We are investigating the Janus SIP plugin and are curious if it is possible a VideoRoom audio publisher to be published to the SIP server by joining the SIP server as a subscriber to the VideoRoom. Is that possible? Or the client needs to publish his audio twice - once to the VideoRoom and once to the SIP server, so SIP phone users hear him?
Is the idea of the SIP plugin that from the browser user directly opens a PeerConnection to the SIP server and SIP plugin is just the SDP mediator?
We are trying to see what to do for web browser users who already publish their audio to the VideoRoom and that audio needs to be heard by SIP phone users too. We would like to avoid the double publishing of audio from the browser - once to VideoRoom and once to SIP server.
I suppose it should be possible to pass a VideoRoom subscription SDP offer as a “call” request to the SIP Plugin? And then pass SIP Server’s answer to the “start” subscription VideoRoom request. That would make Janus establish a peer connection to the SIP Server and send the audio of the existing VideoRoom publishers?
The plugins are so different that it makes little sense to bridge them: the VideoRoom uses monodirectional m-lines, the SIP plugin is bidirectional; besides, the SIP plugin doesn’t support multiple streams (and neither do most SIP servers). For some customers in the past we created helper applications that can act as audio mixers for SIP while keeping audio relayed for VideoRoom users, but that would indeed require a separate application. See for instance slides 33-36 in this old presentation: Can SFUs and MCUs be friends @ IIT-RTC 2020 | PPT