Technical Documentation

Defining CoS Rewrite Rules (J-Web Procedure)

You can use the J-Web interface to define CoS rewrite rules. Use the rewrite rules to alter the CoS values in outgoing packets to meet the requirements of the targeted peer. A rewrite rule examines the forwarding class and loss priority of a packet and sets its bits to a corresponding value specified in the rule.

To define rewrite rules:

  1. Select Configure > Class of Service > Rewrite Rules.
  2. Click one:
    • Add—Adds a rewrite rule. Enter information into the rewrite rule page as described in Table 1.
    • Edit—Modifies an existing rewrite rule. Enter information into the rewrite rule page as described in Table 1.
    • Delete—Deletes an existing rewrite rule.

Table 1: Rewrite Rules Configuration Page Summary

Field

Function

Your Action

Rewrite Rule Name

Specifies the name for the rewrite rule.

To name a rule, type the name—for example, rewrite-dscps.

Rewrite rule type

Specifies the type of rewrite rule: dscp, ieee-802.1, or inet-precedence.

Select a value from the list.

Code Point Mapping

Rewrites outgoing CoS values of a packet based on the forwarding class and loss priority.

Allows you to remove a code point mapping entry.

To configure a CoS value assignment, follow these steps:

To add a code point mapping:

  1. Click Add.
  2. Select the code point.
  3. Select a forwarding class from the following list:
    • expedited-forwarding—Provides low loss, low delay, low jitter, assured bandwidth, and end-to-end service. Packets can be forwarded out of sequence or dropped.
    • best-effort—Provides no special CoS handling of packets. Typically, RED drop profile is aggressive and no loss priority is defined.
    • assured-forwarding—Provides high assurance for packets within the specified service profile. Excess packets are dropped.
    • network-control—Packets can be delayed but not dropped.
  4. Select the loss priority.

    To assign a loss priority, select one:

    • high—Packet has a high loss priority.
    • low—Packet has a low loss priority.

To edit an existing code point mapping, select it and click Edit.

To remove a code point mapping entry, select it and click Remove.

Published: 2010-02-21