Cisco BPX 8650, Installation And Configuration Manual

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Cisco BPX 8600 Series Installation and Configuration
Release 9.3.30, Part Number 78-12907-01 Rev. E0, May 2005
Chapter 23 Configuring BXM Virtual Switch Interface
VSI Master and Slave Redundancy
Master Redundancy
You add a VSI controller, such as an MPLS or PNNI controller by using the addshelf command with the
VSI option. The VSI option of the addshelf command identifies the VSI controllers and distinguishes
them from interface shelves (feeders).
The VSI controllers are allocated a partition of the switch resources. VSI controllers manage their
partition through the VSI interface.
The controllers run the VSI master. The VSI master entity interacts with the VSI slave running on the
BXMs through the VSI interface to set up VSI connections using the resources in the partition assigned
to the controller.
Two controllers intended to be used in a redundant configuration must specify the same partition when
added to the node with the
addshelf command.
When a controller is added to the node, switch software will set up the infrastructure so that the
controllers can communicate with the slaves in the node. The VSI entities decide how and when to use
these communication channels.
In addition, the controllers require a communication channel between them. This channel could be
in-band or out-of-band. When a controller is added to the switch, switch software will send controller
information to the slaves. This information is advertised to all the controllers in the partition. The
controllers may decide to use this information to set up an intermaster channel. Alternatively, the
controllers may use an out-of-band channel to communicate.
The maximum number of controllers that can be attached to a given node is limited by the maximum
number of feeders that can be attached to a BPX hub. The total number of interface shelves (feeders) and
controllers is 16.
Slave Redundancy
Prior to Release 9.2, hot standby functionality was supported only for Automatic Routing Management
connections. This was accomplished by the BCC keeping both the active and standby cards in sync with
respect to all configuration, including all connections set up by the BCC. However, the BCC does not
participate in, nor is it aware of, the VSI connections that are set up independently by the VSI controllers.
Therefore, the task of keeping the redundant card in a hot standby state (for all the VSI connections) is
the responsibility of the two redundant pair slaves. This is accomplished by a bulk update (on the standby
slave) of the existing connections at the time that (line and trunk) Y-redundancy is added, as well as an
incremental update of all subsequent connections.
The hot standby slave redundancy feature enables the redundant card to fully duplicate all VSI
connections on the active card, and to be ready for operation on switchover. On bringup, the redundant
card initiates a bulk retrieval of connections from the active card for fast sync-up. Subsequently, the
active card updates the redundant card on a real-time basis.
The VSI Slave Hot Standby Redundancy feature provides the capability for the slave standby card to be
preprogrammed the same as the active card so that when the active card fails, the slave card switchover
operation can be done quickly (within 250 ms). Without the VSI portion, the BXM card already provided
the hot standby mechanism by duplicating CommBus messages from the BCC to the standby BXM card.
The following sections describe some of the communication between the switch software and firmware
to support VSI master and slave redundancy.