Avaya manual DSCP-to-COS Maps, Trust Modes, Multilayer Policy Implementation in the P334T-ML

Chapter 11 Avaya P330 Layer 2 Features

DSCP-to-COS Maps

DSCP-to-COS maps set the frame 802.1p priority according to the DSCP priority value. For each DSCP value, the map contains a corresponding COS. The map changes the COS value for frames that match an active Access List rule with a “permit” action.

The following conditions apply to DSCP-to-COS maps:

•DSCP-to-COS maps are defined within the Policy Lists.

•Only packets that match an Access List rule with a “permit” action can be modified based on a DSCP-to-COS map.

•Actions supported per DSCP include: Fwd 0, Fwd1 ....Fwd7, Forward no change.

Trust Modes

P334T-ML supports the following Trust Mode values:

•“untrusted” — forwards the packet with 802.1p priority=0.

•“trust-cos” — forwards the packet with its original 802.1p priority (default).

•“trust-dscp” — forwards the packet with an 802.1p priority obtained from the DSCP-to-COS mapping table.

Multilayer Policy Implementation in the P334T-ML

Each P334T-ML can store up to 20 Policy Lists. These lists consist of: Access Lists, DSCP-to-COS Maps, and Trust Modes.

Avaya P334T-ML supports two policy types:

•“Router” – the switch enforces the active Policy List only on routed packets. This applies to P334T-ML switches in “Router” device mode.

•“All” – the switch enforces the active Policy List on all packets that enter through the Fast Ethernet ports. This applies to P334T-ML switches in “Router” or “Layer2” device mode.

“All” is the policy type available when the P334T-ML device mode is “Layer2.”

There can be only one active Policy List per module with either policy type. The following conditions apply to Policy Lists:

•Policy Lists can be defined in the “switch” context when the P334T-ML is in “Layer2” device-mode or in the “router” context when the P334T-ML is in “Router” device-mode.

•Policy Lists are shared by Layer 2 and Layer 3 applications.

•The maximum number of rules per L3 Access List is 9999 when the policy type is “Router”. If the Policy List is to be applied to Layer 2 as well – policy type “all”, the maximum number of rules per list is 254.

110 Avaya P334T-ML User’s Guide