Voice Translation in Cisco GW

Voice translation rules have tripped up many an engineer, especially when troubleshooting an existing router that you may not have installed.  In those situations, it can be easy to misunderstand the subtleties of voice translation rules when quickly reviewing a production configuration.

There are some wildcard and their definition in below table;

.                  >> Any single digit

[0-9]          >> Any range of characters

*                 >> Modifier—match none or more occurrences

+                 >> Modifier—match one or more occurrences

?                 >> Modifier—match none or one occurrence

.*                >> Any digit followed by anything, including null.

.+                >> Any digit followed by anything, except null.

^$               >> For null

How to start to configure router;

cisco_5350(config)#voice translation-rule 1

cisco_5350 (cfg-translation-rule)#rule 1 /905/ /B020/

#matches first occurrence (905) anywhere in number and convert to second occurrence.

You can check test result like this;

cisco_5350#test voice translation-rule 1 905434949

Matched with rule 1

Original number: 905434949    Translated number: B020434949

Also, you can set rule for 905 at the start/end of number;

cisco_5350 (config)#voice translation-rule 2

cisco_5350 (cfg-translation-rule)#rule 2 /^905/ /B020/        #if number start with 905, it will be replaced with B020

Example:

cisco_5350#test voice translation-rule 2 905434949

Matched with rule 2

Original number: 905434949    Translated number: B020434949

cisco_5350#test voice translation-rule 2 434905949

905434949 Didn’t match with any of rules

cisco_5350 (config)#voice translation-rule 3

cisco_5350 (cfg-translation-rule)#rule 3 /905$/ /B020/

#if number just matched with 905, it will be replaced with B020

Example:

cisco_5350#test voice translation-rule 3 905434949
905434949 Didn’t match with any of rules

cisco_5350#test voice translation-rule 3 434949905
Matched with rule 3
Original number: 434949905    Translated number: 434949B020

Number Slicing

In this method, you can slice the number into smaller parts,

manipulate each part and then you can put the number back again.

Template;

/ (x\) y\ (z\) /  / a \1 \2 /

Split the matched number into three sets like x, y, and z.

The backward slash (\) indicates the where to slice up the number.

The brackets () indicate which sets you want to reuse in the replacement pattern.

The a represents additional digits to insert into the replacement number.

Set 1 inherits the value of x.

Set 2 inherits the value of z.

y will be ignored.

Result: axz

Example;

cisco_5350(config)#voice translation-rule 1
cisco_5350(cfg-translation-rule)#rule 1 /^\(55\)8\(66\)$/ /8\1\2/

Set 1: 55
Set 2: 66
Ignore: 8

cisco_5350#test voice translation-rule 1 55866
Matched with rule 1
Original number: 55866    Translated number: 85566

cisco_5350#test voice translation-rule 1 12345
No match.  The match pattern is not satisfied.

cisco_5350#test voice translation-rule 1 55867
No match.  The match pattern is not satisfied.

cisco_5350#test voice translation-rule 1 55466
No match.  The match pattern is not satisfied.

Blocking Call

rule 1 reject /^900/

cisco_5350#test voice translation-rule 10 9005551212
Call blocked by rule 1

Number Type and Plan

You can restrict matches to particular number or plan types. Also, you can alter the replacement plan or type.

In this example, if a number starts with “4” and the type is “national”, the rule adds “90” as a prefix.

If the type is “international”, the rule adds “900” as the prefix.

cisco_5350 (config)#voice translation-rule 7
cisco_5350(cfg-translation-rule)#rule 1 /^4/ /904/ type national national
cisco_5350(cfg-translation-rule)#rule 2 /^4/ /9004/ type international international

cisco_5350#test voice translation-rule 7 493456567 type national

Matched with rule 1
Original number: 493456567      Translated number: 90493456567
Original number type: national  Translated number type: national
Original number plan: none      Translated number plan: none

cisco_5350#test voice translation-rule 7 493456567 type international

Matched with rule 2
Original number: 493456567              Translated number: 900493456567
Original number type: international     Translated number type: international
Original number plan: none              Translated number plan: none

This is useful when telephone companies (Telcos) remove access codes on national and international numbers.

You can add the correct prefix with the number type as a basis.

This example changes the number type and plan.

cisco_5350 (config)#voice translation-rule 8
cisco_5350(cfg-translation-rule)#rule 1 /^2\(…$\)/ /01779345\1/ type unknown national plan unknown isdn

This rule matches any four-digit number that starts with “2”. The rule removes the “2”,

adds the number “01779345” as a prefix, and sets the plan to “isdn” and the type to “national”.

cisco_5350#test voice translation-rule 8 2001 type unknown plan unknown
Matched with rule 1
Original number: 2001   Translated number: 01779345001
Original number type: unknown   Translated number type: national
Original number plan: unknown   Translated number plan: isdn

Please do not hesitate to ask any question about voice translation with using my e-mail.