Some users will be seeing problems with their SIP phones/devices not registering against registrar.aasip.co.uk - we are investigating this at the moment.
We may have tracked this down - phones should be able to register ok now and we're monitoring the situation.
VoIP does appear to be stable again now.
The service was stable over night, and has been fine today.
This problem just returned. Back now.
We're getting closer to finding the cause.
Service stable again now.