Ring Group Problems

Hi I’ve had a recurring issues with ring groups that I’d like to share with the community and hopefully get some ideas. We’ve experienced this problem on several asterisk servers running the latest versions of 1.4 and 1.6 on several different hardware platforms.

In the CLI you’ll see that asterisk tries to call the extension and sends an invite, but never receives an ack. The extension is registered with the asterisk server at the time. The server is in a data center and all of the phones are behind NAT.

The issue is that sporadically (maybe one time in 10 or 20) a phone in a ring group won’t ring, even though all of the other phones in the same ring group or queue do ring. This has always been a lingering problem, but it happened so many times this week that I came in on a Sunday and made test call after test call until I was able to reproduce it and capture both the asterisk logs and a packet capture. Any help would be greatly appreciated.

I am sure anyone wanting to help would really appreciate seeing those logs as well…