Incoming SIP calls to an N95 8GB are rejected if the caller's ID is withheld, if the incoming call has caller ID, the call is accepted OK. I've tried Voiptalk and Voipfone, and the same happens with both of them. If I use these SIP accounts with another SIP client, such as eyebeam, all incoming calls are accepted ok.

Voiptalk's support gave me the following information:

I compared the 2 SIP INVITES we sent with and without caller id and the only difference between the 2 was the 'FROM:' value set to anonymous when caller id was blocked.

This suggests the N95 is rejecting with the 'SIP 488' not acceptable message either because of the caller id that is not presented or because the FROM header was set to anonymous rather than left blank.

This was tested on an N95 8GB firmware v15.0.015. I don't have any other Nokia SIP devices to test this on.

Does anybody have an ideas why this is happening?

Thanks for any help.