In the last couple of blogs, we covered translation rule logic. In this blog, we will apply this logic to a gateway router configuration. Dial peer 22 below is represents an FXS port with an analog phone connected to it:
Dial-peer voice 22 pots
When the analog phone dials any destination on the PSTN, the caller ID (ANI) of the phone is represented as 11321 (calling party), not the DID number of the phone which is 212-551-1321. To remedy this situation, an outgoing translation profile will be used on the outbound POTS dial peer. The following simplified dial peer will be used to represent all outbound calling in our example:
Dial-peer voice 100 pots
The following translation rule matches on all patterns beginning with 11 and will translate the caller ID to a 10 digit caller ID matching the DID block for that site. Three of the digits have been removed from the match and replace string because the "dot" wild card cannot be used in a replace string.
Router(config)# Voice translation-rule 1
Router(cfg-translation-rule)#rule 1 /11/ /2125511/
The following translation profile uses translation-rule 1 to change the caller ID from 5 digit dialing to 10 digit dialing.
Router(config)#voice translation-profile outbound-pstn
Router(cfg-translation-profile)#translate calling 1
Translation profiles can translate calling, called, or redirect-called, or redirect-target party information. One translation profile can call 4 different translation rules, but each translation rule will be used to modify either calling, called, redirect-called, or redirect-target information. A translation profile cannot multiple translation rules that aim to modify the same information. Recall that a translation rule can include up to 15 individual rule statements providing very granular digit manipulation ability.
Be very careful when naming translation profiles. Most names defined in Cisco IOS are case sensitive. The naming of the following configuration elements in Cisco IOS are all case sensitive:
MPLS VPN VRFs (VPN Routing and Forwarding) tables
CORLists (Class of Restriction Lists used to enforce class of service in CUCME)
H.323 ID (identifiers used by H.323 terminals or gateways)
H.323 Gatekeeper Zone names
Tftpdnld environment variables
Mgcpapp dial-peer variable for MGCP controlled endpoints
class-map name (QoS)
policy-map name (QoS)
Now we will apply the translation profile to the PRI dial-peer that will be used for call routing to the PSTN:
Dial-peer voice 100 pots
Translation-profile outgoing outbound-pstn
Each dial peer can include only one outgoing and one incoming translation profile. We’ll try to have some more fun with translation rules and profiles in the next blog. If you can think of any other Cisco IOS configuration names that are case sensitive, please post them as comments to the blog. Thanks.
Tftpdnld Environmental Variables
mgcpapp – MGCP Configuration Guide
Dennis Hartmann, CCIE No. 15651, is a consultant with www.highpoint.com and author of Implementing Cisco Unified Communications Manager, Part 1. Dennis is also a lead instructor at Global Knowledge. Dennis has various certifications, including the Cisco CCVP, CCSI, CCNP, CCIP, and the Microsoft MCSE. Dennis has various specializations including unified communications, data center, routing & switching, service provider (MPLS and optical). Dennis has worked for various Fortune 500 companies, including AT&T, Sprint, Merrill Lynch, KPMG, and Cabletron Systems. He lives with his wife and children in Hopewell Junction, New York.