Connection Routing Groups; Table 1-1 Routing Group Configuration Example - Cisco BPX-BXM-155-8DX Installation And Configuration Manual

Chapter 1 The BPX Switch: Functional Overview
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The system software uses these criteria when it establishes an automatic route for a connection:
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When a node reroutes a connection, it uses these criteria and also looks at the priority that has been
assigned and any user-configured routing restrictions. The node analyzes trunk loading to determine the
number of cells or packets the network can successfully deliver. Within these loading limits, the node
can calculate the maximum combination allowed on a network trunk of each type of connection:
synchronous data, ATM traffic, Frame Relay data, multimedia data, voice, and compressed voice.
Network-wide T3, E3, OC-3, or OC-12 connections are supported between BPX switches terminating
ATM user devices on the BPX switch UNI ports. These connections are routed using the virtual path
and/or virtual circuit addressing fields in the ATM cell header.
Narrowband connections can be routed over high-speed ATM backbone networks built on BPX
broadband switches. FastPacket addresses are translated into ATM cell addresses that are then used to
route the connections between BPX switches, and to ATM networks with mixed vendor ATM switches.
Routing algorithms select broadband links only, avoiding narrowband nodes that could create a choke
point.

Connection Routing Groups

The re-routing mechanism ensures that connections are presorted in order of cell loading when they are
added. Each routing group contains connections with loading in a particular range. The group
containing the connections with the largest cell loadings is rerouted first, and subsequent groups are
then rerouted on down to the last group that contains connections with the smallest cell loadings.
There are three configurable parameters for configuring the rerouting groups:
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You configure the three routing group parameters by using the cnfcmparm command.
For example, there might be 10 groups, with the starting load size of the first group at 50, and the
incremental load size of each succeeding group being 10 cells. Then group 0 would contain all
connections requiring 0–59 cell load units, group 1 would contain all connections requiring from 60–69
cell load units, on up through group 9 which would contain all connections requiring 140 or more cell
load units.
Table 1-1
Routing group
0
1
2
Release 9.3.0, Part Number 78-10674-01 Rev. D0, July 2001
Alternate Routing
The system software automatically reroutes a failed connection.
Selects the most direct route between two nodes.
Selects unloaded lines that can handle the increased traffic of additional connections.
Takes into consideration user-configured connection restrictions (for example whether or not the
connection is restricted to terrestrial lines or can include satellite hops or routes configured for
route diversity).
Total number of rerouting groups
Starting load size of first group
Load size range of each group
Routing Group Configuration Example
Connection cell loading
0–59
60–69
70–79
Cisco BPX 8600 Series Installation and Configuration
Switch Software Description
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