HPE FlexNetwork MSR Series Comware 5 Layer 2 - Wan Access Configuration Guide

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Configuring X.25 interface supplementary parameters
Introduction to X.25 interface supplementary parameters
It is necessary to configure certain supplementary X.25 parameters in some special network
environments. The following sections are related to the following supplementary parameters.
• X.25 layer 3 delay timer
X.25 protocol defines a series of timers to facilitate its procedure. After X.25 sends a control
message, if it does not receive the response before the timer expires, X.25 protocol will take
measures to handle this abnormal event. Table 5 lists the names a
nd procedures of these
timers.
Table 5 X.25 Layer 3 timer
Procedure name
Timer name
DTE side DCE side
Restart T20 T10
Call T21 T11
Reset T22 T12
Clear T23 T13
Register T28 N/A
T28 is a "Registration request sending" timer which is only defined on DTE for dynamically
requesting the network for optional services or stopping these services. Its default value is 300
seconds, which cannot be changed.
• Attributes related to X.25 address
To establish an SVC with a call, X.25 address is needed, which adopts the address format
specified in ITU-T Recommendation X.121. An X.121 address is a string of 1 to 15 digits. Some
attributes related to X.121 address are as follows:
• Alias of interface
When an X.25 call is forwarded across multiple networks, different networks will likely make
some modifications on the called address as needed, such as adding or deleting the prefix. In
such cases, the destination address of a call that reaches X.25 interface might be inconsistent
with X.121 address of the destination interface (because the destination address of this call is
modified within the network); still the interface should accept this call. For this purpose, one or
more alias names must be specified for this interface.
To meet the requirements of different networks, X.25 defines nine match types and their
relevant alias string formats, as shown in Table 6.
Table 6
Alias match modes and meanings
Matching mode Description Example
free
Free matching, the alias string is
in the form of 1234.
"1234" will match 561234,
1234567 and 956123478, but
will not match 12354.
free-ext
Extended free matching, in
which the alias string is in the
form of …1234..
"…1234 .." will match
678123459, but will not match
68123459, 67812345 and
6781234591.
left
Left-most matching mode, in
which the alias string is in the
form of $1234.
"$1234" will match 1234567 and
12346790, but will not match
3123478 and 123784.

HPE FlexNetwork MSR Series Specifications

General

Brand	HPE
Model	FlexNetwork MSR Series
Category	Network Router
Language	English