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diff --git a/ACE/examples/QOS/Diffserv/README b/ACE/examples/QOS/Diffserv/README new file mode 100644 index 00000000000..285d514ad12 --- /dev/null +++ b/ACE/examples/QOS/Diffserv/README @@ -0,0 +1,107 @@ +This directory contains an example which +tests the setting of the Diffserv Codepoint (DSCP) +values in the +IP TOS field of a stream of UDP packets. + +Running the example +=================== + +(1) On one host, run: + server [UDP port number] + + If port number is omitted, a default port number of 20002 + is used. + +(2) On a second host, run: + diffserv_test [destination host] [destination port] + + The host and port of where the server is running should + be specified. + + A stream of UDP packets will be sent from to the server, + with various codepoints set. + +(3) Look at the Diffserv Field (formerly known as the TOS field) + of your packets, using a protocol analyzer, such as Ethereal. + + + + +Introduction +============ +In RFC 2474, the Type of Service (TOS) field in +the IP header was renamed the Diffserv (DS) field. +The DS field is one octet (8 bits). + + 0 1 2 3 4 5 6 7 + +---+---+---+---+---+---+---+---+ + | DSCP | ECN | + +---+---+---+---+---+---+---+---+ + +The first 6 bits of the field are +reserved for the Diffserv Codepoint (DSCP). +There are 64 possible values (0-63) for the DSCP. + +Bits 6 and 7 of the DS field are reserved +for Explicit Congestion Notification (ECN). +ECN is defined in RFC 3168. + + +Per-Hop Behaviors (PHB) +======================= + +A Per-Hop Behavior (PHB) is a description of the externally +observable forwarding treatment applied at a differentiated +services compliant node. + +Certain PHB's are defined in RFC's and associated with +different DSCP values. Other values are undefined and left +for experimentation. Please refer to the RFC's for a full +explanation of the attributes of the various PHB's. + + +DSCP value PHB RFC +(binary) +----------------------------------------------------------- +000000 Default (Best Effort) 2474 +001000 Class Selector (CS1) 2474 +010000 Class Selector (CS2) 2474 +011000 Class Selector (CS3) 2474 +100000 Class Selector (CS4) 2474 +101000 Class Selector (CS5) 2474 +110000 Class Selector (CS6) 2474 +111000 Class Selector (CS7) 2474 +001010 Assured Forwarding (AF11) 2597 +001100 Assured Forwarding (AF12) 2597 +001110 Assured Forwarding (AF13) 2597 +010010 Assured Forwarding (AF21) 2597 +010100 Assured Forwarding (AF22) 2597 +010110 Assured Forwarding (AF23) 2597 +011010 Assured Forwarding (AF31) 2597 +011100 Assured Forwarding (AF32) 2597 +011110 Assured Forwarding (AF33) 2597 +100010 Assured Forwarding (AF41) 2597 +100100 Assured Forwarding (AF42) 2597 +100110 Assured Forwarding (AF43) 2597 +101110 Expedited Forwarding (EF) 2598 + + +References +========== +RFC 2474, "Definition of the Differentiated Services (DS Field) + in the IPv4 and IPv6 Headers", http://www.ietf.org/rfc/rfc2474.txt + +RFC 2475, "An Architecture for Differentiated Services", + http://www.ietf.org/rfc/rfc2475.txt + +RFC 2597, "Assured Forwarding PHB Group", http://www.ietf.org/rfc/rfc2597.txt + +RFC 3246, "An Expedited Forwarding PHB", http://www.ietf.org/rfc/rfc3246.txt + +RFC 3247, "Supplemental Information for the New Definition of the EF PHB", + http://www.ietf.org/rfc/rfc3247.txt + +RFC 3168, "The Addition of Explicit Congestion Notification (ECN) + to IP", http://www.ietf.org/rfc/rfc3168.txt + +Ethereal, http://www.ethereal.com |