Beta Draft Confidential
About ATM Logical Ports
ATM OPTimum Cell Trunk
ATM Services Configuration Guide for CBX 3500, CBX 500, GX 550, and B-STDX 9000
1/19/05
2-9
Configuring the OPTimum Trunk for VPCs
PVC and SVC VPCs and Internet Protocol (IP)-related connections can traverse
OPTimum trunks. The following section describes each configuration.
PVC/SVC VPC Connections
The VPC VPI start and VPC VPI stop values define the range of VPIs to be used for
all connection-based VPC circuits (that is, PVC, SVC, and SPVC) over this
OPTimum trunk.
The valid range of VPI values depends on the number of valid VPI bits you set for the
ATM UNI feeder port (see
). The specified range may not
overlap the ranges specified for OPTimum trunk IP connections.
Example
Assume that the following conditions are in place:
•
The number of valid VPI bits set from the ATM UNI feeder port is 4.
•
The VPI value is set to 0.
Using these assumptions, if you want to configure two VPIs on the OPTimum trunk to
support PVC, SVC, or SPVC VPC circuits, you could specify a VPC VPI start of 1
and a VPC VCI stop of 2.
IP-related Connections
You can configure label switch paths (LSPs) over OPTimum cell trunks on
B-STDX 9000, CBX 3500, and CBX 500 switches. This is done differently,
depending on the switch:
•
On CBX 3500 and CBX 500 switches, IP automatically assigns a permanent
virtual path (PVP) to each LSP crossing an OPTimum trunk. These point-to-point
PVPs carry LSP traffic in both directions, which reduces the number of paths
required to interconnect switches in two given clusters.
•
On B-STDX 9000 switches, IP assigns a VCC to each LSP crossing an OPTimum
trunk.
Note – The network that interfaces with the OPTimum trunk must be configured to
accept circuits with this VPI and any of its valid VCIs. To accomplish this, create a
PVC in the interfacing network using this VPI and define the PVC circuit type as VPC
(see
Summary of Contents for CBX 3500
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