[asterisk-users] Dropped call question - "Maximum retries exceeded on transmission"

[Dr. Michael J. Chudobiak]

Kohler, Jeffrey wrote:
> I am encountering an intermittent issue where some of my calls are being
> dropped.  Most of the calls that are made are successful.  However, some
> calls will be dropped after having been connected for some time.
> 
> Each time a call gets dropped, I get output similar to the following in
> the Asterisk console:
...
> Does anyone have any suggestions?  I honestly don't know where to start
> investigating this issue, so if anyone has any ideas they would be
> greatly appreciated.

Jeffrey,

That's all a bit vague (how long before it drops, what protocol, are 
there firewalls, etc...), but my first guess would be a firewall NAT 
timeout. See the "NAT Issues" section at 
http://www.voip-info.org/wiki-IAX for example (it discusses IAX rather 
than SIP, but you get an idea of the issues).

- Mike