gtpc1m2vTransmission Control Protocol/Internet Protocol

Quality of Service

The TCP/IP network services database uses quality of service (QoS) information to provide differentiated services for outbound messages, allowing the TPF system to mark outbound packets for each application to determine per hop behavior for routers.

The IP architecture, defined by Request for Comments (RFC) 791, originally defined a type of service (TOS) field in the IP header. This TOS field was redefined as a differentiated services field by RFC 2475. Each outbound TPF message has a differentiated services codepoint value that specifies the network priority. You can define this differentiated codepoint value for each application defined in the TCP/IP network services database by specifying the TOS parameter. You can also define a default value in keypoint 2 (CTK2) by using the IPTOS parameter on the SNAKEY macro. If you do not specify the TOS parameter for a particular application, the TPF system will use the default value defined in CTK2. If the outbound message is from a RAW socket, the TPF system will use the value of the IPTOS parameter unless it has already been filled in by the application. See TPF ACF/SNA Network Generation for more information about the SNAKEY macro.

See the following RFC documents for more information about the quality of service (QoS) architectures supported by the TPF system:

Go to http://www.ietf.org for more information about these RFCs and any related extensions.