How Resources Are Managed; Vsi Slave Redundancy (Hot Slave Redundancy) - Cisco BPX-BXM-155-8DX Installation And Configuration Manual

Chapter 23 Configuring BXM Virtual Switch Interfaces

How Resources are Managed

VSI LCNs are used for setting up the following management channels:
•
•
•
Intershelf blind channels are used in cluster configuration for communication between slaves on both
sides of a trunk between two switches in the same cluster node.
The maximum number of slaves in a switch is 12. Therefore a maximum of 11 LCNs are necessary to
connect a slave to all other slaves in the node. This set of LCNs is allocated from the reserved range of
LCNs.
If a controller is attached to a shelf, master-slave connections are set up between the controller port and
each of the slaves in the shelf.
For each slave that is not directly connected, the master-slave control VC consists of two legs:
•
•
For the slave that is directly connected to the controller, the master-slave control VC consists of a single
leg between the controller port and the slave. Therefore, 12 LCNs are needed in the directly-connected
slave, and 1 LCN in each of the other slaves in the node for each controller attached to the shelf.
These LCNs will be allocated from the Automatic Routing Management pool. This pool is used by
Automatic Routing Management to allocate LCNs for connections and networking channels.
For a given slave the number of VSI management LCNs required from the common pool is:

VSI Slave Redundancy (Hot Slave Redundancy)

The function of the slave hot standby is to preprogram the slave standby card the same as the active card
so that when the active card fails, the slave card switch over operation can be done quickly (within
250 ms). Without the VSI portion, the BXM card already provided the hot standby mechanism by
duplicating CommBus (internal BPX protocol) messages from BCC to standby BXM card.
Because the master VSI controller does not recognize the standby slave card, the active slave card
forwards VSI messages it received from the Master VSI controller to the standby Slave VSI card.
Also, when the standby slave VSI card is first started (either by having been inserted into the slot, or if
you issue the
VSI messages it had received from the Master VSI controller card to the standby Slave VSI controller
card.
In summary, these are the hot standby operations between active and standby card:
1.
Release 9.3.0, Part Number 78-10674-01 Rev. D0, July 2001
inter-slave
master-slave
intershelf blind channels
One leg from the VSI master to the backplane, through the directly connected slave
A second leg from the backplane to the corresponding VSI slave.
n X 12 + m
where:
n is the number of controllers attached to this slave
m is the number of controllers in the switch directly attached to other slaves
command from the CLI console), the active slave VSI card needs to forward all
addyred
CommBus messages are duplicated to standby slave VSI card by the BCC.
Operation 1 does not need to implement because it had been done by the BCC.
VSI Master and Slave Redundancy
Cisco BPX 8600 Series Installation and Configuration
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