[This is pre-release documentation and subject to change in future releases. This topic's current status is: Milestone-Ready]

Topic Last Modified: 2010-07-06

Communications Server 2010 Enterprise Voice requires that all dial strings be normalized to E.164 format for the purpose of performing reverse number lookup (RNL). The trunk peer (that is, the associated gateway, PBX, or SIP trunk) may require that numbers be in a local dialing format. To translate numbers from E.164 format to a local dialing format, you can define one or more translation rules to manipulate the Request URI before routing it to the trunk peer. For example, you could write a translation rule to remove +44 from the beginning of a dial string and replace it with 0144.

By performing outbound route translation on the server, you can reduce the configuration requirements on each individual trunk peer to manipulate phone numbers into a local dialing format. In planning which and how many gateways to associate with a given Mediation Server cluster, it may prove useful to group trunk peers with similar local dialing requirements so as to reduce the number of required translation rules and the time it takes to write them.

The ability to associate one or more translation rules with an Enterprise Voice trunk configuration is intended to be used as an alternative to configuring translation rules on the trunk peer. Do not associate translation rules with an Enterprise Voice trunk configuration if you have configured translation rules on the trunk peer because the two rules might conflict.

Example Translation Rules

The following examples of translation rules show how you can develop rules on the server to perform translation of numbers from E.164 format to a local format for the trunk peer.

For information about how to implement translation rules, see “Defining Translation Rules” in the Operations documentation.

Description Starting Digits Length Digits to Remove Digits to Add Matching Pattern Translation Example

Normal long distance dialing in US

(strip out the ‘+’)


Exactly 12





+14255551010 becomes 14255551010

US International long-distance dialing

(strip out ‘+’ and add 011)


At least 11





+441235551010 becomes 011441235551010