SIP on N9 unregistering after 10 mins
 

This is a question for all you SIP experts on the N9.

Basically the device unregisters a little while after registering. This means that although I can still make outgoing SIP calls I can no longer receive SIP calls. It will register again if I make a SIP phone call, but then will unregister a short time later again. Basically this is as good as being useless, if I can't receive calls most of the time.

Does anyone know the solution to this? Maybe some sort of keep-alive script? I have tried changing the keep-alive settings, but it hasn't made a difference.

Re: SIP on N9 unregistering after 10 mins
 

Are you sure it's N9 problem and not your firewall problem?
I had a similar issue at home with my VoIP phone, but it was due to the fact that my stateful firewall was leaving open the STP/RTP ports only if I was calling.

Solution was to add port forwarding for STP/RTP service to the IP address of the VoIP phone device.

Re: SIP on N9 unregistering after 10 mins
 

Is this problem over wifi or 3G? or both? If this happens on your personal wifi network, check whether SIP ALG is enabled on your router. If it is, disable it - it usually creates more problems.

Your phone is likely NAT'ed and the SIP proxy will want to keep the NAT open by sending a keep-alive; and your SIP UA will also be prompted to reregister periodically. When you say you tried changing the keep-alive settings, what exactly did you do? and which keep-alive mechanism are you using? (OPTIONS ping is usually a safe bet.)

Re: SIP on N9 unregistering after 10 mins
 

Well it happens on the 3G connection as well, although the problem seems worse on the home router where indeed it is NATed.

I notice that the connection status in the status menu doesn't show a green circle like it does with google talk and skype connections, but a light brown or orange circle with clock hands inside. Could this have anything to do with it?

Re: SIP on N9 unregistering after 10 mins
 

PS. I had tried changing the keep-alive period (which can be between 1 minute and 1 hour) as it was not clear to me if this is the period during which the connection is kept alive, or the period of how often a keep-alive is sent, so I wanted to try both extremes (to no avail). The mechanism I had always kept as automatic, now I will try OPTIONS though.

Is there any reason to try a different voip provider, maybe one which tries to server mobile clients more actively?