My Linksys VOIP ATA was acting up, refusing to call one of my SIP services even though it claimed it was registered. I was on firmware 5.1.10 which has been the latest for a few years. Searching the internets for news of any update, I stumbled on the unfortunate tales of promises unfulfilled, as expressed in these threads:
and then ending up here
Basically, I’m facing the same problem as many. The ATA works fine until you make a call through your PSTN connection. This switches the SIP codec to G711u and locks it there. If you have a SIP service that demands something different (G711a in my case), you’re out of luck and the only option is to reboot the ATA. Any options you set are disregarded after the PSTN call.
I learnt from the discussions linked above that for three years, a group of dedicated owners have been chasing Cisco for a firmware fix. Support promised that the fix was in testing for years, continually pushing forward the release deadline. The last promise was US Summer 2011, and thats long gone now.
As someone who has worked for the last 22 years on many projects (including commercial simulation, realtime systems and satellite modems) with a release cycle measured in days or weeks, all I can say is that it was good to be made aware of this sorry 3 year saga before I upgraded the ATA with something new.
For now I’ve downgraded it to an earlier firmware version (5.1.7) which doesn’t have the annoying and stupid bug.