Dial-Peer Digit Manipulation
In the CCIE Collaboration lab, understanding dial-peers is extremely important. Lack of knowledge in this area can yield devastating results in your lab score report since they can be found in so many different sections of the exam. We must be thoroughly prepared to tackle every aspect of this technology should we be presented with it at some point.
I recently got a great question in our forums about digit manipulation within POTS dial-peers and how they interact with translation rules and profiles. I figured that since this is such an important topic, my answer to his question bears repeating so it can reach a wider audience.
Let’s begin with the simple example of dialing the number “123” from a CUCME phone. Of course, the POTS dial-peer must be created to support the desired behavior.
When this pattern is selected, all digits will be stripped automatically since they are explicitly defined. This is due to the “automatic POTS dial-peer digit strip” feature in IOS. See below for the ISDN Q.931 debug output (no Called Party Number).
Since we are not currently sending a Called Party Number, we’ll need some way to add the digits back to the string to Continue reading
