A service provider in France (Neuf Telecom)is proposing a converged Mobile/IP offering (called Twin) on a dual mode phone (called Twin Tact - a china manifactured phone with Neuf firmware on it).
This offering is based on a SIP proxy (not UMA).
In a SOHO environment with multiple access-points (AP521) with overlapping coverage & on the same subnet and without any security configured during the tests, roaming bewteen APs works without breaking the connection, but introduces a 3 to 5 seconds loss of voice - communication becomes blank until it resumes fine from the new access point. The SIP session isn't lost, but it looks like RTP packets are lost for 3-5 seconds, and it looks like this phone waits until it completely looses the signal to start the association process with the new AP.
Does anybody know how to reduce the 'blank' time or change the phone's behavior ? Even without the fast secure roaming functionality or a WCS, that time doesn't sound right...
Thanks a lot,