Allied Telesis AT-SBx8, Installation Manual

Page: 60 / 248

Chapter 3: AT-SBx81CFC400 Controller Fabric Card
60
Dual Controller Cards
You may install either one or two controller cards in the chassis. Here are
the advantages to having two controller cards in the chassis.
 Having a second controller card improves the performance of the
chassis by increasing the backplane bandwidth for the Ethernet
line cards. Two controller cards increase the bandwidth for each
slot to up to 80 Gbps.

Installing a second controller card adds redundancy. If a controller
card fails in the chassis, the second card enables the Ethernet line
cards to maintain network operations.
Here are the guidelines to dual controller cards:
 One card operates as the active master card and the other as the
standby master card. You can determine the state of a controller
card by the M/S LED. For information, refer to “SYS Status LEDs”
on page 62.
 The controller cards automatically determine their states when the
chassis is powered on or reset. The card that boots up first is
designated as the active master card. If both cards boot up at the
same time, the card in slot 5 is designated as the active master
card.
 All management sessions have to be conducted through the active
controller card.

You have to use the Console RS-232 port on the active controller
card to establish a local management session with the chassis.
 When the chassis is powered on or reset, the two controller cards
perform an initialization process, part of which involves the inactive
card synchronizing its management files with the active card.
During this phase of the initialization process, which may take
several minutes, the inactive card does not participate with the
active card in forwarding traffic over the backplane and its SFP+
slots are nonfunctional. After the inactive card has finished the
initialization process, it joins with the active card in forwarding
traffic on the backplane and activates its SFP+ slots. For more
information, refer to “Monitoring the Initialization Process” on
page 187.
Two controller cards provide an active/active architecture. The packet
processors on both controller cards are fully utilized, doubling the
available backplane bandwidth to up to 80Gbps per line card slot.