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Dual homing – ADC AVIDIA SWD4573I1 User Manual

Page 55

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Chapter 3: Applications and Configuration Overview

Avidia System Configuration and Management User Manual

29

Dual Homing

Through dual homing, a second network interface (DS1, DS3 or OC3 line card) is used in the
Avidia system and provides support that includes:

backup or redundant PVCs with the same destination

static load sharing where traffic is directed separately to a primary and to a secondary
line card, increasing the amount of traffic that you can send through the system
(see

page 30

)

See

page 31

for information about applying Quality of Service to traffic that is assigned to dual

homing configurations.

When setting up a system for dual homing, one line card is a primary line card and the second
line card is a secondary or backup line card. In an Avidia 8000 system, you can install the line
cards into slot 11 and slot 12. The two line card slots are essentially symmetric. At any point,
only one of the two line cards will provide cell bus clocking. Configure ATM VPCs and VCCs
to the line card that you choose as primary and configure the backup VPCs and VCCs to the
second line card.

In an Avidia 3000 system, you can install the line cards into slot 2 and slot 3. The line card
in slot 2 provides cell bus clocking and must be in the slot when an Avidia 3000 system
is initialized (booted). When there is a failure of the line card in slot two, cell bus clocking
switches to slot 1. Configure ATM VPCs and VCCs to the line card that you choose as primary
and configure the backup VPCs and VCCs to the second line card.

Redundancy is another feature of Avidia systems that uses two line cards. Redundancy
provides backup at a card level where dual homing provides backup at a PVC level (VPCs and
VCCs). See

page 32

for more information about redundancy. You can implement both

redundancy and dual homing concurrently in an Avidia system. You must, however, carefully
plan traffic management and QoS to efficiently run the network. See

page 30

for information

about traffic management.