Setup guide

C-5
Cisco 6400 Software Setup Guide
OL-1183-04
AppendixC Optimizing the Number of Virtual Connections on the Cisco 6400
Guidelines for Maximizing the Number of Virtual Connections
Using Automatic Determination of the Minimum ITT Block Size
The NSP can automatically track the size of the required ITT block as virtual connections are created
and deleted. The required block size is stored in the running configuration and is used to optimally
allocate ITT resources after an interface flap. When you enter the copy system:running-config
nvram:startup-config EXEC command, the required block size is also saved to the startup
configuration, so that optimal ITT allocation occurs at the next reload.
Note This functionality is available in Cisco IOS Release 12.1(4)DB and later releases.
To enable automatic determination of the minimum ITT block size, use the following command in global
configuration mode:
Note The no version of the atm input-xlate-table autominblock command deletes all manually or
automatically configured minblock keyword entries, except the entries that include the force keyword.
Example
In the following example, the system determines the optimal ITT block size for all ATM port and VPI
combinations in the configuration. The system automatically inserts the minblock keyword version of
the command for every ATM port and VPI combination, except when manually entered with the force
keyword.
!
atm input-xlate-table autominblock
!
interface atm 1/0/0
atm input-xlate-table minblock vpi 0 1024 force
atm input-xlate-table minblock vpi 1 2048 force
!
Verifying Automatic Determination of the Minimum ITT Block Size
To verify that you successfully enabled automatic determination of the minimum ITT block size, use the
more system:running-config EXEC command. Make sure that the
atminput-xlate-tableautominblock command appears in the running configuration.
To verify that the minimum block size is allocated globally, use the show atm input-xlate-table inuse
EXEC command. Check the Size field for every ATM port and VPI on which PVCs or Soft PVC source
legs are configured.
Command Purpose
Switch(config)# atm input-xlate-table autominblock
Enables the system to determine the optimal ITT block size for
every ATM port and VPI on which PVCs or Soft PVC source
legs are configured. Automatically inserts the minblock
keyword version of the command with the optimal block size
for each ATM port and VPI combination.