Snom phone issue with STUN

During the past two weeks I discovered, rather painfully, that if the DNS provisioned on a Snom phone (360 with the 7.3.7 firmware) cannot resolve the IP from the FQDN of a STUN server, the phone is converted to an light paperweight.

Every one of the identities which have this STUN server provisioned, fail to register completely. There is no indication of this failure on the display of the phone, except the [x]s on the left of every affected identity.

The web interface of the phone remains accessible, but there is no indication of the failure there either. The SIP Trace remains empty, as if the SIP stack on the phone is shut down. This is a pretty serious issue, since there is only one location to specify a STUN server entry per identity.

I uncovered this issue after my 360 failed to resolve the IP for stun.fwdnet.net so if you use this STUN server, consider changing it. I have reported this failure to Snom and they are currently looking into it.