Incoming calls drop on Aastra phones

I decided to setup freepbx after having used Elastix for a while and not using all the features of the system and not wanting to go through the hassle of upgrading from the ancient setup we had.
All has gone well except that our Aastra phones don’t stay connected to incoming calls, however outgoing calls have no problems. I have a couple of Snom phones that aren’t having any issues at all.
Any ideas as to what could be causing this behavior?

There were some updates that addressed a problem where the aastra phone would authenticate and then drop, but this wasn’t the whole problem.
If you set a number in the Caller ID field of the SIP Authentication settings it generates the following error:
chan_sip.c: Can’t find address for host ‘some phone number’

After this the connection drops. I’m not sure if this is an Aastra issue or asterisk but it makes me very weary of using Aastra for our phones in the future, plus the Snoms just look nicer even though they have an odd name.

I had a similar problem sometime back with this exact scenario on a WinMo 6.1 ip phone . I came to the conclusion the sipstack in WinMo was a little wonky in regards to doing nat traversal.
I changed in the extension settings the host= entry from default dynamic to static. After this I never had any more trouble with this phone and it still i s working without an hiccup.
May be worth a try changing this on one of your Aastra phones in the extension settings and try it.
Nothing very scientific on the troubleshooting. More than likely dumb luck that this worked.


Unfortunately this did not work. I think we still have some support with Aastra so I’ll give them a call and see what they have to say.