Avaya 580 - Manual (Page 34)

1-10 User Guide for the Avaya P580 and P882 Multiservice Switches, v6.1
Chapter 1
Redundant
Supervisor The redundant supervisor module is an auxiliary (standby) supervisor
module that acts as a fault-tolerant supervisor in the event that the active
supervisor fails. The redundant supervisor provides a seamless solution to
switch failure. Once the redundant supervisor is installed, loaded with the
same software version as the active supervisor, and synchronized, it is ready
to act as a backup to the active supervisor. If the active supervisor does fail,
the redundant module quickly assumes control with the least possible effect
on network operation. No user intervention is required for the CPU module
switchover. The management view is accessible without changing IP or
MAC addresses.
For more information about the redundant supervisor module, see
Chapter 10 , “ Configuring Redundancy Options .”
Media Modules
The layer 2 and layer 3 media modules implement wire speed routing and
bridging in ASICs. The routing and bridging ASICs can process 1.5 million
packets per second of minimum-sized Ethernet frames.
* Note: All layer 3 modules interoperate with layer 2 modules.
The ATM Uplink module provides LAN Emulation (LANE) connectivity
over an ATM network and supports RFC 1483.
Bridging and routing are performed on the input side of each media module.
Frames whose destination Media Access Control (MAC) address is on the
same Virtual LAN (VLAN) as the interface on which they arrived are
bridged. Frames that are going from one VLAN to another are routed. Some
frames are both bridged and routed, as is the case with multicast.
The media modules’ features include:
■
Onboard routing—See “ Routing Overview ” later in this chapter
for more information about the onboard routing capability of the
media modules.
■
IEEE 802.3x full-duplex flow control—This allows the switch
ports to send a pause command before input buffers overflow. Half-
duplex ports support active backpressure (jamming).
■
VLAN trunking or non-tagged access modes —This allows the
switch ports to interoperate with popular tagged trunking schemes
used by other vendors.
■
Priority Queuing and Class of Service—These features allow you
to prioritize traffic between particular stations or sets of stations to
support jitter-sensitive applications.