major revamp:

* oneliner API moved to pysnmp.hlapi.asyncore location
* all hlapi components now pulled from inner modules to into
  pysnmp.hlapi.asyncore.
* LCD configuration moved from SNMP apps classes to be stand-alone
* var-binds MIB<->protocol representation code moved from SNMP apps
  classes to be stand-alone

17 files changed, 2582 insertions, 15 deletions

diff --git a/pysnmp/hlapi/asyncore/__init__.py b/pysnmp/hlapi/asyncore/__init__.py
new file mode 100644
index 0000000..2f815b6
--- /dev/null
+++ b/pysnmp/hlapi/asyncore/__init__.py
@@ -0,0 +1,16 @@
+# This file is necessary to make this directory a package.
+from pysnmp.proto.rfc1902 import *
+from pysnmp.smi.rfc1902 import *
+from pysnmp.hlapi.auth import *
+from pysnmp.hlapi.context import *
+from pysnmp.hlapi.asyncore.transport import *
+from pysnmp.hlapi.asyncore.cmdgen import *
+from pysnmp.hlapi.asyncore.ntforg import *
+from pysnmp.entity.engine import SnmpEngine
+
+try:
+    from pysnmp.hlapi.asyncore._sync.cmdgen import *
+    from pysnmp.hlapi.asyncore._sync.ntforg import *
+except SyntaxError:
+    from pysnmp.hlapi.asyncore._sync.compat.cmdgen import *
+    from pysnmp.hlapi.asyncore._sync.compat.ntforg import *
diff --git a/pysnmp/hlapi/asyncore/_sync/cmdgen.py b/pysnmp/hlapi/asyncore/_sync/cmdgen.py
new file mode 100644
index 0000000..357cc52
--- /dev/null
+++ b/pysnmp/hlapi/asyncore/_sync/cmdgen.py
@@ -0,0 +1,613 @@
+from pysnmp.hlapi.asyncore.cmdgen import *
+from pysnmp.hlapi.varbinds import *
+from pysnmp.proto.rfc1905 import endOfMibView
+from pysnmp.proto.errind import *
+from pyasn1.type.univ import Null
+
+__all__ = ['getCmd', 'nextCmd', 'setCmd', 'bulkCmd']
+
+def getCmd(snmpEngine, authData, transportTarget, contextData, 
+           *varBinds, **options):
+    """Creates a generator to perform one or more SNMP GET queries.
+
+    On each iteration, new SNMP GET request is send (:RFC:`1905#section-4.2.1`).
+    The iterator blocks waiting for response to arrive or error to occur.
+
+    Parameters
+    ----------
+    snmpEngine : :py:class:`~pysnmp.entity.engine.SnmpEngine`
+        Class instance representing SNMP engine.
+
+    authData : :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.CommunityData` or :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.UsmUserData`
+        Class instance representing SNMP credentials.
+
+    transportTarget : :py:class:`~pysnmp.entity.rfc3413.oneliner.target.UdpTransportTarget` or :py:class:`~pysnmp.entity.rfc3413.oneliner.target.Udp6TransportTarget`
+        Class instance representing transport type along with SNMP peer address.
+
+    contextData : :py:class:`~pysnmp.entity.rfc3413.oneliner.ctx.ContextData`
+        Class instance representing SNMP ContextEngineId and ContextName values.
+
+    \*varBinds : :py:class:`~pysnmp.smi.rfc1902.ObjectType`
+        One or more class instances representing MIB variables to place
+        into SNMP request.
+    
+    Other Parameters
+    ----------------
+    \*\*options :
+        Request options:
+
+            * `lookupMib` - load MIB and resolve response MIB variables at
+              the cost of slightly reduced performance. Default is `True`.
+
+    Yields
+    ------
+    errorIndication : str
+        True value indicates SNMP engine error.
+    errorStatus : str
+        True value indicates SNMP PDU error.
+    errorIndex : int
+        Non-zero value refers to `varBinds[errorIndex-1]`
+    varBinds : tuple
+        A sequence of :py:class:`~pysnmp.smi.rfc1902.ObjectType` class
+        instances representing MIB variables returned in SNMP response.
+
+    Raises
+    ------
+    PySnmpError
+        Or its derivative indicating that an error occurred while
+        performing SNMP operation.
+
+    Notes
+    -----
+    The `getCmd` generator will be exhausted immidiately unless
+    a new sequence of `varBinds` are send back into running generator
+    (supported since Python 2.6).
+
+    Examples
+    --------
+    >>> from pysnmp.entity.rfc3413.oneliner.cmdgen import *
+    >>> g = getCmd(SnmpEngine(),
+    ...            CommunityData('public'),
+    ...            UdpTransportTarget(('demo.snmplabs.com', 161)),
+    ...            ContextData(),
+    ...            ObjectType(ObjectIdentity('SNMPv2-MIB', 'sysDescr', 0)))
+    >>> next(g)
+    (None, 0, 0, [ObjectType(ObjectIdentity(ObjectName('1.3.6.1.2.1.1.1.0')), DisplayString('SunOS zeus.snmplabs.com 4.1.3_U1 1 sun4m'))])
+    >>> 
+
+    """
+    def cbFun(snmpEngine, sendRequestHandle,
+              errorIndication, errorStatus, errorIndex,
+              varBinds, cbCtx):
+        cbCtx['errorIndication'] = errorIndication
+        cbCtx['errorStatus'] = errorStatus
+        cbCtx['errorIndex'] = errorIndex
+        cbCtx['varBinds'] = varBinds
+
+    cbCtx = {}
+
+    cmdGen = AsyncCommandGenerator()
+   
+    while True: 
+        if varBinds:
+            cmdGen.getCmd(
+                snmpEngine,
+                authData,
+                transportTarget,
+                contextData,
+                varBinds,
+                (cbFun, cbCtx),
+                options.get('lookupMib', True)
+            )
+
+            snmpEngine.transportDispatcher.runDispatcher()
+
+            errorIndication = cbCtx['errorIndication']
+            errorStatus = cbCtx['errorStatus']
+            errorIndex = cbCtx['errorIndex']
+            varBinds = cbCtx['varBinds']
+        else:
+            errorIndication = errorStatus = errorIndex = None
+            varBinds = []
+
+        varBinds = ( yield errorIndication, errorStatus, errorIndex, varBinds )
+
+        if not varBinds:
+            break
+
+def setCmd(snmpEngine, authData, transportTarget, contextData, 
+           *varBinds, **options):
+    """Creates a generator to perform one or more SNMP SET queries.
+
+    On each iteration, new SNMP SET request is send (:RFC:`1905#section-4.2.5`).
+    The iterator blocks waiting for response to arrive or error to occur.
+
+    Parameters
+    ----------
+    snmpEngine : :py:class:`~pysnmp.entity.engine.SnmpEngine`
+        Class instance representing SNMP engine.
+
+    authData : :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.CommunityData` or :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.UsmUserData`
+        Class instance representing SNMP credentials.
+
+    transportTarget : :py:class:`~pysnmp.entity.rfc3413.oneliner.target.UdpTransportTarget` or :py:class:`~pysnmp.entity.rfc3413.oneliner.target.Udp6TransportTarget`
+        Class instance representing transport type along with SNMP peer address.
+
+    contextData : :py:class:`~pysnmp.entity.rfc3413.oneliner.ctx.ContextData`
+        Class instance representing SNMP ContextEngineId and ContextName values.
+
+    \*varBinds : :py:class:`~pysnmp.smi.rfc1902.ObjectType`
+        One or more class instances representing MIB variables to place
+        into SNMP request.
+    
+    Other Parameters
+    ----------------
+    \*\*options :
+        Request options:
+
+            * `lookupMib` - load MIB and resolve response MIB variables at
+              the cost of slightly reduced performance. Default is `True`.
+              Default is `True`.
+
+    Yields
+    ------
+    errorIndication : str
+        True value indicates SNMP engine error.
+    errorStatus : str
+        True value indicates SNMP PDU error.
+    errorIndex : int
+        Non-zero value refers to `varBinds[errorIndex-1]`
+    varBinds : tuple
+        A sequence of :py:class:`~pysnmp.smi.rfc1902.ObjectType` class
+        instances representing MIB variables returned in SNMP response.
+
+    Raises
+    ------
+    PySnmpError
+        Or its derivative indicating that an error occurred while
+        performing SNMP operation.
+
+    Notes
+    -----
+    The `setCmd` generator will be exhausted immidiately unless
+    a new sequence of `varBinds` are send back into running generator
+    (supported since Python 2.6).
+
+    Examples
+    --------
+    >>> from pysnmp.entity.rfc3413.oneliner.cmdgen import *
+    >>> g = setCmd(SnmpEngine(),
+    ...            CommunityData('public'),
+    ...            UdpTransportTarget(('demo.snmplabs.com', 161)),
+    ...            ContextData(),
+    ...            ObjectType(ObjectIdentity('SNMPv2-MIB', 'sysDescr', 0), 'Linux i386'))
+    >>> next(g)
+    (None, 0, 0, [ObjectType(ObjectIdentity(ObjectName('1.3.6.1.2.1.1.1.0')), DisplayString('Linux i386'))])
+    >>> 
+
+    """
+    def cbFun(snmpEngine, sendRequestHandle,
+              errorIndication, errorStatus, errorIndex,
+              varBinds, cbCtx):
+        cbCtx['errorIndication'] = errorIndication
+        cbCtx['errorStatus'] = errorStatus
+        cbCtx['errorIndex'] = errorIndex
+        cbCtx['varBinds'] = varBinds
+
+    cbCtx = {}
+
+    cmdGen = AsyncCommandGenerator()
+   
+    while True: 
+        if varBinds:
+            cmdGen.setCmd(
+                snmpEngine,
+                authData,
+                transportTarget,
+                contextData,
+                varBinds,
+                (cbFun, cbCtx),
+                options.get('lookupMib', True)
+            )
+
+            snmpEngine.transportDispatcher.runDispatcher()
+
+            errorIndication = cbCtx['errorIndication']
+            errorStatus = cbCtx['errorStatus']
+            errorIndex = cbCtx['errorIndex']
+            varBinds = cbCtx['varBinds']
+        else:
+            errorIndication = errorStatus = errorIndex = None
+            varBinds = []
+
+        varBinds = ( yield errorIndication, errorStatus, errorIndex, varBinds )
+
+        if not varBinds:
+            break
+
+def nextCmd(snmpEngine, authData, transportTarget, contextData, 
+            *varBinds, **options):
+    """Creates a generator to perform one or more SNMP GETNEXT queries.
+
+    On each iteration, new SNMP GETNEXT request is send
+    (:RFC:`1905#section-4.2.2`). The iterator blocks waiting for response
+    to arrive or error to occur.
+
+    Parameters
+    ----------
+    snmpEngine : :py:class:`~pysnmp.entity.engine.SnmpEngine`
+        Class instance representing SNMP engine.
+
+    authData : :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.CommunityData` or :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.UsmUserData`
+        Class instance representing SNMP credentials.
+
+    transportTarget : :py:class:`~pysnmp.entity.rfc3413.oneliner.target.UdpTransportTarget` or :py:class:`~pysnmp.entity.rfc3413.oneliner.target.Udp6TransportTarget`
+        Class instance representing transport type along with SNMP peer address.
+
+    contextData : :py:class:`~pysnmp.entity.rfc3413.oneliner.ctx.ContextData`
+        Class instance representing SNMP ContextEngineId and ContextName values.
+
+    \*varBinds : :py:class:`~pysnmp.smi.rfc1902.ObjectType`
+        One or more class instances representing MIB variables to place
+        into SNMP request.
+    
+    Other Parameters
+    ----------------
+    \*\*options :
+        Request options:
+
+            * `lookupMib` - load MIB and resolve response MIB variables at
+              the cost of slightly reduced performance. Default is `True`.
+              Default is `True`.
+            * `lexicographicMode` - stop iteration when all response MIB
+              variables leave the scope of initial MIB variables in
+              `varBinds`. Default is `True`.
+            * `ignoreNonIncreasingOid` - continue iteration even if response
+              MIB variables (OIDs) are not greater then request MIB variables.
+              Default is `False`.
+            * `maxRows` - stop iteration once this generator instance processed
+              `maxRows` of SNMP conceptual table. Default is `0` (no limit).
+            * `maxCalls` - stop iteration once this generator instance processed
+              `maxCalls` responses. Default is 0 (no limit).
+
+    Yields
+    ------
+    errorIndication : str
+        True value indicates SNMP engine error.
+    errorStatus : str
+        True value indicates SNMP PDU error.
+    errorIndex : int
+        Non-zero value refers to `varBinds[errorIndex-1]`
+    varBinds : tuple
+        A sequence of :py:class:`~pysnmp.smi.rfc1902.ObjectType` class
+        instances representing MIB variables returned in SNMP response.
+
+    Raises
+    ------
+    PySnmpError
+        Or its derivative indicating that an error occurred while
+        performing SNMP operation.
+
+    Notes
+    -----
+    The `nextCmd` generator will be exhausted on any of the following
+    conditions:
+
+    * SNMP engine error occurs thus `errorIndication` is `True`
+    * SNMP PDU `errorStatus` is reported as `True`
+    * SNMP :py:class:`~pysnmp.proto.rfc1905.EndOfMibView` values
+      (also known as *SNMP exception values*) are reported for all
+      MIB variables in `varBinds`
+    * *lexicographicMode* option is set to `False` and all
+      response MIB variables leave the scope of `varBinds`
+
+    At any moment a new sequence of `varBinds` could be send back into
+    running generator (supported since Python 2.6).
+
+    Examples
+    --------
+    >>> from pysnmp.entity.rfc3413.oneliner.cmdgen import *
+    >>> g = nextCmd(SnmpEngine(),
+    ...             CommunityData('public'),
+    ...             UdpTransportTarget(('demo.snmplabs.com', 161)),
+    ...             ContextData(),
+    ...             ObjectType(ObjectIdentity('SNMPv2-MIB', 'sysDescr')))
+    >>> next(g)
+    (None, 0, 0, [ObjectType(ObjectIdentity(ObjectName('1.3.6.1.2.1.1.1.0')), DisplayString('SunOS zeus.snmplabs.com 4.1.3_U1 1 sun4m'))])
+    >>> g.send( [ ObjectType(ObjectIdentity('IF-MIB', 'ifInOctets')) ] )
+    (None, 0, 0, [(ObjectName('1.3.6.1.2.1.2.2.1.10.1'), Counter32(284817787))])
+    """
+    def cbFun(snmpEngine, sendRequestHandle,
+              errorIndication, errorStatus, errorIndex,
+              varBindTable, cbCtx):
+        cbCtx['errorIndication'] = errorIndication
+        cbCtx['errorStatus'] = errorStatus
+        cbCtx['errorIndex'] = errorIndex
+        cbCtx['varBindTable'] = varBindTable
+
+    lookupMib = options.get('lookupMib', True)
+    lexicographicMode = options.get('lexicographicMode', True)
+    ignoreNonIncreasingOid = options.get('ignoreNonIncreasingOid', False)
+    maxRows = options.get('maxRows', 0)
+    maxCalls = options.get('maxCalls', 0)
+
+    cbCtx = {}
+
+    vbProcessor = CommandGeneratorVarBinds()
+
+    cmdGen = AsyncCommandGenerator()
+   
+    initialVars = [ x[0] for x in vbProcessor.makeVarBinds(snmpEngine, varBinds) ]
+
+    totalRows = totalCalls = 0
+
+    while True: 
+        if varBinds:
+            cmdGen.nextCmd(snmpEngine,
+                           authData,
+                           transportTarget,
+                           contextData,
+                           [ (x[0], Null()) for x in varBinds ],
+                           (cbFun, cbCtx),
+                           lookupMib)
+
+            snmpEngine.transportDispatcher.runDispatcher()
+
+            errorIndication = cbCtx['errorIndication']
+            errorStatus = cbCtx['errorStatus']
+            errorIndex = cbCtx['errorIndex']
+
+            if ignoreNonIncreasingOid and errorIndication and \
+                   isinstance(errorIndication, errind.OidNotIncreasing):
+                errorIndication = None
+
+            if errorIndication:
+                yield errorIndication, errorStatus, errorIndex, varBinds
+                return
+            elif errorStatus:
+                if errorStatus == 2:
+                    # Hide SNMPv1 noSuchName error which leaks in here
+                    # from SNMPv1 Agent through internal pysnmp proxy.
+                    errorStatus = errorStatus.clone(0)
+                    errorIndex = errorIndex.clone(0)
+                yield errorIndication, errorStatus, errorIndex, varBinds
+                return
+            else:
+                varBinds = cbCtx['varBindTable'] and cbCtx['varBindTable'][0]
+                for idx, varBind in enumerate(varBinds):
+                    name, val = varBind
+                    if not isinstance(val, Null):
+                        if lexicographicMode or initialVars[idx].isPrefixOf(name):
+                            break
+                else:
+                    return
+
+                totalRows += 1
+                totalCalls += 1
+        else:
+            errorIndication = errorStatus = errorIndex = None
+            varBinds = []
+
+        initialVarBinds = ( yield errorIndication, errorStatus,
+                                  errorIndex, varBinds )
+
+        if initialVarBinds:
+            varBinds = initialVarBinds
+            initialVars = [ x[0] for x in vbProcessor.makeVarBinds(snmpEngine,
+                                                                   varBinds) ]
+
+        if maxRows and totalRows >= maxRows or \
+                 maxCalls and totalCalls >= maxCalls:
+            return
+
+def bulkCmd(snmpEngine, authData, transportTarget, contextData, 
+            nonRepeaters, maxRepetitions, *varBinds, **options):
+    """Creates a generator to perform one or more SNMP GETBULK queries.
+
+    On each iteration, new SNMP GETBULK request is send
+    (:RFC:`1905#section-4.2.3`). The iterator blocks waiting for response
+    to arrive or error to occur.
+
+    Parameters
+    ----------
+    snmpEngine : :py:class:`~pysnmp.entity.engine.SnmpEngine`
+        Class instance representing SNMP engine.
+
+    authData : :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.CommunityData` or :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.UsmUserData`
+        Class instance representing SNMP credentials.
+
+    transportTarget : :py:class:`~pysnmp.entity.rfc3413.oneliner.target.UdpTransportTarget` or :py:class:`~pysnmp.entity.rfc3413.oneliner.target.Udp6TransportTarget`
+        Class instance representing transport type along with SNMP peer address.
+
+    contextData : :py:class:`~pysnmp.entity.rfc3413.oneliner.ctx.ContextData`
+        Class instance representing SNMP ContextEngineId and ContextName values.
+
+    nonRepeaters : int
+        One MIB variable is requested in response for the first 
+        `nonRepeaters` MIB variables in request.
+
+    maxRepetitions : int
+        `maxRepetitions` MIB variables are requested in response for each
+         of the remaining MIB variables in the request (e.g. excluding
+         `nonRepeaters`). Remote SNMP engine may choose lesser value than
+         requested.
+
+    \*varBinds : :py:class:`~pysnmp.smi.rfc1902.ObjectType`
+        One or more class instances representing MIB variables to place
+        into SNMP request.
+    
+    Other Parameters
+    ----------------
+    \*\*options :
+        Request options:
+
+            * `lookupMib` - load MIB and resolve response MIB variables at
+              the cost of slightly reduced performance. Default is `True`.
+              Default is `True`.
+            * `lexicographicMode` - stop iteration when all response MIB
+              variables leave the scope of initial MIB variables in
+              `varBinds`. Default is `True`.
+            * `ignoreNonIncreasingOid` - continue iteration even if response
+              MIB variables (OIDs) are not greater then request MIB variables.
+              Default is `False`.
+            * `maxRows` - stop iteration once this generator instance processed
+              `maxRows` of SNMP conceptual table. Default is `0` (no limit).
+            * `maxCalls` - stop iteration once this generator instance processed
+              `maxCalls` responses. Default is 0 (no limit).
+
+    Yields
+    ------
+    errorIndication : str
+        True value indicates SNMP engine error.
+    errorStatus : str
+        True value indicates SNMP PDU error.
+    errorIndex : int
+        Non-zero value refers to *varBinds[errorIndex-1]
+    varBinds : tuple
+        A sequence of :py:class:`~pysnmp.smi.rfc1902.ObjectType` class
+        instances representing MIB variables returned in SNMP response.
+
+    Raises
+    ------
+    PySnmpError
+        Or its derivative indicating that an error occurred while
+        performing SNMP operation.
+
+    Notes
+    -----
+    The `bulkCmd` generator will be exhausted on any of the following
+    conditions:
+
+    * SNMP engine error occurs thus `errorIndication` is `True`
+    * SNMP PDU `errorStatus` is reported as `True`
+    * SNMP :py:class:`~pysnmp.proto.rfc1905.EndOfMibView` values
+      (also known as *SNMP exception values*) are reported for all
+      MIB variables in `varBinds`
+    * *lexicographicMode* option is set to `False` and all
+      response MIB variables leave the scope of `varBinds`
+
+    At any moment a new sequence of `varBinds` could be send back into
+    running generator (supported since Python 2.6).
+
+    Setting `maxRepetitions` value to 15..50 might significantly improve
+    system performance, as many MIB variables get packed into a single
+    response message at once.
+
+    Examples
+    --------
+    >>> from pysnmp.entity.rfc3413.oneliner.cmdgen import *
+    >>> g = bulkCmd(SnmpEngine(),
+    ...             CommunityData('public'),
+    ...             UdpTransportTarget(('demo.snmplabs.com', 161)),
+    ...             ContextData(),
+    ...             0, 25,
+    ...             ObjectType(ObjectIdentity('SNMPv2-MIB', 'sysDescr')))
+    >>> next(g)
+    (None, 0, 0, [ObjectType(ObjectIdentity(ObjectName('1.3.6.1.2.1.1.1.0')), DisplayString('SunOS zeus.snmplabs.com 4.1.3_U1 1 sun4m'))])
+    >>> g.send( [ ObjectType(ObjectIdentity('IF-MIB', 'ifInOctets')) ] )
+    (None, 0, 0, [(ObjectName('1.3.6.1.2.1.2.2.1.10.1'), Counter32(284817787))])
+    """
+    def cbFun(snmpEngine, sendRequestHandle,
+              errorIndication, errorStatus, errorIndex,
+              varBindTable, cbCtx):
+        cbCtx['errorIndication'] = errorIndication
+        cbCtx['errorStatus'] = errorStatus
+        cbCtx['errorIndex'] = errorIndex
+        cbCtx['varBindTable'] = varBindTable
+
+    lookupMib = options.get('lookupMib', True)
+    lexicographicMode = options.get('lexicographicMode', True)
+    ignoreNonIncreasingOid = options.get('ignoreNonIncreasingOid', False)
+    maxRows = options.get('maxRows', 0)
+    maxCalls = options.get('maxCalls', 0)
+
+    cbCtx = {}
+
+    vbProcessor = CommandGeneratorVarBinds()
+
+    cmdGen = AsyncCommandGenerator()
+   
+    initialVars = [ x[0] for x in vbProcessor.makeVarBinds(snmpEngine, varBinds) ]
+    nullVarBinds = [ False ] * len(initialVars)
+
+    totalRows = totalCalls = 0
+    stopFlag = False
+
+    while not stopFlag: 
+        if maxRows and totalRows < maxRows:
+            maxRepetitions = min(maxRepetitions, maxRows-totalRows)
+
+        cmdGen.bulkCmd(snmpEngine,
+                       authData,
+                       transportTarget,
+                       contextData,
+                       nonRepeaters, maxRepetitions,
+                       [ (x[0], Null()) for x in varBinds ],
+                       (cbFun, cbCtx),
+                       lookupMib)
+
+        snmpEngine.transportDispatcher.runDispatcher()
+
+        errorIndication = cbCtx['errorIndication']
+        errorStatus = cbCtx['errorStatus']
+        errorIndex = cbCtx['errorIndex']
+        varBindTable = cbCtx['varBindTable']
+
+        if ignoreNonIncreasingOid and errorIndication and \
+                isinstance(errorIndication, errind.OidNotIncreasing):
+            errorIndication = None
+
+        if errorIndication:
+            yield errorIndication, errorStatus, errorIndex, \
+                    varBindTable and varBindTable[0] or []
+            if errorIndication != errind.requestTimedOut:
+                return
+        elif errorStatus:
+            if errorStatus == 2:
+                # Hide SNMPv1 noSuchName error which leaks in here
+                # from SNMPv1 Agent through internal pysnmp proxy.
+                errorStatus = errorStatus.clone(0)
+                errorIndex = errorIndex.clone(0)
+            yield errorIndication, errorStatus, errorIndex, \
+                    varBindTable and varBindTable[0] or []
+            return
+        else:
+            for i in range(len(varBindTable)):
+                stopFlag = True
+                if len(varBindTable[i]) != len(initialVars):
+                    varBindTable = i and varBindTable[:i-1] or []
+                    break
+                for j in range(len(varBindTable[i])):
+                    name, val = varBindTable[i][j]
+                    if nullVarBinds[j]:
+                        varBindTable[i][j] = name, endOfMibView
+                        continue
+                    stopFlag = False
+                    if isinstance(val, Null):
+                        nullVarBinds[j] = True
+                    elif not lexicographicMode and \
+                                not initialVars[j].isPrefixOf(name):
+                        varBindTable[i][j] = name, endOfMibView
+                        nullVarBinds[j] = True
+                if stopFlag:
+                    varBindTable = i and varBindTable[:i-1] or []
+                    break
+
+            totalRows += len(varBindTable)
+            totalCalls += 1
+
+            if maxRows and totalRows >= maxRows:
+                if totalRows > maxRows:
+                    varBindTable = varBindTable[:-(totalRows-maxRows)]
+                stopFlag = True
+
+            if maxCalls and totalCalls >= maxCalls:
+                stopFlag = True
+
+            for varBinds in varBindTable:
+                initialVarBinds = ( yield errorIndication, errorStatus,
+                                          errorIndex, varBinds )
+
+                if initialVarBinds:
+                    varBinds = initialVarBinds
+                    initialVars = [ x[0] for x in vbProcessor.makeVarBinds(snmpEngine, varBinds) ]
diff --git a/pysnmp/hlapi/asyncore/_sync/compat/cmdgen.py b/pysnmp/hlapi/asyncore/_sync/compat/cmdgen.py
new file mode 100644
index 0000000..530c376
--- /dev/null
+++ b/pysnmp/hlapi/asyncore/_sync/compat/cmdgen.py
@@ -0,0 +1,266 @@
+#
+# This is a Python 2.6- version of the same file at level up
+#
+from pysnmp.hlapi.asyncore.cmdgen import *
+from pysnmp.hlapi.varbinds import *
+from pysnmp.proto.rfc1905 import endOfMibView
+from pysnmp.proto.errind import *
+from pyasn1.type.univ import Null
+
+__all__ = ['getCmd', 'nextCmd', 'setCmd', 'bulkCmd', 'next']
+
+def next(iter):
+    return iter.next()
+
+def getCmd(snmpEngine, authData, transportTarget, contextData, 
+           *varBinds, **options):
+
+    def cbFun(snmpEngine, sendRequestHandle,
+              errorIndication, errorStatus, errorIndex,
+              varBinds, cbCtx):
+        cbCtx['errorIndication'] = errorIndication
+        cbCtx['errorStatus'] = errorStatus
+        cbCtx['errorIndex'] = errorIndex
+        cbCtx['varBinds'] = varBinds
+
+    cbCtx = {}
+
+    cmdGen = AsyncCommandGenerator()
+   
+    if varBinds:
+        cmdGen.getCmd(
+            snmpEngine,
+            authData,
+            transportTarget,
+            contextData,
+            varBinds,
+            (cbFun, cbCtx),
+            options.get('lookupMib', True)
+        )
+
+        snmpEngine.transportDispatcher.runDispatcher()
+
+        errorIndication = cbCtx['errorIndication']
+        errorStatus = cbCtx['errorStatus']
+        errorIndex = cbCtx['errorIndex']
+        varBinds = cbCtx['varBinds']
+    else:
+        errorIndication = errorStatus = errorIndex = None
+        varBinds = []
+
+    yield errorIndication, errorStatus, errorIndex, varBinds
+
+def setCmd(snmpEngine, authData, transportTarget, contextData, 
+           *varBinds, **options):
+
+    def cbFun(snmpEngine, sendRequestHandle,
+              errorIndication, errorStatus, errorIndex,
+              varBinds, cbCtx):
+        cbCtx['errorIndication'] = errorIndication
+        cbCtx['errorStatus'] = errorStatus
+        cbCtx['errorIndex'] = errorIndex
+        cbCtx['varBinds'] = varBinds
+
+    cbCtx = {}
+
+    cmdGen = AsyncCommandGenerator()
+   
+    while True: 
+        cmdGen.setCmd(
+            snmpEngine,
+            authData,
+            transportTarget,
+            contextData,
+            varBinds,
+            (cbFun, cbCtx),
+            options.get('lookupMib', True)
+        )
+
+        snmpEngine.transportDispatcher.runDispatcher()
+
+        yield cbCtx['errorIndication'],  \
+              cbCtx['errorStatus'], cbCtx['errorIndex'], \
+              cbCtx['varBinds']
+
+        if cbCtx['errorIndication'] != errind.requestTimedOut:
+            break
+
+def nextCmd(snmpEngine, authData, transportTarget, contextData, 
+            *varBinds, **options):
+
+    def cbFun(snmpEngine, sendRequestHandle,
+              errorIndication, errorStatus, errorIndex,
+              varBindTable, cbCtx):
+        cbCtx['errorIndication'] = errorIndication
+        cbCtx['errorStatus'] = errorStatus
+        cbCtx['errorIndex'] = errorIndex
+        cbCtx['varBindTable'] = varBindTable
+
+    lookupMib = options.get('lookupMib', True)
+    lexicographicMode = options.get('lexicographicMode', True)
+    ignoreNonIncreasingOid = options.get('ignoreNonIncreasingOid', False)
+    maxRows = options.get('maxRows', 0)
+    maxCalls = options.get('maxCalls', 0)
+
+    cbCtx = {}
+
+    vbProcessor = CommandGeneratorVarBinds()
+
+    cmdGen = AsyncCommandGenerator()
+   
+    initialVars = [ x[0] for x in vbProcessor.makeVarBinds(snmpEngine, varBinds) ]
+
+    totalRows = totalCalls = 0
+
+    while True: 
+        cmdGen.nextCmd(snmpEngine,
+                       authData,
+                       transportTarget,
+                       contextData,
+                       [ (x[0], Null()) for x in varBinds ],
+                       (cbFun, cbCtx),
+                       lookupMib)
+
+        snmpEngine.transportDispatcher.runDispatcher()
+
+        errorIndication = cbCtx['errorIndication']
+        errorStatus = cbCtx['errorStatus']
+        errorIndex = cbCtx['errorIndex']
+
+        if ignoreNonIncreasingOid and errorIndication and \
+               isinstance(errorIndication, errind.OidNotIncreasing):
+            errorIndication = None
+
+        if errorIndication:
+            yield errorIndication, errorStatus, errorIndex, varBinds
+            if errorIndication != errind.requestTimedOut:
+                return
+        elif errorStatus:
+            if errorStatus == 2:
+                # Hide SNMPv1 noSuchName error which leaks in here
+                # from SNMPv1 Agent through internal pysnmp proxy.
+                errorStatus = errorStatus.clone(0)
+                errorIndex = errorIndex.clone(0)
+            yield errorIndication, errorStatus, errorIndex, varBinds
+            return
+        else:
+            varBinds = cbCtx['varBindTable'] and cbCtx['varBindTable'][0]
+            for idx, varBind in enumerate(varBinds):
+                name, val = varBind
+                if not isinstance(val, Null):
+                    if lexicographicMode or initialVars[idx].isPrefixOf(name):
+                        break
+            else:
+                return
+
+            totalRows += 1
+            totalCalls += 1
+
+            yield errorIndication, errorStatus, errorIndex, varBinds
+
+            if maxRows and totalRows >= maxRows or \
+                     maxCalls and totalCalls >= maxCalls:
+                return
+
+def bulkCmd(snmpEngine, authData, transportTarget, contextData, 
+            nonRepeaters, maxRepetitions, *varBinds, **options):
+
+    def cbFun(snmpEngine, sendRequestHandle,
+              errorIndication, errorStatus, errorIndex,
+              varBindTable, cbCtx):
+        cbCtx['errorIndication'] = errorIndication
+        cbCtx['errorStatus'] = errorStatus
+        cbCtx['errorIndex'] = errorIndex
+        cbCtx['varBindTable'] = varBindTable
+
+    lookupMib = options.get('lookupMib', True)        
+    lexicographicMode = options.get('lexicographicMode', True)
+    ignoreNonIncreasingOid = options.get('ignoreNonIncreasingOid', False)
+    maxRows = options.get('maxRows', 0)
+    maxCalls = options.get('maxCalls', 0)
+
+    cbCtx = {}
+
+    vbProcessor = CommandGeneratorVarBinds()
+
+    cmdGen = AsyncCommandGenerator()
+   
+    initialVars = [ x[0] for x in vbProcessor.makeVarBinds(snmpEngine, varBinds) ]
+    nullVarBinds = [ False ] * len(initialVars)
+
+    totalRows = totalCalls = 0
+    stopFlag = False
+
+    while not stopFlag: 
+        if maxRows and totalRows < maxRows:
+            maxRepetitions = min(maxRepetitions, maxRows-totalRows)
+
+        cmdGen.bulkCmd(snmpEngine,
+                       authData,
+                       transportTarget,
+                       contextData,
+                       nonRepeaters, maxRepetitions,
+                       [ (x[0], Null()) for x in varBinds ],
+                       (cbFun, cbCtx),
+                       lookupMib)
+
+        snmpEngine.transportDispatcher.runDispatcher()
+
+        errorIndication = cbCtx['errorIndication']
+        errorStatus = cbCtx['errorStatus']
+        errorIndex = cbCtx['errorIndex']
+        varBindTable = cbCtx['varBindTable']
+
+        if ignoreNonIncreasingOid and errorIndication and \
+                isinstance(errorIndication, errind.OidNotIncreasing):
+            errorIndication = None
+
+        if errorIndication:
+            yield errorIndication, errorStatus, errorIndex, \
+                    varBindTable and varBindTable[0] or []
+            if errorIndication != errind.requestTimedOut:
+                return
+        elif errorStatus:
+            if errorStatus == 2:
+                # Hide SNMPv1 noSuchName error which leaks in here
+                # from SNMPv1 Agent through internal pysnmp proxy.
+                errorStatus = errorStatus.clone(0)
+                errorIndex = errorIndex.clone(0)
+            yield errorIndication, errorStatus, errorIndex, \
+                    varBindTable and varBindTable[0] or []
+            return
+        else:
+            for i in range(len(varBindTable)):
+                stopFlag = True
+                if len(varBindTable[i]) != len(initialVars):
+                    varBindTable = i and varBindTable[:i-1] or []
+                    break
+                for j in range(len(varBindTable[i])):
+                    name, val = varBindTable[i][j]
+                    if nullVarBinds[j]:
+                        varBindTable[i][j] = name, endOfMibView
+                        continue
+                    stopFlag = False
+                    if isinstance(val, Null):
+                        nullVarBinds[j] = True
+                    elif not lexicographicMode and \
+                                not initialVars[j].isPrefixOf(name):
+                        varBindTable[i][j] = name, endOfMibView
+                        nullVarBinds[j] = True
+                if stopFlag:
+                    varBindTable = i and varBindTable[:i-1] or []
+                    break
+
+            totalRows += len(varBindTable)
+            totalCalls += 1
+
+            if maxRows and totalRows >= maxRows:
+                if totalRows > maxRows:
+                    varBindTable = varBindTable[:-(totalRows-maxRows)]
+                stopFlag = True
+
+            if maxCalls and totalCalls >= maxCalls:
+                stopFlag = True
+
+            for varBinds in varBindTable:
+                yield errorIndication, errorStatus, errorIndex, varBinds
diff --git a/pysnmp/hlapi/asyncore/_sync/compat/ntforg.py b/pysnmp/hlapi/asyncore/_sync/compat/ntforg.py
new file mode 100644
index 0000000..420b3b6
--- /dev/null
+++ b/pysnmp/hlapi/asyncore/_sync/compat/ntforg.py
@@ -0,0 +1,52 @@
+#
+# This is a Python 2.6- version of the same file at level up
+#
+from pysnmp.hlapi.asyncore.ntforg import *
+
+__all__ = ['sendNotification', 'next']
+
+def next(iter):
+    return iter.next()
+
+#
+# Synchronous one-liner SNMP Notification Originator application
+#
+
+def sendNotification(snmpEngine, authData, transportTarget, contextData,
+                     notifyType, varBinds, **options):
+
+    def cbFun(snmpEngine, sendRequestHandle,
+              errorIndication, errorStatus, errorIndex,
+              varBinds, cbCtx):
+        cbCtx['errorIndication'] = errorIndication
+        cbCtx['errorStatus'] = errorStatus
+        cbCtx['errorIndex'] = errorIndex
+        cbCtx['varBinds'] = varBinds
+
+    cbCtx = {}
+
+    ntfOrg = AsyncNotificationOriginator()
+
+    if varBinds:
+        ntfOrg.sendNotification(
+            snmpEngine,
+            authData,
+            transportTarget,
+            contextData,
+            notifyType,
+            varBinds,
+            (cbFun, cbCtx),
+            options.get('lookupMib', True)
+        )
+
+        snmpEngine.transportDispatcher.runDispatcher()
+
+        errorIndication = cbCtx.get('errorIndication')
+        errorStatus = cbCtx.get('errorStatus')
+        errorIndex = cbCtx.get('errorIndex')
+        varBinds = cbCtx.get('varBinds', [])
+    else:
+        errorIndication = errorStatus = errorIndex = None
+        varBinds = []
+
+    yield errorIndication, errorStatus, errorIndex, varBinds
diff --git a/pysnmp/hlapi/asyncore/_sync/ntforg.py b/pysnmp/hlapi/asyncore/_sync/ntforg.py
new file mode 100644
index 0000000..bec88cf
--- /dev/null
+++ b/pysnmp/hlapi/asyncore/_sync/ntforg.py
@@ -0,0 +1,124 @@
+from pysnmp.hlapi.asyncore.ntforg import *
+
+__all__ = ['sendNotification']
+
+def sendNotification(snmpEngine, authData, transportTarget, contextData,
+                     notifyType, varBinds, **options):
+    """Creates a generator to send one or more SNMP notifications.
+
+    On each iteration, new SNMP TRAP or INFORM notification is send
+    (:RFC:`1905#section-4,2,6`). The iterator blocks waiting for 
+    INFORM acknowlegement to arrive or error to occur.
+
+    Parameters
+    ----------
+    snmpEngine : :py:class:`~pysnmp.entity.engine.SnmpEngine`
+        Class instance representing SNMP engine.
+
+    authData : :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.CommunityData` or :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.UsmUserData`
+        Class instance representing SNMP credentials.
+
+    transportTarget : :py:class:`~pysnmp.entity.rfc3413.oneliner.target.UdpTransportTarget` or :py:class:`~pysnmp.entity.rfc3413.oneliner.target.Udp6TransportTarget`
+        Class instance representing transport type along with SNMP peer address.
+
+    contextData : :py:class:`~pysnmp.entity.rfc3413.oneliner.ctx.ContextData`
+        Class instance representing SNMP ContextEngineId and ContextName values.
+
+    notifyType : str
+        Indicates type of notification to be sent. Recognized literal
+        values are *trap* or *inform*.
+
+    varBinds: tuple
+        Single :py:class:`~pysnmp.smi.rfc1902.NotificationType` class instance
+        representing a minimum sequence of MIB variables required for
+        particular notification type.
+        Alternatively, a sequence of :py:class:`~pysnmp.smi.rfc1902.ObjectType`
+        objects could be passed instead. In the latter case it is up to
+        the user to ensure proper Notification PDU contents.
+    
+    Other Parameters
+    ----------------
+    \*\*options :
+        Request options:
+
+            * `lookupMib` - load MIB and resolve response MIB variables at
+              the cost of slightly reduced performance. Default is `True`.
+
+    Yields
+    ------
+    errorIndication : str
+        True value indicates SNMP engine error.
+    errorStatus : str
+        True value indicates SNMP PDU error.
+    errorIndex : int
+        Non-zero value refers to `varBinds[errorIndex-1]`
+    varBinds : tuple
+        A sequence of :py:class:`~pysnmp.smi.rfc1902.ObjectType` class
+        instances representing MIB variables returned in SNMP response.
+
+    Raises
+    ------
+    PySnmpError
+        Or its derivative indicating that an error occurred while
+        performing SNMP operation.
+
+    Notes
+    -----
+    The `sendNotification` generator will be exhausted immidiately unless
+    an instance of :py:class:`~pysnmp.smi.rfc1902.NotificationType` class
+    or a sequence of :py:class:`~pysnmp.smi.rfc1902.ObjectType` `varBinds`
+    are send back into running generator (supported since Python 2.6).
+
+    Examples
+    --------
+    >>> from pysnmp.entity.rfc3413.oneliner.ntforg import *
+    >>> g = sendNotification(SnmpEngine(),
+    ...                      CommunityData('public'),
+    ...                      UdpTransportTarget(('demo.snmplabs.com', 162)),
+    ...                      ContextData(),
+    ...                      'trap',
+    ...                      NotificationType(ObjectIdentity('IF-MIB', 'linkDown')))
+    >>> next(g)
+    (None, 0, 0, [])
+    >>> 
+
+    """
+    def cbFun(snmpEngine, sendRequestHandle,
+              errorIndication, errorStatus, errorIndex,
+              varBinds, cbCtx):
+        cbCtx['errorIndication'] = errorIndication
+        cbCtx['errorStatus'] = errorStatus
+        cbCtx['errorIndex'] = errorIndex
+        cbCtx['varBinds'] = varBinds
+
+    cbCtx = {}
+
+    ntfOrg = AsyncNotificationOriginator()
+
+    while True: 
+        if varBinds:
+            ntfOrg.sendNotification(
+                snmpEngine,
+                authData,
+                transportTarget,
+                contextData,
+                notifyType,
+                varBinds,
+                cbInfo=(cbFun, cbCtx),
+                lookupMib=options.get('lookupMib', True)
+            )
+
+            snmpEngine.transportDispatcher.runDispatcher()
+
+            errorIndication = cbCtx.get('errorIndication')
+            errorStatus = cbCtx.get('errorStatus')
+            errorIndex = cbCtx.get('errorIndex')
+            varBinds = cbCtx.get('varBinds', [])
+        else:
+            errorIndication = errorStatus = errorIndex = None
+            varBinds = []
+
+        varBinds = ( yield errorIndication, errorStatus, errorIndex, varBinds )
+
+        if not varBinds:
+            break
diff --git a/pysnmp/hlapi/asyncore/cmdgen.py b/pysnmp/hlapi/asyncore/cmdgen.py
new file mode 100644
index 0000000..850dade
--- /dev/null
+++ b/pysnmp/hlapi/asyncore/cmdgen.py
@@ -0,0 +1,529 @@
+from sys import version_info
+from pysnmp.entity import config
+from pysnmp.entity.rfc3413 import cmdgen
+from pysnmp.smi.rfc1902 import *
+from pysnmp.hlapi.auth import *
+from pysnmp.hlapi.context import *
+from pysnmp.hlapi.lcd import *
+from pysnmp.hlapi.varbinds import *
+from pysnmp.hlapi.asyncore.transport import *
+from pysnmp.proto import rfc1905, errind
+from pyasn1.type import univ, base
+
+__all__ = ['AsyncCommandGenerator']
+
+class AsyncCommandGenerator:
+    """Creates asyncore-based SNMP Command Generator object.
+
+    This is a high-level wrapper around pure Command Generator
+    impementation that aims at simplyfing 
+    :py:class:`pysnmp.entity.engine.SnmpEngine`'s Local Configuration
+    Datastore (:RFC:`2271#section-3.4.2`) management. Typically,
+    users instantiate `AsyncCommandGenerator` and call its 
+    commmand-specific methods passing them canned Security,
+    Transport and SNMP Context parameters along with
+    :py:class:`~pysnmp.smi.rfc1902.ObjectType` object carrying
+    MIB variables to include with SNMP request. `AsyncCommandGenerator`
+    will manage LCD by applying user-supplied configuratoin parameters
+    and running requested operation.
+
+    See :RFC:`3413#section-3.1` for more information on SNMP
+    Command Generator purpose, design and supported operations.
+
+    """
+    vbProcessor = CommandGeneratorVarBinds()
+    lcd = CommandGeneratorLcdConfigurator()
+
+    def getCmd(self, snmpEngine, authData, transportTarget, contextData, 
+               varBinds, cbInfo, lookupMib=True):
+        """Performs SNMP GET query.
+
+        Based on passed parameters, prepares SNMP GET packet 
+        (:RFC:`1905#section-4.2.1`) and schedules its transmission by
+        I/O framework at a later point of time.
+
+        Parameters
+        ----------
+        snmpEngine : :py:class:`~pysnmp.entity.engine.SnmpEngine`
+            Class instance representing SNMP engine.
+
+        authData : :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.CommunityData` or :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.UsmUserData`
+            Class instance representing SNMP credentials.
+
+        transportTarget : :py:class:`~pysnmp.entity.rfc3413.oneliner.target.UdpTransportTarget` or :py:class:`~pysnmp.entity.rfc3413.oneliner.target.Udp6TransportTarget`
+            Class instance representing transport type along with SNMP peer
+            address.
+
+        contextData : :py:class:`~pysnmp.entity.rfc3413.oneliner.ctx.ContextData`
+            Class instance representing SNMP ContextEngineId and ContextName
+            values.
+
+        varBinds : tuple
+            A sequence of :py:class:`~pysnmp.smi.rfc1902.ObjectType` class
+            instances representing MIB variables to place into SNMP request.
+   
+        cbInfo : tuple
+
+            * `cbFun` - user-supplied callable that is invoked to pass
+              SNMP response data or error to user at a later point of time.
+            * `cbCtx` - user-supplied object passing additional parameters
+              to/from `cbFun`. Default is `None`.
+         
+        Other Parameters
+        ----------------
+        lookupMib : bool
+            `lookupMib` - load MIB and resolve response MIB variables at
+            the cost of slightly reduced performance. Default is `True`.
+
+        Notes
+        -----
+        User-supplied `cbFun` callable must have the following call
+        signature:
+
+        * snmpEngine (:py:class:`~pysnmp.entity.engine.SnmpEngine`): 
+          Class instance representing SNMP engine.
+        * sendRequestHandle (int): Unique request identifier. Can be used 
+          for matching multiple ongoing requests with received responses.
+        * errorIndication (str): True value indicates SNMP engine error.
+        * errorStatus (str): True value indicates SNMP PDU error.
+        * errorIndex (int): Non-zero value refers to `varBinds[errorIndex-1]`
+        * varBinds (tuple): A sequence of 
+          :py:class:`~pysnmp.smi.rfc1902.ObjectType` class instances 
+          representing MIB variables returned in SNMP response in exactly
+          the same order as `varBinds` in request.
+        * `cbCtx` : Original user-supplied object.
+
+        Returns
+        -------
+        sendRequestHandle : int
+            Unique request identifier. Can be used for matching received
+            responses with ongoing requests.
+
+        Raises
+        ------
+        PySnmpError
+            Or its derivative indicating that an error occurred while
+            performing SNMP operation.
+
+        Examples
+        --------
+        >>> from pysnmp.entity.rfc3413.oneliner.cmdgen import *
+        >>> def cbFun(snmpEngine, sendRequestHandle, errorIndication, errorStatus, errorIndex, varBinds, cbCtx):
+        ...     print(errorIndication, errorStatus, errorIndex, varBinds)
+        >>>
+        >>> snmpEngine = SnmpEngine()
+        >>> g = AsyncCommandGenerator()
+        >>> g.getCmd(snmpEngine,
+        ...          CommunityData('public'),
+        ...          UdpTransportTarget(('demo.snmplabs.com', 161)),
+        ...          ContextData(),
+        ...          ObjectType(ObjectIdentity('SNMPv2-MIB', 'sysDescr', 0)),
+        ...          (cbFun, None))
+        >>> snmpEngine.transportDispatcher.runDispatcher()
+        (None, 0, 0, [ObjectType(ObjectIdentity(ObjectName('1.3.6.1.2.1.1.1.0')), DisplayString('SunOS zeus.snmplabs.com 4.1.3_U1 1 sun4m'))])
+        >>>
+
+        """
+        def __cbFun(snmpEngine, sendRequestHandle,
+                    errorIndication, errorStatus, errorIndex,
+                    varBinds, cbCtx):
+            lookupMib, cbFun, cbCtx = cbCtx
+            return cbFun(
+                snmpEngine,
+                sendRequestHandle,
+                errorIndication,
+                errorStatus,
+                errorIndex,
+                self.vbProcessor.unmakeVarBinds(
+                    snmpEngine, varBinds, lookupMib
+                ),
+                cbCtx
+            )
+        
+        (cbFun, cbCtx) = cbInfo
+        addrName, paramsName = self.lcd.configure(
+            snmpEngine, authData, transportTarget
+        )
+
+        return cmdgen.GetCommandGenerator().sendVarBinds(
+            snmpEngine,
+            addrName,
+            contextData.contextEngineId,
+            contextData.contextName,
+            self.vbProcessor.makeVarBinds(snmpEngine, varBinds),
+            __cbFun,
+            (lookupMib, cbFun, cbCtx)
+        )
+    
+    def setCmd(self, snmpEngine, authData, transportTarget, contextData,
+               varBinds, cbInfo, lookupMib=True):
+        """Performs SNMP SET query.
+
+        Based on passed parameters, prepares SNMP SET packet 
+        (:RFC:`1905#section-4.2.5`) and schedules its transmission by
+        I/O framework at a later point of time.
+
+        Parameters
+        ----------
+        snmpEngine : :py:class:`~pysnmp.entity.engine.SnmpEngine`
+            Class instance representing SNMP engine.
+
+        authData : :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.CommunityData` or :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.UsmUserData`
+            Class instance representing SNMP credentials.
+
+        transportTarget : :py:class:`~pysnmp.entity.rfc3413.oneliner.target.UdpTransportTarget` or :py:class:`~pysnmp.entity.rfc3413.oneliner.target.Udp6TransportTarget`
+            Class instance representing transport type along with SNMP peer
+            address.
+
+        contextData : :py:class:`~pysnmp.entity.rfc3413.oneliner.ctx.ContextData`
+            Class instance representing SNMP ContextEngineId and ContextName
+            values.
+
+        varBinds : tuple
+            A sequence of :py:class:`~pysnmp.smi.rfc1902.ObjectType` class
+            instances representing MIB variables to place into SNMP request.
+   
+        cbInfo : tuple
+
+            * `cbFun` - user-supplied callable that is invoked to pass
+              SNMP response data or error to user at a later point of time.
+            * `cbCtx` - user-supplied object passing additional parameters
+              to/from `cbFun`. Default is `None`.
+         
+        Other Parameters
+        ----------------
+        lookupMib : bool
+            `lookupMib` - load MIB and resolve response MIB variables at
+            the cost of slightly reduced performance. Default is `True`.
+
+        Notes
+        -----
+        User-supplied `cbFun` callable must have the following call
+        signature:
+
+        * snmpEngine (:py:class:`~pysnmp.entity.engine.SnmpEngine`): 
+          Class instance representing SNMP engine.
+        * sendRequestHandle (int): Unique request identifier. Can be used 
+          for matching multiple ongoing requests with received responses.
+        * errorIndication (str): True value indicates SNMP engine error.
+        * errorStatus (str): True value indicates SNMP PDU error.
+        * errorIndex (int): Non-zero value refers to `varBinds[errorIndex-1]`
+        * varBinds (tuple): A sequence of 
+          :py:class:`~pysnmp.smi.rfc1902.ObjectType` class instances 
+          representing MIB variables returned in SNMP response in exactly
+          the same order as `varBinds` in request.
+        * `cbCtx` : Original user-supplied object.
+
+        Returns
+        -------
+        sendRequestHandle : int
+            Unique request identifier. Can be used for matching received
+            responses with ongoing requests.
+
+        Raises
+        ------
+        PySnmpError
+            Or its derivative indicating that an error occurred while
+            performing SNMP operation.
+
+        Examples
+        --------
+        >>> from pysnmp.entity.rfc3413.oneliner.cmdgen import *
+        >>> def cbFun(snmpEngine, sendRequestHandle, errorIndication, errorStatus, errorIndex, varBinds, cbCtx):
+        ...     print(errorIndication, errorStatus, errorIndex, varBinds)
+        >>>
+        >>> snmpEngine = SnmpEngine()
+        >>> g = AsyncCommandGenerator()
+        >>> g.setCmd(snmpEngine,
+        ...          CommunityData('public'),
+        ...          UdpTransportTarget(('demo.snmplabs.com', 161)),
+        ...          ContextData(),
+        ...          ObjectType(ObjectIdentity('SNMPv2-MIB', 'sysContact', 0), 'info@snmplabs.com'),
+        ...          (cbFun, None))
+        >>> snmpEngine.transportDispatcher.runDispatcher()
+        (None, 0, 0, [ObjectType(ObjectIdentity(ObjectName('1.3.6.1.2.1.1.4.0')), DisplayString('info@snmplabs.com'))])
+        >>>
+
+        """
+        def __cbFun(snmpEngine, sendRequestHandle,
+                    errorIndication, errorStatus, errorIndex,
+                    varBinds, cbCtx):
+            lookupMib, cbFun, cbCtx = cbCtx
+            return cbFun(
+                snmpEngine,
+                sendRequestHandle,
+                errorIndication,
+                errorStatus,
+                errorIndex,
+                self.vbProcessor.unmakeVarBinds(
+                    snmpEngine, varBinds, lookupMib
+                ),
+                cbCtx
+            )
+
+        (cbFun, cbCtx) = cbInfo
+        addrName, paramsName = self.lcd.configure(
+            snmpEngine, authData, transportTarget
+        )
+
+        return cmdgen.SetCommandGenerator().sendVarBinds(
+            snmpEngine,
+            addrName,
+            contextData.contextEngineId,
+            contextData.contextName,
+            self.vbProcessor.makeVarBinds(snmpEngine, varBinds),
+            __cbFun,
+            (lookupMib, cbFun, cbCtx)
+        )
+    
+    def nextCmd(self, snmpEngine, authData, transportTarget, contextData,
+                varBinds, cbInfo, lookupMib=True):
+        """Performs SNMP GETNEXT query.
+
+        Based on passed parameters, prepares SNMP GETNEXT packet 
+        (:RFC:`1905#section-4.2.2`) and schedules its transmission by
+        I/O framework at a later point of time.
+
+        Parameters
+        ----------
+        snmpEngine : :py:class:`~pysnmp.entity.engine.SnmpEngine`
+            Class instance representing SNMP engine.
+
+        authData : :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.CommunityData` or :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.UsmUserData`
+            Class instance representing SNMP credentials.
+
+        transportTarget : :py:class:`~pysnmp.entity.rfc3413.oneliner.target.UdpTransportTarget` or :py:class:`~pysnmp.entity.rfc3413.oneliner.target.Udp6TransportTarget`
+            Class instance representing transport type along with SNMP peer
+            address.
+
+        contextData : :py:class:`~pysnmp.entity.rfc3413.oneliner.ctx.ContextData`
+            Class instance representing SNMP ContextEngineId and ContextName
+            values.
+
+        varBinds : tuple
+            A sequence of :py:class:`~pysnmp.smi.rfc1902.ObjectType` class
+            instances representing MIB variables to place into SNMP request.
+   
+        cbInfo : tuple
+
+            * `cbFun` - user-supplied callable that is invoked to pass
+              SNMP response data or error to user at a later point of time.
+            * `cbCtx` - user-supplied object passing additional parameters
+              to/from `cbFun`. Default is `None`.
+         
+        Other Parameters
+        ----------------
+        lookupMib : bool
+            `lookupMib` - load MIB and resolve response MIB variables at
+            the cost of slightly reduced performance. Default is `True`.
+
+        Notes
+        -----
+        User-supplied `cbFun` callable must have the following call
+        signature:
+
+        * snmpEngine (:py:class:`~pysnmp.entity.engine.SnmpEngine`): 
+          Class instance representing SNMP engine.
+        * sendRequestHandle (int): Unique request identifier. Can be used 
+          for matching multiple ongoing requests with received responses.
+        * errorIndication (str): True value indicates SNMP engine error.
+        * errorStatus (str): True value indicates SNMP PDU error.
+        * errorIndex (int): Non-zero value refers to `varBinds[errorIndex-1]`
+        * varBinds (tuple): A sequence of sequences (e.g. 2-D array) of
+          :py:class:`~pysnmp.smi.rfc1902.ObjectType` class instances
+          representing a table of MIB variables returned in SNMP response.
+          Inner sequences represent table rows and ordered exactly the same
+          as `varBinds` in request. Response to GETNEXT always contain a
+          single row.
+        * `cbCtx` : Original user-supplied object.
+
+        Returns
+        -------
+        sendRequestHandle : int
+            Unique request identifier. Can be used for matching received
+            responses with ongoing requests.
+
+        Raises
+        ------
+        PySnmpError
+            Or its derivative indicating that an error occurred while
+            performing SNMP operation.
+
+        Examples
+        --------
+        >>> from pysnmp.entity.rfc3413.oneliner.cmdgen import *
+        >>> def cbFun(snmpEngine, sendRequestHandle, errorIndication, errorStatus, errorIndex, varBinds, cbCtx):
+        ...     print(errorIndication, errorStatus, errorIndex, varBinds)
+        >>>
+        >>> snmpEngine = SnmpEngine()
+        >>> g = AsyncCommandGenerator()
+        >>> g.nextCmd(snmpEngine,
+        ...           CommunityData('public'),
+        ...           UdpTransportTarget(('demo.snmplabs.com', 161)),
+        ...           ContextData(),
+        ...           ObjectType(ObjectIdentity('SNMPv2-MIB', 'system')),
+        ...           (cbFun, None))
+        >>> snmpEngine.transportDispatcher.runDispatcher()
+        (None, 0, 0, [ [ObjectType(ObjectIdentity(ObjectName('1.3.6.1.2.1.1.1.0')), DisplayString('SunOS zeus.snmplabs.com 4.1.3_U1 1 sun4m'))] ])
+        >>>
+
+        """
+        def __cbFun(snmpEngine, sendRequestHandle,
+                    errorIndication, errorStatus, errorIndex,
+                    varBindTable, cbCtx):
+            lookupMib, cbFun, cbCtx = cbCtx
+            return cbFun(
+                snmpEngine,
+                sendRequestHandle,
+                errorIndication,
+                errorStatus,
+                errorIndex,
+                [ self.vbProcessor.unmakeVarBinds(snmpEngine, varBindTableRow, lookupMib) for varBindTableRow in varBindTable ],
+                cbCtx
+            )
+
+        (cbFun, cbCtx) = cbInfo
+        addrName, paramsName = self.lcd.configure(
+            snmpEngine, authData, transportTarget
+        )
+        return cmdgen.NextCommandGenerator().sendVarBinds(
+            snmpEngine,
+            addrName,
+            contextData.contextEngineId, contextData.contextName,
+            self.vbProcessor.makeVarBinds(snmpEngine, varBinds),
+            __cbFun,
+            (lookupMib, cbFun, cbCtx)
+        )
+
+    def bulkCmd(self, snmpEngine, authData, transportTarget, contextData,
+                nonRepeaters, maxRepetitions, varBinds, cbInfo,
+                lookupMib=True):
+        """Performs SNMP GETBULK query.
+
+        Based on passed parameters, prepares SNMP GETBULK packet 
+        (:RFC:`1905#section-4.2.3`) and schedules its transmission by
+        I/O framework at a later point of time.
+
+        Parameters
+        ----------
+        snmpEngine : :py:class:`~pysnmp.entity.engine.SnmpEngine`
+            Class instance representing SNMP engine.
+
+        authData : :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.CommunityData` or :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.UsmUserData`
+            Class instance representing SNMP credentials.
+
+        transportTarget : :py:class:`~pysnmp.entity.rfc3413.oneliner.target.UdpTransportTarget` or :py:class:`~pysnmp.entity.rfc3413.oneliner.target.Udp6TransportTarget`
+            Class instance representing transport type along with SNMP peer
+            address.
+
+        contextData : :py:class:`~pysnmp.entity.rfc3413.oneliner.ctx.ContextData`
+            Class instance representing SNMP ContextEngineId and ContextName
+            values.
+
+        nonRepeaters : int
+            One MIB variable is requested in response for the first 
+            `nonRepeaters` MIB variables in request.
+
+        maxRepetitions : int
+            `maxRepetitions` MIB variables are requested in response for each
+            of the remaining MIB variables in the request (e.g. excluding
+            `nonRepeaters`). Remote SNMP engine may choose lesser value than
+            requested.
+
+        varBinds : tuple
+            A sequence of :py:class:`~pysnmp.smi.rfc1902.ObjectType` class
+            instances representing MIB variables to place into SNMP request.
+   
+        cbInfo : tuple
+
+            * `cbFun` - user-supplied callable that is invoked to pass
+              SNMP response data or error to user at a later point of time.
+            * `cbCtx` - user-supplied object passing additional parameters
+              to/from `cbFun`. Default is `None`.
+         
+        Other Parameters
+        ----------------
+        lookupMib : bool
+            `lookupMib` - load MIB and resolve response MIB variables at
+            the cost of slightly reduced performance. Default is `True`.
+
+        Notes
+        -----
+        User-supplied `cbFun` callable must have the following call
+        signature:
+
+        * snmpEngine (:py:class:`~pysnmp.entity.engine.SnmpEngine`): 
+          Class instance representing SNMP engine.
+        * sendRequestHandle (int): Unique request identifier. Can be used 
+          for matching multiple ongoing requests with received responses.
+        * errorIndication (str): True value indicates SNMP engine error.
+        * errorStatus (str): True value indicates SNMP PDU error.
+        * errorIndex (int): Non-zero value refers to `varBinds[errorIndex-1]`
+        * varBinds (tuple): A sequence of sequences (e.g. 2-D array) of
+          :py:class:`~pysnmp.smi.rfc1902.ObjectType` class instances
+          representing a table of MIB variables returned in SNMP response.
+          Inner sequences represent table rows and ordered exactly the same
+          as `varBinds` in request. Number of rows might be less or equal
+          to `maxRepetitions` value in request.
+        * `cbCtx` : Original user-supplied object.
+
+        Returns
+        -------
+        sendRequestHandle : int
+            Unique request identifier. Can be used for matching received
+            responses with ongoing requests.
+
+        Raises
+        ------
+        PySnmpError
+            Or its derivative indicating that an error occurred while
+            performing SNMP operation.
+
+        Examples
+        --------
+        >>> from pysnmp.entity.rfc3413.oneliner.cmdgen import *
+        >>> def cbFun(snmpEngine, sendRequestHandle, errorIndication, errorStatus, errorIndex, varBinds, cbCtx):
+        ...     print(errorIndication, errorStatus, errorIndex, varBinds)
+        >>>
+        >>> snmpEngine = SnmpEngine()
+        >>> g = AsyncCommandGenerator()
+        >>> g.bulkCmd(snmpEngine,
+        ...           CommunityData('public'),
+        ...           UdpTransportTarget(('demo.snmplabs.com', 161)),
+        ...           ContextData(),
+        ...           0, 2,
+        ...           ObjectType(ObjectIdentity('SNMPv2-MIB', 'system')),
+        ...           (cbFun, None))
+        >>> snmpEngine.transportDispatcher.runDispatcher()
+        (None, 0, 0, [ [ObjectType(ObjectIdentity(ObjectName('1.3.6.1.2.1.1.1.0')), DisplayString('SunOS zeus.snmplabs.com 4.1.3_U1 1 sun4m')), ObjectType(ObjectIdentity(ObjectName('1.3.6.1.2.1.1.2.0')), ObjectIdentifier('1.3.6.1.4.1.424242.1.1')] ])
+        >>>
+
+        """
+        def __cbFun(snmpEngine, sendRequestHandle,
+                    errorIndication, errorStatus, errorIndex,
+                    varBindTable, cbCtx):
+            lookupMib, cbFun, cbCtx = cbCtx
+            return cbFun(
+                snmpEngine,
+                sendRequestHandle,
+                errorIndication,
+                errorStatus,
+                errorIndex,
+                [ self.vbProcessor.unmakeVarBinds(snmpEngine, varBindTableRow, lookupMib) for varBindTableRow in varBindTable ],
+                cbCtx
+            )
+
+        (cbFun, cbCtx) = cbInfo
+        addrName, paramsName = self.lcd.configure(
+            snmpEngine, authData, transportTarget
+        )
+        return cmdgen.BulkCommandGenerator().sendVarBinds(
+            snmpEngine,
+            addrName,
+            contextData.contextEngineId,
+            contextData.contextName,
+            nonRepeaters, maxRepetitions,
+            self.vbProcessor.makeVarBinds(snmpEngine, varBinds),
+            __cbFun,
+            (lookupMib, cbFun, cbCtx)
+        )
diff --git a/pysnmp/hlapi/asyncore/ntforg.py b/pysnmp/hlapi/asyncore/ntforg.py
new file mode 100644
index 0000000..6536b9c
--- /dev/null
+++ b/pysnmp/hlapi/asyncore/ntforg.py
@@ -0,0 +1,169 @@
+from pysnmp.entity import engine, config
+from pysnmp.smi.rfc1902 import *
+from pysnmp.entity.rfc3413 import ntforg, context
+from pysnmp.hlapi.auth import *
+from pysnmp.hlapi.context import *
+from pysnmp.hlapi.lcd import *
+from pysnmp.hlapi.varbinds import *
+from pysnmp.hlapi.asyncore.transport import *
+from pysnmp.hlapi.asyncore import cmdgen
+from pysnmp import error
+
+__all__ = ['AsyncNotificationOriginator']
+
+class AsyncNotificationOriginator:
+    """Creates asyncore-based SNMP Notification Originator object.
+
+    This is a high-level wrapper around pure Notification Originator
+    impementation that aims at simplyfing 
+    :py:class:`pysnmp.entity.engine.SnmpEngine`'s Local Configuration
+    Datastore (:RFC:`2271#section-3.4.2`) management. Typically,
+    users instantiate `AsyncNotificationOriginator` and call its 
+    commmand-specific methods passing them canned Security,
+    Transport and SNMP Context parameters along with
+    :py:class:`~pysnmp.smi.rfc1902.NotificationType` object carrying
+    MIB variables to include with Notification. `AsyncNotificationOriginator`
+    will manage LCD by applying user-supplied configuratoin parameters
+    and running requested operation.
+
+    See :RFC:`3413#section-3.2` for more information on SNMP
+    Notification Originator purpose, design and supported operations.
+
+    """
+    vbProcessor = NotificationOriginatorVarBinds()
+    lcd = NotificationOriginatorLcdConfigurator()
+
+    def sendNotification(self, snmpEngine,
+                         authData, transportTarget, contextData,
+                         notifyType,
+                         varBinds,
+                         cbInfo=(None, None), 
+                         lookupMib=False):
+        """Send SNMP notification.
+
+        Based on passed parameters, prepares SNMP TRAP or INFORM
+        notification (:RFC:`1905#section-4.2.6`) and schedules its
+        transmission by I/O framework at a later point of time.
+
+        Parameters
+        ----------
+        snmpEngine : :py:class:`~pysnmp.entity.engine.SnmpEngine`
+            Class instance representing SNMP engine.
+
+        authData : :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.CommunityData` or :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.UsmUserData`
+            Class instance representing SNMP credentials.
+
+        transportTarget : :py:class:`~pysnmp.entity.rfc3413.oneliner.target.UdpTransportTarget` or :py:class:`~pysnmp.entity.rfc3413.oneliner.target.Udp6TransportTarget`
+            Class instance representing transport type along with SNMP peer
+            address.
+
+        contextData : :py:class:`~pysnmp.entity.rfc3413.oneliner.ctx.ContextData`
+            Class instance representing SNMP ContextEngineId and ContextName
+            values.
+
+        notifyType : str
+            Indicates type of notification to be sent. Recognized literal
+            values are *trap* or *inform*.
+
+        varBinds: tuple
+            Single :py:class:`~pysnmp.smi.rfc1902.NotificationType` class
+            instance representing a minimum sequence of MIB variables
+            required for particular notification type. Alternatively,
+            a sequence of :py:class:`~pysnmp.smi.rfc1902.ObjectType`
+            objects could be passed instead. In the latter case it is up to
+            the user to ensure proper Notification PDU contents.
+    
+        cbInfo : tuple
+
+            * `cbFun` - user-supplied callable that is invoked to pass
+              SNMP response to *INFORM* notification or error to user at
+              a later point of time. The `cbFun` callable is never invoked
+              for *TRAP* notifications.
+            * `cbCtx` - user-supplied object passing additional parameters
+              to/from `cbFun`. Default is `None`.
+         
+        Other Parameters
+        ----------------
+        lookupMib : bool
+            `lookupMib` - load MIB and resolve response MIB variables at
+            the cost of slightly reduced performance. Default is `True`.
+
+        Notes
+        -----
+        User-supplied `cbFun` callable must have the following call
+        signature:
+
+        * snmpEngine (:py:class:`~pysnmp.entity.engine.SnmpEngine`): 
+          Class instance representing SNMP engine.
+        * sendRequestHandle (int): Unique request identifier. Can be used 
+          for matching multiple ongoing *INFORM* notifications with received
+          responses.
+        * errorIndication (str): True value indicates SNMP engine error.
+        * errorStatus (str): True value indicates SNMP PDU error.
+        * errorIndex (int): Non-zero value refers to `varBinds[errorIndex-1]`
+        * varBinds (tuple): A sequence of 
+          :py:class:`~pysnmp.smi.rfc1902.ObjectType` class instances 
+          representing MIB variables returned in SNMP response in exactly
+          the same order as `varBinds` in request.
+        * `cbCtx` : Original user-supplied object.
+
+        Returns
+        -------
+        sendRequestHandle : int
+            Unique request identifier. Can be used for matching received
+            responses with ongoing *INFORM* requests. Returns `None` for
+            *TRAP* notifications.
+
+        Raises
+        ------
+        PySnmpError
+            Or its derivative indicating that an error occurred while
+            performing SNMP operation.
+
+        Examples
+        --------
+        >>> from pysnmp.entity.rfc3413.oneliner.ntforg import *
+        >>>
+        >>> snmpEngine = SnmpEngine()
+        >>> n = AsyncNotificationOriginator()
+        >>> n.sendNotification(
+        ...     snmpEngine,
+        ...     CommunityData('public'),
+        ...     UdpTransportTarget(('demo.snmplabs.com', 162)),
+        ...     ContextData(),
+        ...     'trap',
+        ...     NotificationType(ObjectIdentity('SNMPv2-MIB', 'coldStart')),
+        ... )
+        >>> snmpEngine.transportDispatcher.runDispatcher()
+        >>>
+
+        """
+        def __cbFun(snmpEngine, sendRequestHandle, errorIndication,
+                    errorStatus, errorIndex, varBinds, cbCtx):
+            lookupMib, cbFun, cbCtx = cbCtx
+            return cbFun and cbFun(
+                snmpEngine,
+                sendRequestHandle,
+                errorIndication,
+                errorStatus, errorIndex,
+                self.vbProcessor.unmakeVarBinds(
+                    snmpEngine, varBinds, lookupMib
+                ),
+                cbCtx
+            )
+
+        cbFun, cbCtx = cbInfo
+
+        # Create matching transport tags if not given by user
+        if not transportTarget.tagList:
+            transportTarget.tagList = str(
+                hash((authData.securityName, transportTarget.transportAddr))
+            )
+        if isinstance(authData, CommunityData) and not authData.tag:
+            authData.tag = transportTarget.tagList.split()[0]
+
+        notifyName = self.lcd.configure(
+            snmpEngine, authData, transportTarget, notifyType
+        )
+
+        return ntforg.NotificationOriginator().sendVarBinds(snmpEngine, notifyName, contextData.contextEngineId, contextData.contextName, self.vbProcessor.makeVarBinds(snmpEngine, varBinds), __cbFun, (lookupMib, cbFun, cbCtx))
diff --git a/pysnmp/hlapi/asyncore/transport.py b/pysnmp/hlapi/asyncore/transport.py
new file mode 100644
index 0000000..f77f575
--- /dev/null
+++ b/pysnmp/hlapi/asyncore/transport.py
@@ -0,0 +1,150 @@
+import socket, sys
+from pysnmp.carrier.asyncore.dgram import udp, udp6, unix
+from pysnmp import error
+from pyasn1.compat.octets import null
+
+__all__ = ['UnixTransportTarget', 'Udp6TransportTarget', 'UdpTransportTarget']
+
+class _AbstractTransportTarget:
+    transportDomain = None
+    protoTransport = NotImplementedError
+    def __init__(self, transportAddr, timeout=1, retries=5, tagList=null):
+        self.transportAddr = self._resolveAddr(transportAddr)
+        self.timeout = timeout
+        self.retries = retries
+        self.tagList = tagList
+        self.iface = None
+
+    def __repr__(self): 
+        return '%s(%r, timeout=%r, retries=%r, tagList=%r)' % (
+            self.__class__.__name__, self.transportAddr,
+            self.timeout, self.retries, self.tagList
+        )
+
+    def getTransportInfo(self):
+        return self.transportDomain, self.transportAddr
+
+    def setLocalAddress(self, iface):
+        self.iface = iface
+        return self
+
+    def openClientMode(self):
+        self.transport = self.protoTransport().openClientMode(self.iface)
+        return self.transport
+
+    def verifyDispatcherCompatibility(self, snmpEngine):
+        if not self.protoTransport.isCompatibleWithDispatcher(snmpEngine.transportDispatcher):
+            raise error.PySnmpError('Transport %r is not compatible with dispatcher %r' % (self.protoTransport, snmpEngine.transportDispatcher))
+
+    def _resolveAddr(self, transportAddr): raise NotImplementedError()
+
+class UdpTransportTarget(_AbstractTransportTarget):
+    """Creates UDP/IPv4 configuration entry and initialize socket API if needed.
+
+    This object can be used by 
+    :py:class:`~pysnmp.entity.rfc3413.oneliner.cmdgen.AsyncCommandGenerator` or
+    :py:class:`~pysnmp.entity.rfc3413.oneliner.ntforg.AsyncNotificationOriginator`
+    and their derevatives for adding new entries to Local Configuration
+    Datastore (LCD) managed by :py:class:`~pysnmp.entity.engine.SnmpEngine`
+    class instance.
+
+    See :RFC:`1906#section-3` for more information on the UDP transport mapping.
+
+    Parameters
+    ----------
+    transportAddr : tuple
+        Indicates remote address in Python :py:mod:`socket` module format
+        which is a tuple of FQDN, port where FQDN is a string representing
+        either hostname or IPv4 address in quad-dotted form, port is an
+        integer.
+    timeout : int
+        Response timeout in seconds.
+    retries : int
+        Maximum number of request retries, 0 retries means just a single
+        request.
+    tagList : str
+        Arbitrary string that contains a list of tag values which are used
+        to select target addresses for a particular operation 
+        (:RFC:`3413#section-4.1.4`).
+
+    Examples
+    --------
+    >>> from pysnmp.entity.rfc3413.oneliner.target import UdpTransportTarget
+    >>> UdpTransportTarget(('demo.snmplabs.com', 161))
+    UdpTransportTarget(('195.218.195.228', 161), timeout=1, retries=5, tagList='')
+    >>> 
+
+    """
+    transportDomain = udp.domainName
+    protoTransport = udp.UdpSocketTransport
+    def _resolveAddr(self, transportAddr):
+        try:
+            return socket.getaddrinfo(transportAddr[0],
+                                      transportAddr[1],
+                                      socket.AF_INET,
+                                      socket.SOCK_DGRAM,
+                                      socket.IPPROTO_UDP)[0][4][:2]
+        except socket.gaierror:
+            raise error.PySnmpError('Bad IPv4/UDP transport address %s: %s' % ('@'.join([ str(x) for x in transportAddr ]), sys.exc_info()[1]))
+
+class Udp6TransportTarget(_AbstractTransportTarget):
+    """Creates UDP/IPv6 configuration entry and initialize socket API if needed.
+
+    This object can be used by 
+    :py:class:`~pysnmp.entity.rfc3413.oneliner.cmdgen.AsyncCommandGenerator` or
+    :py:class:`~pysnmp.entity.rfc3413.oneliner.ntforg.AsyncNotificationOriginator`
+    and their derevatives for adding new entries to Local Configuration
+    Datastore (LCD) managed by :py:class:`~pysnmp.entity.engine.SnmpEngine`
+    class instance.
+
+    See :RFC:`1906#section-3`, :RFC:`2851#section-4` for more information
+    on the UDP and IPv6 transport mapping.
+
+    Parameters
+    ----------
+    transportAddr : tuple
+        Indicates remote address in Python :py:mod:`socket` module format
+        which is a tuple of FQDN, port where FQDN is a string representing
+        either hostname or IPv6 address in one of three conventional forms
+        (:RFC:`1924#section-3`), port is an integer.
+    timeout : int
+        Response timeout in seconds.
+    retries : int
+        Maximum number of request retries, 0 retries means just a single
+        request.
+    tagList : str
+        Arbitrary string that contains a list of tag values which are used
+        to select target addresses for a particular operation
+        (:RFC:`3413#section-4.1.4`).
+
+    Examples
+    --------
+    >>> from pysnmp.entity.rfc3413.oneliner.target import Udp6TransportTarget
+    >>> Udp6TransportTarget(('google.com', 161))
+    Udp6TransportTarget(('2a00:1450:4014:80a::100e', 161), timeout=1, retries=5, tagList='')
+    >>> Udp6TransportTarget(('FEDC:BA98:7654:3210:FEDC:BA98:7654:3210', 161))
+    Udp6TransportTarget(('fedc:ba98:7654:3210:fedc:ba98:7654:3210', 161), timeout=1, retries=5, tagList='')
+    >>> Udp6TransportTarget(('1080:0:0:0:8:800:200C:417A', 161))
+    Udp6TransportTarget(('1080::8:800:200c:417a', 161), timeout=1, retries=5, tagList='')
+    >>> Udp6TransportTarget(('::0', 161))
+    Udp6TransportTarget(('::', 161), timeout=1, retries=5, tagList='')
+    >>> Udp6TransportTarget(('::', 161))
+    Udp6TransportTarget(('::', 161), timeout=1, retries=5, tagList='')
+    >>> 
+
+    """
+    transportDomain = udp6.domainName
+    protoTransport = udp6.Udp6SocketTransport
+    def _resolveAddr(self, transportAddr):
+        try:
+            return socket.getaddrinfo(transportAddr[0],
+                                      transportAddr[1],
+                                      socket.AF_INET6,
+                                      socket.SOCK_DGRAM,
+                                      socket.IPPROTO_UDP)[0][4][:2]
+        except socket.gaierror:
+            raise error.PySnmpError('Bad IPv6/UDP transport address %s: %s' % ('@'.join([ str(x) for x in transportAddr ]), sys.exc_info()[1]))
+
+class UnixTransportTarget(_AbstractTransportTarget):
+    transportDomain = unix.domainName
+    protoTransport = unix.UnixSocketTransport
diff --git a/pysnmp/hlapi/auth.py b/pysnmp/hlapi/auth.py
new file mode 100644
index 0000000..5108a21
--- /dev/null
+++ b/pysnmp/hlapi/auth.py
@@ -0,0 +1,278 @@
+from pysnmp.entity import config
+from pysnmp import error
+from pyasn1.compat.octets import null
+
+__all__ = ['CommunityData', 'UsmUserData',
+           'usm3DESEDEPrivProtocol', 'usmAesCfb128Protocol',
+           'usmAesCfb192Protocol', 'usmAesCfb256Protocol',
+           'usmDESPrivProtocol', 'usmHMACMD5AuthProtocol',
+           'usmHMACSHAAuthProtocol', 'usmNoAuthProtocol',
+           'usmNoPrivProtocol']
+
+class CommunityData:
+    """Creates SNMP v1/v2c configuration entry.
+
+    This object can be used by 
+    :py:class:`~pysnmp.entity.rfc3413.oneliner.cmdgen.AsyncCommandGenerator` or
+    :py:class:`~pysnmp.entity.rfc3413.oneliner.ntforg.AsyncNotificationOriginator`
+    and their derivatives for adding new entries to Local Configuration
+    Datastore (LCD) managed by :py:class:`~pysnmp.entity.engine.SnmpEngine`
+    class instance.
+
+    See :RFC:`2576#section-5.3` for more information on the 
+    *SNMP-COMMUNITY-MIB::snmpCommunityTable*.
+
+    Parameters
+    ----------
+    communityIndex : str
+        Unique index value of a row in snmpCommunityTable. If it is the
+        only positional parameter, it is taken as *communityName*.
+    communityName : str
+        SNMP v1/v2c community string.
+    mpModel : int
+        SNMP version - 0 for SNMPv1 and 1 for SNMPv2c.
+    contextEngineId : str
+        Indicates the location of the context in which management
+        information is accessed when using the community string
+        specified by the above communityName.
+    contextName : str
+        The context in which management information is accessed when
+        using the above communityName.
+    tag : str 
+        Arbitrary string that specifies a set of transport endpoints
+        to which a notification may be sent using communityName above
+        (see also :RFC:`3413#section-4.1.4`).
+
+    Examples
+    --------
+    >>> from pysnmp.entity.rfc3413.oneliner.auth import CommunityData
+    >>> CommunityData('public')
+    CommunityData(communityIndex='s1410706889', communityName=<COMMUNITY>, mpModel=1, contextEngineId=None, contextName='', tag='')
+    >>> CommunityData('public', 'public')
+    CommunityData(communityIndex='public', communityName=<COMMUNITY>, mpModel=1, contextEngineId=None, contextName='', tag='')
+    >>>
+
+    """
+    mpModel = 1 # Default is SMIv2
+    securityModel = mpModel + 1
+    securityLevel = 'noAuthNoPriv'
+    contextName = null
+    tag = null
+    def __init__(self, communityIndex, communityName=None, mpModel=None,
+                 contextEngineId=None, contextName=None, tag=None,
+                 securityName=None):
+        if mpModel is not None:
+            self.mpModel = mpModel
+            self.securityModel = mpModel + 1
+        self.contextEngineId = contextEngineId
+        if contextName is not None:
+            self.contextName = contextName
+        if tag is not None:
+            self.tag = tag
+        # a single arg is considered as a community name
+        if communityName is None:
+            communityName, communityIndex = communityIndex, None
+        self.communityName = communityName
+        # Autogenerate communityIndex if not specified
+        if communityIndex is None:
+            self.communityIndex = self.securityName = 's%s' % hash(
+                ( self.communityName,
+                  self.mpModel,
+                  self.contextEngineId,
+                  self.contextName,
+                  self.tag )
+            )
+        else:
+            self.communityIndex = communityIndex
+            self.securityName = securityName is not None and securityName or communityIndex
+
+    def __hash__(self):
+        raise TypeError('%s is not hashable' % self.__class__.__name__)
+
+    def __repr__(self):
+        return '%s(communityIndex=%r, communityName=<COMMUNITY>, mpModel=%r, contextEngineId=%r, contextName=%r, tag=%r, securityName=%r)' % (
+            self.__class__.__name__,
+            self.communityIndex,
+            self.mpModel,
+            self.contextEngineId,
+            self.contextName,
+            self.tag,
+            self.securityName
+        )
+
+    def clone(self, communityIndex=None, communityName=None,
+              mpModel=None, contextEngineId=None,
+              contextName=None, tag=None, securityName=None):
+        # a single arg is considered as a community name
+        if communityName is None:
+            communityName, communityIndex = communityIndex, None
+        return self.__class__(
+            communityIndex,
+            communityName is None and self.communityName or communityName,
+            mpModel is None and self.mpModel or mpModel,
+            contextEngineId is None and self.contextEngineId or contextEngineId,
+            contextName is None and self.contextName or contextName,
+            tag is None and self.tag or tag,
+            securityName is None and self.securityName or securityName
+        )
+
+#: No Authentication Protocol.
+usmNoAuthProtocol = config.usmNoAuthProtocol
+#: The HMAC-MD5-96 Digest Authentication Protocol (:RFC:`3414#section-6`)
+usmHMACMD5AuthProtocol = config.usmHMACMD5AuthProtocol
+#: The HMAC-SHA-96 Digest Authentication Protocol (:RFC:`3414#section-7`) 
+usmHMACSHAAuthProtocol = config.usmHMACSHAAuthProtocol
+
+#: No Privacy Protocol.
+usmNoPrivProtocol = config.usmNoPrivProtocol
+#: The CBC-DES Symmetric Encryption Protocol (:RFC:`3414#section-8`)
+usmDESPrivProtocol = config.usmDESPrivProtocol
+#: The 3DES-EDE Symmetric Encryption Protocol (`draft-reeder-snmpv3-usm-3desede-00 <https://tools.ietf.org/html/draft-reeder-snmpv3-usm-3desede-00#section-5>`_)
+usm3DESEDEPrivProtocol = config.usm3DESEDEPrivProtocol
+#: The CFB128-AES-128 Symmetric Encryption Protocol (:RFC:`3826#section-3`)
+usmAesCfb128Protocol = config.usmAesCfb128Protocol
+#: The CFB128-AES-192 Symmetric Encryption Protocol (`draft-blumenthal-aes-usm-04 <https://tools.ietf.org/html/draft-blumenthal-aes-usm-04#section-3>`_)
+usmAesCfb192Protocol = config.usmAesCfb192Protocol
+#: The CFB128-AES-256 Symmetric Encryption Protocol (`draft-blumenthal-aes-usm-04 <https://tools.ietf.org/html/draft-blumenthal-aes-usm-04#section-3>`_)
+usmAesCfb256Protocol = config.usmAesCfb256Protocol
+
+class UsmUserData:
+    """Creates SNMP v3 User Security Model (USM) configuration entry.
+
+    This object can be used by 
+    :py:class:`~pysnmp.entity.rfc3413.oneliner.cmdgen.AsyncCommandGenerator` or
+    :py:class:`~pysnmp.entity.rfc3413.oneliner.ntforg.AsyncNotificationOriginator`
+    and their derivatives for adding new entries to Local Configuration
+    Datastore (LCD) managed by :py:class:`~pysnmp.entity.engine.SnmpEngine`
+    class instance.
+
+    See :RFC:`3414#section-5` for more information on the 
+    *SNMP-USER-BASED-SM-MIB::usmUserTable*.
+
+    Parameters
+    ----------
+    userName : str
+        A human readable string representing the name of the SNMP USM user.
+    authKey : str
+        Initial value of the secret authentication key.  If not set,
+        :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.usmNoAuthProtocol`
+        is implied.  If set and no *authProtocol* is specified,
+        :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.usmHMACMD5AuthProtocol`
+        takes effect.
+    privKey : str
+        Initial value of the secret encryption key.  If not set,
+        :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.usmNoPrivProtocol`
+        is implied.  If set and no *privProtocol* is specified,
+        :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.usmDESPrivProtocol`
+        takes effect.
+    authProtocol : tuple
+        An indication of whether messages sent on behalf of this USM user
+        can be authenticated, and if so, the type of authentication protocol
+        which is used.
+
+        Supported authentication protocol identifiers are:
+
+        * :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.usmNoAuthProtocol` (default is *authKey* not given)
+        * :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.usmHMACMD5AuthProtocol` (default if *authKey* is given)
+        * :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.usmHMACSHAAuthProtocol`
+    privProtocol : tuple
+        An indication of whether messages sent on behalf of this USM user 
+        be encrypted, and if so, the type of encryption protocol which is used.
+
+        Supported encryption protocol identifiers are:
+
+        * :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.usmNoPrivProtocol` (default is *authKey* not given)
+        * :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.usmDESPrivProtocol` (default if *authKey* is given)
+        * :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.usm3DESEDEPrivProtocol`
+        * :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.usmAesCfb128Protocol`
+        * :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.usmAesCfb192Protocol`
+        * :py:class:`~pysnmp.entity.rfc3413.oneliner.auth.usmAesCfb256Protocol`
+
+    Examples
+    --------
+    >>> from pysnmp.entity.rfc3413.oneliner.auth import UsmUserData
+    >>> UsmUserData('testuser', authKey='authenticationkey')
+    UsmUserData(userName='testuser', authKey=<AUTHKEY>, privKey=<PRIVKEY>, authProtocol=(1,3,6,1,6,3,10,1,1,2), privProtocol=(1,3,6,1,6,3,10,1,2,1))
+    >>> UsmUserData('testuser', authKey='authenticationkey', privKey='encryptionkey')
+    UsmUserData(userName='testuser', authKey=<AUTHKEY>, privKey=<PRIVKEY>, authProtocol=(1,3,6,1,6,3,10,1,1,2), privProtocol=(1,3,6,1,6,3,10,1,2,2))
+    >>>
+
+    """
+    authKey = privKey = None
+    authProtocol = config.usmNoAuthProtocol
+    privProtocol = config.usmNoPrivProtocol
+    securityLevel = 'noAuthNoPriv'
+    securityModel = 3
+    mpModel = 3
+    contextName = null
+    # the contextEngineId/contextName values stored here should
+    # be used for USM configuration only, not for PDU contents
+    def __init__(self, userName,
+                 authKey=None, privKey=None,
+                 authProtocol=None, privProtocol=None,
+                 securityEngineId=None,
+                 # deprecated parameters begin
+                 contextName=None,
+                 contextEngineId=None,
+                 # deprecated parameters end
+                 securityName=None):
+        self.userName = userName
+        if securityName is None:
+            self.securityName = userName
+        else:
+            self.securityName = securityName
+        
+        if authKey is not None:
+            self.authKey = authKey
+            if authProtocol is None:
+                self.authProtocol = config.usmHMACMD5AuthProtocol
+            else:
+                self.authProtocol = authProtocol
+            if self.securityLevel != 'authPriv':
+                self.securityLevel = 'authNoPriv'
+
+        if privKey is not None:
+            self.privKey = privKey
+            if self.authProtocol == config.usmNoAuthProtocol:
+                raise error.PySnmpError('Privacy implies authenticity')
+            self.securityLevel = 'authPriv'
+            if privProtocol is None:
+                self.privProtocol = config.usmDESPrivProtocol
+            else:
+                self.privProtocol = privProtocol
+
+        # the contextEngineId parameter is actually a securityEngineId
+        if securityEngineId is None:
+            securityEngineId = contextEngineId
+        self.contextEngineId = self.securityEngineId = securityEngineId
+
+        # the contextName parameter should never be used here
+        if contextName is not None:
+            self.contextName = contextName
+        
+    def __hash__(self):
+        raise TypeError('%s is not hashable' % self.__class__.__name__)
+
+    def __repr__(self):
+        return '%s(userName=%r, authKey=<AUTHKEY>, privKey=<PRIVKEY>, authProtocol=%r, privProtocol=%r, securityEngineId=%r, securityName=%r)'%(
+            self.__class__.__name__,
+            self.userName,
+            self.authProtocol,
+            self.privProtocol,
+            self.securityEngineId is None and '<DEFAULT>' or self.securityEngineId,
+            self.securityName
+        )
+
+    def clone(self, userName=None,
+              authKey=None, privKey=None,
+              authProtocol=None, privProtocol=None,
+              securityEngineId=None, securityName=None):
+        return self.__class__(
+            userName is None and self.userName or userName,
+            authKey is None and self.authKey or authKey,
+            privKey is None and self.privKey or privKey,
+            authProtocol is None and self.authProtocol or authProtocol,
+            privProtocol is None and self.privProtocol or privProtocol,
+            securityEngineId is None and self.securityEngineId or securityEngineId,
+            securityName=securityName is None and self.securityName or securityName
+        )
diff --git a/pysnmp/hlapi/context.py b/pysnmp/hlapi/context.py
new file mode 100644
index 0000000..0d86480
--- /dev/null
+++ b/pysnmp/hlapi/context.py
@@ -0,0 +1,48 @@
+from pyasn1.compat.octets import null
+
+__all__ = ['ContextData']
+
+class ContextData:
+    """Creates UDP/IPv6 configuration entry and initialize socket API if needed.
+
+    This object can be used by 
+    :py:class:`~pysnmp.entity.rfc3413.oneliner.cmdgen.AsyncCommandGenerator` or
+    :py:class:`~pysnmp.entity.rfc3413.oneliner.ntforg.AsyncNotificationOriginator`
+    and their derevatives for forming SNMP PDU and also adding new entries to
+    Local Configuration Datastore (LCD) in order to support SNMPv1/v2c with
+    SNMPv3 interoperability.
+
+    See :RFC:`3411#section-4.1` for SNMP Context details.
+
+    Parameters
+    ----------
+    contextEngineId : str
+        Uniquely identifies an SNMP entity that may realize an instance of 
+        a MIB with a particular contextName (:RFC:`3411#section-3.3.2`).
+        More frequently than not, ContextEngineID is the same as 
+        authoritative SnmpEngineID, however if SNMP Engine serves multiple
+        SNMP Entities, their ContextEngineIDs would be distinct.
+        Default is authoritative SNMP Engine ID.
+    contextName : str
+        Used to name an instance of MIB (:RFC:`3411#section-3.3.3`).
+        Default is empty string.
+
+    Examples
+    --------
+    >>> from pysnmp.entity.rfc3413.oneliner.ctx import ContextData
+    >>> ContextData()
+    ContextData(contextEngineId=None, contextName='')
+    >>> ContextData(OctetString(hexValue='01020ABBA0'))
+    ContextData(contextEngineId=OctetString(hexValue='01020abba0'), contextName='')
+    >>> ContextData(contextName='mycontext')
+    ContextData(contextEngineId=None, contextName='mycontext')
+
+    """        
+    def __init__(self, contextEngineId=None, contextName=null):
+        self.contextEngineId = contextEngineId
+        self.contextName = contextName
+
+    def __repr__(self):
+        return '%s(contextEngineId=%r, contextName=%r)' % (
+            self.__class__.__name__, self.contextEngineId, self.contextName
+        )
diff --git a/pysnmp/hlapi/lcd.py b/pysnmp/hlapi/lcd.py
new file mode 100644
index 0000000..e62eaf1
--- /dev/null
+++ b/pysnmp/hlapi/lcd.py
@@ -0,0 +1,259 @@
+from pysnmp.entity import config
+from pysnmp import nextid, error
+from pysnmp.hlapi.auth import *
+
+__all__ = ['CommandGeneratorLcdConfigurator',
+           'NotificationOriginatorLcdConfigurator' ]
+
+class AbstractLcdConfigurator:
+    nextID = nextid.Integer(0xffffffff)
+
+    def _getCache(self, snmpEngine):
+        cache = snmpEngine.getUserContext(self.__class__.__name__)
+        if cache is None:
+            cache = {
+                'auth': {}, 'parm': {}, 'tran': {}, 'addr': {}
+            }
+            snmpEngine.setUserContext(cmdgen_cache=cache)
+        return cache
+
+    def configure(self, snmpEngine, authData, transportTarget): pass
+    def unconfigure(self, snmpEngine, authData=None): pass
+
+class CommandGeneratorLcdConfigurator(AbstractLcdConfigurator):
+    def configure(self, snmpEngine, authData, transportTarget):
+        cache = self._getCache(snmpEngine)
+        if isinstance(authData, CommunityData):
+            if authData.communityIndex not in cache['auth']:
+                config.addV1System(
+                    snmpEngine,
+                    authData.communityIndex,
+                    authData.communityName,
+                    authData.contextEngineId,
+                    authData.contextName,
+                    authData.tag,
+                    authData.securityName
+                )
+                cache['auth'][authData.communityIndex] = authData
+        elif isinstance(authData, UsmUserData):
+            authDataKey = authData.userName, authData.securityEngineId
+            if authDataKey not in cache['auth']:
+                config.addV3User(
+                    snmpEngine,
+                    authData.userName,
+                    authData.authProtocol, authData.authKey,
+                    authData.privProtocol, authData.privKey,
+                    authData.securityEngineId,
+                    securityName=authData.securityName
+                )
+                cache['auth'][authDataKey] = authData
+        else:
+            raise error.PySnmpError('Unsupported authentication object')
+
+        paramsKey = authData.securityName, \
+                    authData.securityLevel, \
+                    authData.mpModel
+        if paramsKey in cache['parm']:
+            paramsName, useCount = cache['parm'][paramsKey]
+            cache['parm'][paramsKey] = paramsName, useCount + 1
+        else:
+            paramsName = 'p%s' % self.nextID()
+            config.addTargetParams(
+                snmpEngine, paramsName,
+                authData.securityName, authData.securityLevel, authData.mpModel
+            )
+            cache['parm'][paramsKey] = paramsName, 1
+
+        if transportTarget.transportDomain in cache['tran']:
+            transport, useCount = cache['tran'][transportTarget.transportDomain]
+            transportTarget.verifyDispatcherCompatibility(snmpEngine)
+            cache['tran'][transportTarget.transportDomain] = transport, useCount + 1
+        elif config.getTransport(snmpEngine, transportTarget.transportDomain):
+            transportTarget.verifyDispatcherCompatibility(snmpEngine)
+        else:
+            transport = transportTarget.openClientMode()
+            config.addTransport(
+                snmpEngine,
+                transportTarget.transportDomain,
+                transport
+            )
+            cache['tran'][transportTarget.transportDomain] = transport, 1
+
+        transportKey = ( paramsName,
+                         transportTarget.transportDomain,
+                         transportTarget.transportAddr,
+                         transportTarget.tagList )
+
+        if transportKey in cache['addr']:
+            addrName, useCount = cache['addr'][transportKey]
+            cache['addr'][transportKey] = addrName, useCount + 1
+        else:
+            addrName = 'a%s' % self.nextID()
+            config.addTargetAddr(
+                snmpEngine, addrName,
+                transportTarget.transportDomain,
+                transportTarget.transportAddr,
+                paramsName,
+                transportTarget.timeout * 100,
+                transportTarget.retries,
+                transportTarget.tagList
+            )
+            cache['addr'][transportKey] = addrName, 1
+
+        return addrName, paramsName
+
+    def unconfigure(self, snmpEngine, authData=None):
+        cache = _getCache(snmpEngine)
+        if authData:
+            if isinstance(authData, CommunityData):
+                authDataKey = authData.communityIndex
+            elif isinstance(authData, UsmUserData):
+                authDataKey = authData.userName, authData.securityEngineId
+            else:
+                raise error.PySnmpError('Unsupported authentication object')
+            if authDataKey in cache['auth']:
+                authDataKeys = ( authDataKey, )
+            else:
+                raise error.PySnmpError('Unknown authData %s' % (authData,))
+        else:
+            authDataKeys = list(cache['auth'].keys())
+
+        addrNames, paramsNames = set(), set()
+
+        for authDataKey in authDataKeys:
+            authDataX = cache['auth'][authDataKey] 
+            del cache['auth'][authDataKey]
+            if isinstance(authDataX, CommunityData):
+                config.delV1System(
+                    snmpEngine,
+                    authDataX.communityIndex
+                )
+            elif isinstance(authDataX, UsmUserData):
+                config.delV3User(
+                    snmpEngine,
+                    authDataX.userName, 
+                    authDataX.securityEngineId
+                )
+            else:
+                raise error.PySnmpError('Unsupported authentication object')
+
+            paramsKey = authDataX.securityName, \
+                        authDataX.securityLevel, \
+                        authDataX.mpModel
+            if paramsKey in cache['parm']:
+                paramsName, useCount = cache['parm'][paramsKey]
+                useCount -= 1
+                if useCount:
+                    cache['parm'][paramsKey] = paramsName, useCount
+                else:
+                    del cache['parm'][paramsKey]
+                    config.delTargetParams(
+                        snmpEngine, paramsName
+                    )
+                    paramsNames.add(paramsName)
+            else:
+                raise error.PySnmpError('Unknown target %s' % (paramsKey,))
+
+            addrKeys = [ x for x in cache['addr'] if x[0] == paramsName ]
+
+            for addrKey in addrKeys:
+                addrName, useCount = cache['addr'][addrKey]
+                useCount -= 1
+                if useCount:
+                    cache['addr'][addrKey] = addrName, useCount
+                else:
+                    config.delTargetAddr(snmpEngine, addrName)
+
+                    addrNames.add(addrKey)
+
+                    if addrKey[1] in cache['tran']:
+                        transport, useCount = cache['tran'][addrKey[1]]
+                        if useCount > 1:
+                            useCount -= 1
+                            cache['tran'][addrKey[1]] = transport, useCount
+                        else:
+                            config.delTransport(snmpEngine, addrKey[1])
+                            transport.closeTransport()
+                            del cache['tran'][addrKey[1]]
+
+        return addrNames, paramsNames
+
+class NotificationOriginatorLcdConfigurator(CommandGeneratorLcdConfigurator):
+    def configure(self, snmpEngine, authData, transportTarget, notifyType):
+        cache = self._getCache(snmpEngine)
+        addrName, paramsName = CommandGeneratorLcdConfigurator.configure(self, snmpEngine, authData, transportTarget)
+        tagList = transportTarget.tagList.split()
+        if not tagList:
+            tagList = ['']
+        for tag in tagList:
+            notifyNameKey = paramsName, tag, notifyType
+            if notifyNameKey in cache['name']:
+                notifyName, paramsName, useCount = cache['name'][notifyNameKey]
+                cache['name'][notifyNameKey] = notifyName, paramsName, useCount + 1
+            else:
+                notifyName = 'n%s' % self.nextID()
+                config.addNotificationTarget(
+                    snmpEngine,
+                    notifyName,
+                    paramsName,
+                    tag,
+                    notifyType
+                )
+                cache['name'][notifyNameKey] = notifyName, paramsName, 1
+        authDataKey = authData.securityName, authData.securityModel
+        if  authDataKey in cache['auth']:
+            authDataX, subTree, useCount = cache['auth'][authDataKey]
+            cache['auth'][authDataKey] = authDataX, subTree, useCount + 1
+        else:
+            subTree = (1,3,6)
+            config.addTrapUser(
+                snmpEngine,
+                authData.securityModel,
+                authData.securityName,
+                authData.securityLevel,
+                subTree
+            )
+            cache['auth'][authDataKey] = authData, subTree, 1
+
+        return notifyName
+
+    def unconfigure(self, snmpEngine, authData=None):
+        cache = _getCache(snmpEngine)
+        if authData:
+            authDataKey = authData.securityName, authData.securityModel
+            if authDataKey in cache['auth']:
+                authDataKeys = ( authDataKey, )
+            else:
+                raise error.PySnmpError('Unknown authData %s' % (authData,))
+        else:
+            authDataKeys = tuple(cache['auth'].keys())
+
+        addrNames, paramsNames = CommandGeneratorLcdConfigurator.unconfigure(self, snmpEngine, authData)
+
+        notifyAndParamsNames = [ (cache['name'][x], x) for x in cache['name'].keys() if x[0] in paramsNames ]
+
+        for (notifyName, paramsName, useCount), notifyNameKey in notifyAndParamsNames:
+            useCount -= 1
+            if useCount:
+                cache['name'][notifyNameKey] = notifyName, paramsName, useCount
+            else:
+                config.delNotificationTarget(
+                    snmpEngine, notifyName, paramsName
+                )
+                del cache['name'][notifyNameKey]
+
+        for authDataKey in authDataKeys:
+            authDataX, subTree, useCount = cache['auth'][authDataKey]
+            useCount -= 1
+            if useCount:
+                cache['auth'][authDataKey] = authDataX, subTree, useCount
+            else:
+                config.delTrapUser(
+                    snmpEngine,
+                    authDataX.securityModel,
+                    authDataX.securityName,
+                    authDataX.securityLevel,
+                    subTree
+                )
+                del cache['auth'][authDataKey]
+
diff --git a/pysnmp/hlapi/varbinds.py b/pysnmp/hlapi/varbinds.py
new file mode 100644
index 0000000..1f32847
--- /dev/null
+++ b/pysnmp/hlapi/varbinds.py
@@ -0,0 +1,62 @@
+from pysnmp.smi import view
+from pysnmp.smi.rfc1902 import *
+
+__all__ = ['CommandGeneratorVarBinds', 'NotificationOriginatorVarBinds']
+
+class AbstractVarBinds:
+    def getMibViewController(self, snmpEngine):
+        mibViewController = snmpEngine.getUserContext('mibViewController')
+        if not mibViewController:
+            mibViewController = view.MibViewController(
+                snmpEngine.getMibBuilder()
+            )
+            snmpEngine.setUserContext(mibViewController=mibViewController)
+        return mibViewController
+    
+class CommandGeneratorVarBinds(AbstractVarBinds):
+    def makeVarBinds(self, snmpEngine, varBinds):
+        mibViewController = self.getMibViewController(snmpEngine)
+        __varBinds = []
+        for varBind in varBinds:
+            if isinstance(varBind, ObjectType):
+                pass
+            elif isinstance(varBind[0], ObjectIdentity):
+                varBind = ObjectType(*varBind)
+            elif isinstance(varBind[0][0], tuple):  # legacy
+                varBind = ObjectType(ObjectIdentity(varBind[0][0][0], varBind[0][0][1], *varBind[0][1:]), varBind[1])
+            else:
+                varBind = ObjectType(ObjectIdentity(varBind[0]), varBind[1])
+
+            __varBinds.append(varBind.resolveWithMib(mibViewController))
+
+        return __varBinds
+
+    def unmakeVarBinds(self, snmpEngine, varBinds, lookupMib=True):
+        if lookupMib:
+            mibViewController = self.getMibViewController(snmpEngine)
+            varBinds = [ ObjectType(ObjectIdentity(x[0]), x[1]).resolveWithMib(mibViewController) for x in varBinds ]
+
+        return varBinds
+
+class NotificationOriginatorVarBinds(AbstractVarBinds):
+    def makeVarBinds(self, snmpEngine, varBinds):
+        mibViewController = self.getMibViewController(snmpEngine)
+        if isinstance(varBinds, NotificationType):
+            varBinds.resolveWithMib(mibViewController)
+        __varBinds = []
+        for varBind in varBinds:
+            if isinstance(varBind, ObjectType):
+                pass
+            elif isinstance(varBind[0], ObjectIdentity):
+                varBind = ObjectType(*varBind)
+            else:
+                varBind = ObjectType(ObjectIdentity(varBind[0]), varBind[1])
+            __varBinds.append(varBind.resolveWithMib(mibViewController))
+        return __varBinds
+
+    def unmakeVarBinds(self, snmpEngine, varBinds, lookupMib=False):
+        if lookupMib:
+            mibViewController = self.getMibViewController(snmpEngine)
+            varBinds = [ ObjectType(ObjectIdentity(x[0]), x[1]).resolveWithMib(mibViewController) for x in varBinds ]
+        return varBinds
+
diff --git a/pysnmp/proto/rfc1155.py b/pysnmp/proto/rfc1155.py
index 6f67f0a..4fb9aec 100644
--- a/pysnmp/proto/rfc1155.py
+++ b/pysnmp/proto/rfc1155.py
@@ -2,6 +2,9 @@ from pyasn1.type import univ, tag, constraint, namedtype
 from pyasn1.error import PyAsn1Error
 from pysnmp.proto import error
 
+__all__ = ['Opaque', 'NetworkAddress', 'ObjectName', 'TimeTicks',
+           'Counter', 'Gauge', 'IpAddress']
+
 class IpAddress(univ.OctetString):
     tagSet = univ.OctetString.tagSet.tagImplicitly(
         tag.Tag(tag.tagClassApplication, tag.tagFormatSimple, 0x00)
diff --git a/pysnmp/proto/rfc1157.py b/pysnmp/proto/rfc1157.py
index 4483cf1..6fd1643 100644
--- a/pysnmp/proto/rfc1157.py
+++ b/pysnmp/proto/rfc1157.py
@@ -1,6 +1,9 @@
 from pyasn1.type import univ, tag, namedtype, namedval
 from pysnmp.proto import rfc1155
 
+__all__ = ['GetNextRequestPDU', 'GetResponsePDU', 'SetRequestPDU',
+           'TrapPDU', 'GetRequestPDU']
+
 class VarBind(univ.Sequence):
     componentType = namedtype.NamedTypes(
         namedtype.NamedType('name', rfc1155.ObjectName()),
diff --git a/pysnmp/proto/rfc1902.py b/pysnmp/proto/rfc1902.py
index b284140..08e64ab 100644
--- a/pysnmp/proto/rfc1902.py
+++ b/pysnmp/proto/rfc1902.py
@@ -1,6 +1,10 @@
 from pyasn1.type import univ, tag, constraint, namedtype, namedval
 from pysnmp.proto import rfc1155, error
 
+__all__ = ['Opaque', 'TimeTicks', 'Bits', 'Integer', 'OctetString',
+           'IpAddress', 'Counter64', 'Unsigned32', 'Gauge32', 'Integer32',
+           'ObjectIdentifier', 'Counter32']
+
 class Integer32(univ.Integer):
     """Creates an instance of SNMP Integer32 class.
 
diff --git a/pysnmp/proto/rfc1905.py b/pysnmp/proto/rfc1905.py
index e77912f..945b32b 100644
--- a/pysnmp/proto/rfc1905.py
+++ b/pysnmp/proto/rfc1905.py
@@ -1,6 +1,12 @@
 from pyasn1.type import univ, tag, constraint, namedtype, namedval
 from pysnmp.proto import rfc1902
 
+__all__ = ['unSpecified', 'EndOfMibView', 'ReportPDU', 'UnSpecified',
+           'BulkPDU', 'SNMPv2TrapPDU', 'GetRequestPDU', 'NoSuchObject',
+           'GetNextRequestPDU', 'GetBulkRequestPDU', 'NoSuchInstance',
+           'ResponsePDU', 'noSuchObject', 'InformRequestPDU', 'endOfMibView',
+           'SetRequestPDU', 'noSuchInstance']
+
 # Value reference -- max bindings in VarBindList
 max_bindings = rfc1902.Integer(2147483647)
 
diff --git a/pysnmp/smi/rfc1902.py b/pysnmp/smi/rfc1902.py
index b61f5a0..2ab5a8c 100644
--- a/pysnmp/smi/rfc1902.py
+++ b/pysnmp/smi/rfc1902.py
@@ -8,21 +8,6 @@ from pyasn1.type.base import AbstractSimpleAsn1Item
 from pyasn1.error import PyAsn1Error
 from pysnmp import debug
 
-# expose SNMP types in this namespace for convenience
-Integer = rfc1902.Integer
-Integer32 = rfc1902.Integer32
-OctetString = rfc1902.OctetString
-ObjectIdentifier = rfc1902.ObjectIdentifier
-IpAddress = rfc1902.IpAddress
-Counter32 = rfc1902.Counter32
-Gauge32 = rfc1902.Gauge32
-Unsigned32 = rfc1902.Unsigned32
-TimeTicks = rfc1902.TimeTicks
-Opaque = rfc1902.Opaque
-Counter64 = rfc1902.Counter64
-Bits = rfc1902.Bits
-ObjectName = rfc1902.ObjectName
-
 class ObjectIdentity:
     """Create an object representing MIB variable ID.