Users Guide

Layer 2 Switching Commands 737
DiffServ
Standard IP-based networks are designed to provide “best effort” data delivery
service. Best effort service implies that the network delivers the data in a
timely fashion, although there is no guarantee that it will meet the latency or
bandwidth requirements. During times of congestion, packets may be
delayed, sent sporadically, or dropped. For typical Internet applications, such
as email and file transfer, a slight degradation in service is acceptable and in
many cases unnoticeable. Conversely, any degradation of service has
undesirable effects on applications with strict timing requirements, such as
voice or multimedia.
Diffserv allows the network operator to classify and apply a distinguished
service to traffic based on a number of criteria. The distinguished service can
meter traffic and apply per hop behavior based upon the bandwidth
utilization and burstiness of traffic. In addition, preferential drop
characteristics can be configured in support of an assured forwarding
capability such that TCP clients are informed if they exceed the switch
buffering limits.
assign-queue
Use the assign-queue command in Policy-Class-Map Configuration mode to
modify the queue ID to which the associated traffic stream is assigned.
Syntax
assign-queue queueid
• queueid — Specifies a valid queue ID. (Range: integer from 0–6.)
Default Configuration
This command has no default configuration.
Command Mode
Policy-Class-Map Configuration mode