Unconfigure Diffserv Dscp-Mapping Ports - Extreme Networks ExtremeWare Command Reference Manual

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PoS Commands

unconfigure diffserv dscp-mapping ports

unconfigure diffserv dscp-mapping ports <portlist>

Resets the DSCP mapping tables for the specified PoS ports to their default values.

Syntax Description

Specifies the port number(s).

Usage Guidelines

Three DSCP mapping tables are supported per SONET port. One of the tables is used in the ingress

direction and two are used for egress flows (onto the SONET link). The two egress tables are for the

congested and non-congested states, as determined by the RED algorithm (in other words, the

congested state is when the average queue length is greater than the minimum RED threshold). If RED

is not enabled on the SONET port, then the egress congested-state mapping table is not used.

The tables are very simple. In the ingress direction, the input DSCP of a packet received from the

SONET link is replaced with an output DSCP before the packet is forwarded. The replacement is

straightforward; the input DSCP is used as an index into a 64-entry table that contains the output

DSCPs associated with each of the input DSCP values. The operation is similar in the egress direction,

with the DSCP mapping occurring before the packet is transmitted onto the SONET link(s). The

mapping operation is performed after the packet has been assigned to a QoS profile. One potential use

of the DSCP mapping capability is reconciliation of varying DiffServ policies at the boundary between

autonomous systems (for example, at the boundary between two ISPs). The availability of different

tables for the congested/non-congested states is useful for marking operations that increase the drop

probability of packets during times of congestion, as discussed in the DiffServ assured forwarding (AF)

This command is currently only applicable to SONET ports.

The following command resets the DSCP mapping tables for port 1, slot 8 of a BlackDiamond switch to

their default values:

unconfigure diffserv dscp-mapping port 8:1

This command was first available in an ExtremeWare IP Technology Services Release based on

ExtremeWare Software 7.3.0 Command Reference Guide

Extremeware 7.3.0