Avaya P332G-ML manual Simple Router Redundancy Protocol Srrp, Policy Quality of Service QoS

Chapter 1 Overview

In VRRP, two or more physical routers can be associated with a virtual router, thus achieving the extreme reliability inherent in the SAFER architecture.

In a VRRP environment, host stations interact with the virtual router. They are not aware that this router is a virtual router, and they are not affected when a new router takes over the role of master router. This makes VRRP fully interoperable with every host station.

VRRP can be activated on an interface using a single command while allowing for the necessary fine-tuning of the many VRRP parameters. For a detailed description of VRRP, refer to VRRP standards and published literature.

Simple Router Redundancy Protocol (SRRP)

P332G-ML IP SRRP redundancy capabilities provide automatic backup Layer 3 switching for IP stations. P332G-ML units can be configured to back each other up so that if one fails the other will take over its forwarding functions. The backup P332G-ML is not idle. As long as both P332G-ML units are functional, traffic is shared between them. The P332G-ML modules can be in the same P330 stack or in different, connected, P330 stacks. The P332G-ML can back up another P332G-ML unit or any other router.

A P332G-ML unit configured to back up another unit monitors the other’s status by polling it at configured intervals, and automatically detects when the other fails and when it becomes functional again. When detecting a failure, the backup P332G-ML sends a gratuitous ARP message that causes all stations to send their IP traffic to the backup P332G-ML MAC address instead of the failed unit MAC address. As long as it is an active backup resulting from the failure of the main unit, the backup P332G- ML answers ARP requests for the main unit, providing its own MAC address.

Policy – Quality of Service (QoS)

The P332G-ML supports QoS by using multiple priority levels and IEEE 802.1p priority tagging to ensure that data and voice receive the necessary levels of service.

The P332G-ML can enforce policy on routed packets (per packet), according to four criteria:

•The IEEE 802.1p priority tag in the incoming packet.

•The Diff-Serv byte (TOS field) in the IP header of the incoming packet.

•Matching the packet’s source or destination IP address to the configured priority policy.

•Whether the packet source or destination TCP/UDP port number falls within a pre-defined range.

The P332G-ML can enforce centralized network policies using the CajunRules central policy management application.

8 P332G-ML User’s Guide