The number you dialed xxxx has not received a response from the service provider

[ATW136]

3 Obi110s
1 Netgear GS108T managed switch
1 ZyWALL USG 50
Callcentric on SP1

I prototyped the above configuration with 1 Obi110 and it was working.  After installing for production with 3 Obis, users are hearing the message I put in the above subject line.  I think the message is being issued by the Obi.

ZyWALL settings: ALG SIP enabled, Signaling Transformations enabled, Port 5060 default, added Port 5061 without success.

What is the Obi complaining about? And what do I do to fix it?

[QBZappy]

ZyWALL settings: ALG SIP enabled

Try disabling this. Many routers seem to work when this setting is disabled.

[ATW136]

Thanks QB. 

By trial and error I discovered that the "number ... provider" is an Obi message.  It was happening because the Obi was not registered with Callcentric.  Yet the call was placed and answered by the callee's answering machine and then the Obi message overrode.  I do not understand how the calling process could progress that close to completion with an unregistered Obi!

The answer was to reboot the gateway, then the switch, and finally the Obi.  I kept the SIP settings.  If I have more problems, I'll try changing those settings.