Implementing SIP for WebRTC on iOS

Question

I am building an RTC iOS app client. I am using the google WebRTC iOS library. However, since WebRTC doesn't implement signalling I am searching for an easy way to implement a SIP stack at the signalling layer. I tried Pjsip but it didn't work:

• First, I followed this Pjsip guide Integrating Third Party Media Stack into PJSUA-LIB but I didn't know how to proceed, especially that both projects have a big overlap (both implements NAT traversal and SDP). Also, the Pjsip is in C, WebRTC is in Obj-c and the whole app will be in Swift.
• Second, I created two separate projects, one for Pjsip and one for WebRTC and both ran successfully on iOS. Then I tried to combine the two projects in one as a first step, but it turned out that both projects use libsrtp but different versions of it, the thing which caused conflicts and compiling errors.

I am not sure if Pjsip is really what I need, especially that WebRTC already has all the features I need except for SIP signalling. I would be thankful if anyone can guide me to how to proceed with Pjsip or give me another open-source easy to use SIP library.

Thanks.

Answer 1

You may want to use (and potentially contribute to) RestComm iOS SDK at https://github.com/Mobicents/restcomm-ios-sdk. It uses Sofia SIP Stack.

Answer 2

I found a nice open source SIP library with small footprint called libre.