to the Win32 simulator port). */
+    for( ; ; )
+    {
+        __debugbreak();
+    }
+}
+/*-----------------------------------------------------------*/
+
+/**
+ * @brief Entry point of the demo that creates 2 tasks:
+ * 1. One task represents the SNTP client that periodically synchronizes system time with
+ * time from time servers.
+ * 2. The other task represents a sample application time that queries the system time
+ * periodically and prints it in human readable form of the YYYY-MM-DD hh:mm:ss.
+ */
+void vStartSntpDemo( void )
+{
+    initializeSystemClock();
+
+    /* Create the SNTP client task that is responsible for synchronizing system time with the time servers
+     * periodically. This is created as a high priority task to keep the SNTP client operation unhindered. */
+    xTaskCreate( sntpTask,                 /* Function that implements the task. */
+                 "SntpClientTask",         /* Text name for the task - only used for debugging. */
+                 democonfigDEMO_STACKSIZE, /* Size of stack (in words, not bytes) to allocate for the task. */
+                 NULL,                     /* Task parameter - not used in this case. */
+                 configMAX_PRIORITIES - 1, /* Task priority, must be between 0 and configMAX_PRIORITIES - 1. */
+                 NULL );
+
+    /* Create the task that represents an application needing wall-clock time. */
+    xTaskCreate( sampleAppTask,            /* Function that implements the task. */
+                 "SampleAppTask",              /* Text name for the task - only used for debugging. */
+                 democonfigDEMO_STACKSIZE, /* Size of stack (in words, not bytes) to allocate for the task. */
+                 NULL,                     /* Task parameter - not used in this case. */
+                 tskIDLE_PRIORITY,         /* Task priority, must be between 0 and configMAX_PRIORITIES - 1. */
+                 NULL );                   /* Used to pass out a handle to the created task - not used in this case. */
+}
+
+/*-----------------------------------------------------------*/
+
+/* Called by FreeRTOS+TCP when the network connects or disconnects.  Disconnect
+ * events are only received if implemented in the MAC driver. */
+void vApplicationIPNetworkEventHook( eIPCallbackEvent_t eNetworkEvent )
+{
+    uint32_t ulIPAddress, ulNetMask, ulGatewayAddress, ulDNSServerAddress;
+    char cBuffer[ 16 ];
+    static BaseType_t xTasksAlreadyCreated = pdFALSE;
+
+    /* If the network has just come up...*/
+    if( eNetworkEvent == eNetworkUp )
+    {
+        /* Create the tasks that use the IP stack if they have not already been
+         * created. */
+        if( xTasksAlreadyCreated == pdFALSE )
+        {
+            /* Demos that use the network are created after the network is
+             * up. */
+            LogInfo( ( "---------STARTING DEMO---------\r\n" ) );
+            vStartSntpDemo();
+            xTasksAlreadyCreated = pdTRUE;
+        }
+
+        /* Print out the network configuration, which may have come from a DHCP
+         * server. */
+        FreeRTOS_GetAddressConfiguration( &ulIPAddress, &ulNetMask, &ulGatewayAddress, &ulDNSServerAddress );
+        FreeRTOS_inet_ntoa( ulIPAddress, cBuffer );
+        LogInfo( ( "\r\n\r\nIP Address: %s\r\n", cBuffer ) );
+
+        FreeRTOS_inet_ntoa( ulNetMask, cBuffer );
+        LogInfo( ( "Subnet Mask: %s\r\n", cBuffer ) );
+
+        FreeRTOS_inet_ntoa( ulGatewayAddress, cBuffer );
+        LogInfo( ( "Gateway Address: %s\r\n", cBuffer ) );
+
+        FreeRTOS_inet_ntoa( ulDNSServerAddress, cBuffer );
+        LogInfo( ( "DNS Server Address: %s\r\n\r\n\r\n", cBuffer ) );
+    }
+}
+/*-----------------------------------------------------------*/
+
+void vAssertCalled( const char * pcFile,
+                    uint32_t ulLine )
+{
+    volatile uint32_t ulBlockVariable = 0UL;
+    volatile char * pcFileName = ( volatile char * ) pcFile;
+    volatile uint32_t ulLineNumber = ulLine;
+
+    ( void ) pcFileName;
+    ( void ) ulLineNumber;
+
+    printf( "vAssertCalled( %s, %u\n", pcFile, ulLine );
+
+    /* Setting ulBlockVariable to a non-zero value in the debugger will allow
+     * this function to be exited. */
+    taskDISABLE_INTERRUPTS();
+    {
+        while( ulBlockVariable == 0UL )
+        {
+            __debugbreak();
+        }
+    }
+    taskENABLE_INTERRUPTS();
+}
+/*-----------------------------------------------------------*/
+
+UBaseType_t uxRand( void )
+{
+    const uint32_t ulMultiplier = 0x015a4e35UL, ulIncrement = 1UL;
+
+    /*
+     * Utility function to generate a pseudo random number.
+     *
+     * !!!NOTE!!!
+     * This is not a secure method of generating a random number.  Production
+     * devices should use a True Random Number Generator (TRNG).
+     */
+    ulNextRand = ( ulMultiplier * ulNextRand ) + ulIncrement;
+    return( ( int ) ( ulNextRand >> 16UL ) & 0x7fffUL );
+}
+/*-----------------------------------------------------------*/
+
+static void prvSRand( UBaseType_t ulSeed )
+{
+    /* Utility function to seed the pseudo random number generator. */
+    ulNextRand = ulSeed;
+}
+/*-----------------------------------------------------------*/
+
+static void prvMiscInitialisation( void )
+{
+    time_t xTimeNow;
+    uint32_t ulLoggingIPAddress;
+
+    ulLoggingIPAddress = FreeRTOS_inet_addr_quick( configUDP_LOGGING_ADDR0, configUDP_LOGGING_ADDR1, configUDP_LOGGING_ADDR2, configUDP_LOGGING_ADDR3 );
+    vLoggingInit( xLogToStdout, xLogToFile, xLogToUDP, ulLoggingIPAddress, configPRINT_PORT );
+
+    /*
+     * Seed random number generator.
+     *
+     * !!!NOTE!!!
+     * This is not a secure method of generating a random number.  Production
+     * devices should use a True Random Number Generator (TRNG).
+     */
+    time( &xTimeNow );
+    LogDebug( ( "Seed for randomizer: %lu\n", xTimeNow ) );
+    prvSRand( ( uint32_t ) xTimeNow );
+    LogDebug( ( "Random numbers: %08X %08X %08X %08X\n", ipconfigRAND32(), ipconfigRAND32(), ipconfigRAND32(), ipconfigRAND32() ) );
+}
+/*-----------------------------------------------------------*/
+
+#if ( ipconfigUSE_LLMNR != 0 ) || ( ipconfigUSE_NBNS != 0 ) || ( ipconfigDHCP_REGISTER_HOSTNAME == 1 )
+
+    const char * pcApplicationHostnameHook( void )
+    {
+        /* Assign the name "FreeRTOS" to this network node.  This function will
+         * be called during the DHCP: the machine will be registered with an IP
+         * address plus this name. */
+        return mainHOST_NAME;
+    }
+
+#endif
+/*-----------------------------------------------------------*/
+
+#if ( ipconfigUSE_LLMNR != 0 ) || ( ipconfigUSE_NBNS != 0 )
+
+    BaseType_t xApplicationDNSQueryHook( const char * pcName )
+    {
+        BaseType_t xReturn;
+
+        /* Determine if a name lookup is for this node.  Two names are given
+         * to this node: that returned by pcApplicationHostnameHook() and that set
+         * by mainDEVICE_NICK_NAME. */
+        if( _stricmp( pcName, pcApplicationHostnameHook() ) == 0 )
+        {
+            xReturn = pdPASS;
+        }
+        else if( _stricmp( pcName, mainDEVICE_NICK_NAME ) == 0 )
+        {
+            xReturn = pdPASS;
+        }
+        else
+        {
+            xReturn = pdFAIL;
+        }
+
+        return xReturn;
+    }
+
+#endif /* if ( ipconfigUSE_LLMNR != 0 ) || ( ipconfigUSE_NBNS != 0 ) */
+/*-----------------------------------------------------------*/
+
+/*
+ * Callback that provides the inputs necessary to generate a randomized TCP
+ * Initial Sequence Number per RFC 6528.  THIS IS ONLY A DUMMY IMPLEMENTATION
+ * THAT RETURNS A PSEUDO RANDOM NUMBER SO IS NOT INTENDED FOR USE IN PRODUCTION
+ * SYSTEMS.
+ */
+extern uint32_t ulApplicationGetNextSequenceNumber( uint32_t ulSourceAddress,
+                                                    uint16_t usSourcePort,
+                                                    uint32_t ulDestinationAddress,
+                                                    uint16_t usDestinationPort )
+{
+    ( void ) ulSourceAddress;
+    ( void ) usSourcePort;
+    ( void ) ulDestinationAddress;
+    ( void ) usDestinationPort;
+
+    return uxRand();
+}
+/*-----------------------------------------------------------*/
+
+/*
+ * Set *pulNumber to a random number, and return pdTRUE. When the random number
+ * generator is broken, it shall return pdFALSE.
+ * The macros ipconfigRAND32() and configRAND32() are not in use
+ * anymore in FreeRTOS+TCP.
+ *
+ * THIS IS ONLY A DUMMY IMPLEMENTATION THAT RETURNS A PSEUDO RANDOM NUMBER SO IS
+ * NOT INTENDED FOR USE IN PRODUCTION SYSTEMS.
+ */
+BaseType_t xApplicationGetRandomNumber( uint32_t * pulNumber )
+{
+    *pulNumber = uxRand();
+    return pdTRUE;
+}
+/*-----------------------------------------------------------*/
+
+/* configUSE_STATIC_ALLOCATION is set to 1, so the application must provide an
+ * implementation of vApplicationGetIdleTaskMemory() to provide the memory that is
+ * used by the Idle task. */
+void vApplicationGetIdleTaskMemory( StaticTask_t ** ppxIdleTaskTCBBuffer,
+                                    StackType_t ** ppxIdleTaskStackBuffer,
+                                    uint32_t * pulIdleTaskStackSize )
+{
+    /* If the buffers to be provided to the Idle task are declared inside this
+     * function then they must be declared static - otherwise they will be allocated on
+     * the stack and so not exists after this function exits. */
+    static StaticTask_t xIdleTaskTCB;
+    static StackType_t uxIdleTaskStack[ configMINIMAL_STACK_SIZE ];
+
+    /* Pass out a pointer to the StaticTask_t structure in which the Idle task's
+     * state will be stored. */
+    *ppxIdleTaskTCBBuffer = &xIdleTaskTCB;
+
+    /* Pass out the array that will be used as the Idle task's stack. */
+    *ppxIdleTaskStackBuffer = uxIdleTaskStack;
+
+    /* Pass out the size of the array pointed to by *ppxIdleTaskStackBuffer.
+     * Note that, as the array is necessarily of type StackType_t,
+     * configMINIMAL_STACK_SIZE is specified in words, not bytes. */
+    *pulIdleTaskStackSize = configMINIMAL_STACK_SIZE;
+}
+/*-----------------------------------------------------------*/
+
+/* configUSE_STATIC_ALLOCATION and configUSE_TIMERS are both set to 1, so the
+ * application must provide an implementation of vApplicationGetTimerTaskMemory()
+ * to provide the memory that is used by the Timer service task. */
+void vApplicationGetTimerTaskMemory( StaticTask_t ** ppxTimerTaskTCBBuffer,
+                                     StackType_t ** ppxTimerTaskStackBuffer,
+                                     uint32_t * pulTimerTaskStackSize )
+{
+    /* If the buffers to be provided to the Timer task are declared inside this
+     * function then they must be declared static - otherwise they will be allocated on
+     * the stack and so not exists after this function exits. */
+    static StaticTask_t xTimerTaskTCB;
+    static StackType_t uxTimerTaskStack[ configTIMER_TASK_STACK_DEPTH ];
+
+    /* Pass out a pointer to the StaticTask_t structure in which the Timer
+     * task's state will be stored. */
+    *ppxTimerTaskTCBBuffer = &xTimerTaskTCB;
+
+    /* Pass out the array that will be used as the Timer task's stack. */
+    *ppxTimerTaskStackBuffer = uxTimerTaskStack;
+
+    /* Pass out the size of the array pointed to by *ppxTimerTaskStackBuffer.
+     * Note that, as the array is necessarily of type StackType_t,
+     * configMINIMAL_STACK_SIZE is specified in words, not bytes. */
+    *pulTimerTaskStackSize = configTIMER_TASK_STACK_DEPTH;
+}
+/*-----------------------------------------------------------*/
diff --git a/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/readme.url b/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/readme.url
new file mode 100644
index 000000000..44ba47713
--- /dev/null
+++ b/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator/readme.url
@@ -0,0 +1,5 @@
+[{000214A0-0000-0000-C000-000000000046}]
+Prop3=19,11
+[InternetShortcut]
+IDList=
+URL=https://www.freertos.org/sntp/sntp-demo.html
diff --git a/FreeRTOS-Plus/Source/Application-Protocols/coreSNTP b/FreeRTOS-Plus/Source/Application-Protocols/coreSNTP
new file mode 160000
+Subproject cbf2696387a91267427c30554140fd5cead2f3d
diff --git a/lexicon.txt b/lexicon.txt
index 3e3a63f62..cb69f36f5 100644
--- a/lexicon.txt
+++ b/lexicon.txt
@@ -71,6 +71,7 @@ backoffalgorithm
 balternatesetting
 baltimore
 barry
+basetime
 basetype
 bauddiv
 baudrate
@@ -158,6 +159,10 @@ burtcmodeem
 busfault
 buttonisr
 bvic
+bytesreceived
+bytesreceived 
+bytessent
+bytessent 
 bytestorecv
 bytestosend
 bytestring
@@ -365,6 +370,7 @@ copybrief
 corehttp
 coremqtt
 corepkcs
+coresntp
 coretasks
 corextend
 correctl
@@ -677,6 +683,7 @@ fcs
 fd
 fde
 fe
+february
 fec
 ferr
 ff
@@ -807,6 +814,7 @@ hetreg
 hfclk
 hfrco
 hfxo
+hh
 hidef
 hifive
 hkdf
@@ -955,6 +963,7 @@ iproduct
 iram
 irda
 iret
+ireturned
 irom
 irq
 irqchannelpreemptionpriority
@@ -980,6 +989,8 @@ itm
 itteratio
 itu
 ivr
+jan
+january
 javascript
 jefferson
 jitp
@@ -1005,6 +1016,7 @@ kickstart
 knowns
 kx
 lapic
+lastsynctickcount
 latestversion
 lathclr
 lathinv
@@ -1308,6 +1320,7 @@ nullptr
 num
 numaker
 numberofitems
+numofservers
 nvic
 nvs
 ocd
@@ -1385,6 +1398,7 @@ pasv
 pathlen
 payloadlength
 pb
+pbasetime
 pbclk
 pbuf
 pbuffer
@@ -1439,6 +1453,7 @@ pcnewdir
 pcommandtorelease
 pcommandtosend
 pcontext
+pcontextbuffer
 pcoverflowedtask
 pcpath
 pcpayload
@@ -1465,6 +1480,7 @@ pctransmittedstring
 pctxbuffer
 pcurl
 pcurldata
+pcurrenttime
 pcwritebuffer
 pd
 pdata
@@ -1759,6 +1775,7 @@ prvsimplezerocopyudpclienttask
 prvsingletasktests
 prvskipnamefield
 prvstartsimplemqttdemo
+prvstartsimplesntpdemo
 prvstartstoptracecommand
 prvstatcommand
 prvstatfscommand
@@ -1810,6 +1827,9 @@ ptal
 ptcpsocket
 pth
 pthingname
+ptime
+ptimeserver
+ptimeservers
 ptm
 ptopicfilter
 ptp
@@ -1843,6 +1863,7 @@ pucstreambufferstoragearea
 pucstring
 puctxbuffer
 pucudppayloadbuffer
+pudpcontext
 pul
 pulcount
 puldigestlen
@@ -2050,6 +2071,7 @@ rng
 rnto
 ro
 robotronics
+rollover
 rom
 rootca
 rootcasize
@@ -2097,6 +2119,8 @@ safertos
 sam
 sama
 samd
+sampleapp
+sampleapptask
 santity
 sarecomtesttasksstillrunning
 saveall
@@ -2141,7 +2165,9 @@ serinterrupt
 serput
 sersource
 sertx
+serveraddr
 serverhost
+serverport
 setbaudratevalue
 setfaketaskpriority
 setimagestate
@@ -2177,6 +2203,7 @@ simultaniously
 singletasks
 sizeof
 sk
+slewrate
 slibxr
 smc
 smclk
@@ -2185,6 +2212,9 @@ smt
 snextcheckvariable
 sni
 snprintf
+sntp
+sntpclienttask
+sntptask
 soc
 sockaddr
 socketauto
@@ -2201,6 +2231,7 @@ sr
 sram
 src
 sren
+ss
 sscanf
 ssi
 ssitask
@@ -2268,6 +2299,7 @@ sysclk
 sysinit
 syst
 systemcoreclock
+systemgetwallclocktime
 systeminit
 systeminithook
 systemirqhandler
@@ -2625,6 +2657,7 @@ usthingnamelength
 ustopicfilterlength
 ustotallength
 utalised
+utc
 utest
 util
 utilise
@@ -3316,7 +3349,8 @@ xyieldpending
 xyieldrequired
 yrdkrl
 yrpbrl
+yyyy
 yyyymmddhhmmss
 zc
 zer
-zynq
+zynq
\ No newline at end of file
diff --git a/manifest.yml b/manifest.yml
index 5a7429a5f..c12563cbc 100644
--- a/manifest.yml
+++ b/manifest.yml
@@ -101,4 +101,11 @@ dependencies:
       url: "https://github.com/aws/ota-for-aws-iot-embedded-sdk"
       path: "FreeRTOS-Plus/Source/AWS/ota"
 
+  - name: "coreSNTP"
+    version: "v1.0.0"
+    repository:
+      type: "git"
+      url: "https://github.com/FreeRTOS/coreSNTP"
+      path: "FreeRTOS-Plus/Source/Application-Protocols/coreSNTP"
+
 license: "MIT"