About SIP, VOIP, Windows CE .NET and Microsoft Smartphone
Smartphone 2002 does not support SIP or VOIP. You cannot upgrade your
Smartphone to .NET 4.2, you need to wait until a future release of
Smartphone comes out that is based on 4.2.
Note that a future release of Smartphone 4.2 is not guaranteed to have SIP
or VOIP support either, just because it runs on 4.2. Windows CE is modular
and many items that are available in Windows CE are not available in
Smartphone.
