Nortel Networks 8000 - Manual (Page 222)

Nortel Secure Router 8000 Series
Configuration -WAN Access 7 LAPB and X.25 configuration
x25 response calling-address
The calling DTE address is carried when a call response packet is sent.
Step 12 Run:
x25 default-protocol protocol-type
The command specifies the default upper layer protocol.
In the default situation:
• The timer resetting delay at DTE side is 180 seconds, and the delay at the DCE side is 60
seconds.
• The delay of calling request send timer at DTE side is 200 seconds, and the delay at the
DCE side is 180 seconds.
• The delay of resetting request timer at DTE side is 180 seconds, and the delay at the
DCE side is 60 seconds.
• The delay of clearing request sending timer at DTE side is 180 seconds, and the delay at
the DCE side is 60 seconds.
• The upper layer protocol carried by X.25 is IP.
—End
In certain special network environments, it is necessary for you to configure some
supplementary X.25 parameters.
• Configuring the Delay of X.25 Layer 3 Timer
The X.25 protocol defines a series of timers to facilitate its procedure. After X.25 sends a
control packet and does not receive the response before the timeout of the corresponding
timer, the X.25 protocol takes the corresponding measure to handle this abnormal event.
Table 7-2 shows the names and corresponding procedures of these timers.
Table 7-2 X.25 layer 3 timer
Procedure name Timer name
DTE side DCE side
Restart T20 T10
Call T21 T11
Restore T22 T12
Clear T23 T13
Register T28 -
In the table, T28 is the timer of "sending register request", and is defined only at the DTE side.
You use this to dynamically apply or stop the selective services in the network. Its reference
value is 300 seconds and cannot be modified. •
• Configuring the Attribute Related to X.25 Address
Issue 5.3 (30 March 2009) Nortel Networks Inc. 7-19