My thoughts, rants and musings on technology, life, or otherwise

I took a cursory glance at the newly release Android 2.3 SDK. There’s one item that immediately caught my attention, the addition of SIP.

My impression is that it is a very basic SIP stack. There’s not much to it. Create your session, tell it who you want to talk to (URI), make the audio call. What I don’t see (or it’s not readily apparent to me) is a way to easily extend the class to add to or modify the SDP. If I’m wrong, please correct me.

Doesn’t seem to support video. Doesn’t seem to allow use of different or custom media streams.

A particular project I’m currently working on involves the ITU’s V.150.1 specification and a VoIP product. It’s pretty neat. We’re taking something like modem data and using IP to transmit the data.

V.150.1 is one of those protocols that rides on top of UDP. It’s some times referred to as Modem Relay over IP or MoIP.  In this scenario it’s up to the end devices transmitting the data to maintain continuity and repetition.  V.150 creates the transport using State Signaling Events (SSE) and the SPRT transport layer.