[SIPForum-discussion] Does SIP support SSL, new protocols, early media, etc?

[Rodrigo Pimenta Carvalho]

Hi.

I'm starting with SIP and with a software project in my company. Today I have some beginner doubts:

1 - In my project a SIP client will call others SIP clients at same time, i.e., several SIP clients will receive SIP INVITE, like calling for a conference. But, when one callee answer the call, all the others must stop ringing immediate. The objective is let just one SIP client answer the call. it will be the first that will reply. Can the SIP protocol help me with this idea? Is SIP protocol prepared for such idea, in terms of its messages?

2 - In my project, a callee must receive and view the video from the caller, even before answering the call (early media). Can SIP help me with this requirement? How?

3 - I know that SIP can be used together SDP. And I guess that SIP can be used with any another protocol. So, let's suppose that I have created an new protocol based on Json. This protocol will carry information about some IP devices, like IP addresses and port. Can I send SIP messages with a new Json based protocol together? How can SIP help me with this idea?

4 - I need send/receive SIP messages encrypted, to provide secure to my SIP clients. In this case, what should I do to provide secure SIP messages using SSL or TLS? Does SIP protocol support this idea in some way? How?

Any hint will be very helpful!

Thanks a lot!

Best regards.


RODRIGO PIMENTA CARVALHO
Inatel Competence Center
Software
Ph: +55 35 3471 9200 RAMAL 979