I've been trying to get the ChipFlip SIP sample application to work on Nokia 7610 target devices, without success. The devices register correctly to Iptel.org's SIP server and the invites occur correctly, but when the devices should open direct socket connections between them, nothing happens, as if the connection request dies somewhere in the GPRS gateway on either side.

The questions I'd like to have answers to are the following:
- What kind of mobile operator and service dependencies exist? In which mobile network has the application been tested? I've been using Sonera's network in Finland.
- Do any additional target device requirements exist? I've been using the 7610 devices with the SIP Plug-in 2.0 in S60 v2.1 SDK.

I sincerely hope that Forum Nokia's staff would notion this message and dig the information from the application developers.

Tero Hakkarainen
VTT Information Technology