This command is actually very overused. It was originally implemented as a workaround for a bug in early voice code. Since then, this command really shouldn't be doing much since the bug has been fixed since 12.2T code or so.
It made its way into some documents and now it's everywhere.
I've never solved a single problem with this command. I was able to make one thing come closer to working, but that ended up being a provider problem :)
This is an old thread, but I wanted to comment. Although it is over used, I solved a problem just in the last 6 months with this command. We had a situation with an h323 gateway using PRIs where all calls were completing normally accept calls to the 911 PSAP. 911 Calls where getting a one way audio situation where we could hear the PSAP but they could not hear us. Debuggin ISDN Q931 showed that we were never receiving the "connect" message from the far end, so audio was never getting cut through. We had to use the rtp send-recv command to cut through audio in order to get 911 calls working.
So my advice is not to use it unless you have to, but keep it in your back pocket.
I had to use this command on 2/2/2015 on a Cisco 2901 running IOS version 15.2(3)T2 in order to correct an issue with one-way audio on calls to 911. The gateway was configured as an H.323 gateway and was using ISDN PRI for connectivity to the PSTN. Before adding the "voice rtp send-recv" command on the gateway the site would dial 911 and could hear the 911 operator, but the 911 operator could not hear them. I added the "voice rtp send-recv" command which immediately corrected the issue, so it appears to still be relevant.
SIP traces provide key information in troubleshooting SIP Trunks, SIP
endpoints and other SIP related issues. Even though these traces are in
clear text, these texts can be gibberish unless you understand fully
what they mean. This document attempts to br...
Please find the attached HTML document, download and open it on your PC.
This provides an easy to use form where you simply answer a few
questions and it will render the proper jabber-config.xml file for you
to copy/paste. There is built in logic to verif...
CUCM Database Replication is an area in which Cisco customers and
partners have asked for more in-depth training in being able to properly
assess a replication problem and potentially resolve an issue without
involving TAC. This document discusses the bas...