Well written, I was actually having the same issues but it was related to Codec negotiation, so my PSTN site is using a CP-7961 and noticed that my Dial-peer on the PSTN router was using ilbc, and this codec is not supported on these phones, http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cuipph/7962g_7961g_7961g-ge_7942g_7941g_7941g-ge/8_0/english/administration/guide/62adm80/62614241trb.html
About the Author:
Andres Sarmiento, CCIE # 53520 (Collaboration)
With more than 13 years of experience, Andres is specialized in the Unified Communications and Collaboration technologies. Consulted for several companies in South Florida, also Financial Institutions on behalf of Cisco Systems. Andres has been involved in high-profile implementations including Cisco technologies; such as Data Center, UC & Collaboration, Contact Center Express, Routing & Switching, Security and Hosted IPT Service provider infrastructures.
Many times errors come unnoticed. Particularly when working under a timed setting with finite number of tasks to complete, like the main CCIE Voice Lab, or even a mock/practice lab… or your boss looking over your shoulder while everyone is waiting for you to fix that nasty situation.
I had one of those errors in my last lab practice. Errors are both costly and eye opening, this one forced me to explore the IOS SIP debug commands. Of course, the downside was that I spent a good chunk of my practice time trying to fix a “simple” oversight.
Here is the scenario:
You have configured your SIP trunk according to specifications for outbound/inbound calling between enterprise and PSTN. However, all attempts to send a call through fail. Now you know its time to troubelshoot!
View original post 501 more words