Tag Switching 9-11
Tag Switching Resource Configuration Parameters
Tag Switching Resource Configuration Parameters
This section describes resource partitioning for tag switching. It includes the following:
• Summary
• Configuring VSI LCNS
• Useful Default Allocations
• Details of More Rigorous Allocations
Summary
Most tag switching configuration, including the provisioning of connections, is performed directly
by the Tag Switch Controller. This is discussed separately; refer to the Tag Switching for the Cisco
7500/7200 Series Routers documentation. Configuration for tag switching on the BPX 8650 itself,
consists of basic VSI configuration, including resource partitioning.
The following items need to be configured or checked on the BPX 8650:
• Partitioning
On each interface (port or trunk) on the BXM cards used for tag switching, two sets of resources
must be divided up between traditional PVC connections and tag switching connections. The
traditional PVC connections are configured directly on the BPX platform, and tag switching
connections are set up by the TSC using the VSI. The following resources are partitioned on each
interface:
— Bandwidth
— Connections
As with all ATM switches, the BPX switch supports up to a specified number of connections.
On the BPX switch, the number of connections supported depends on the number of port/trunk
cards installed. On each interface, space for connections is divided up between traditional BPX
switch permanent virtual circuit (PVC) connections, and Tag Switching VCs (TVCs). The details
of connection partitioning using the cnfrsrc command are discussed later in this section.
• Queues for Tag Switching traffic
These should be automatically configured correctly, but it is possible to change the configuration
manually. Consequently, the configuration of the queues should be checked as part of the process
of enabling tag switching. Configuration of these parameters using the cnfqbin command is
discussed later in this chapter.
• VSI Control Interface
A trunk must be enabled as VSI control interface, to allow a TSC to be connected. This is done
using the addshelf command and selecting the VSI option.
