We are often asked this question about audio codec or video calls. Some customers want to confirm whether miniSIPServer can work well with their SIP phones/clients who can support several audio codecs or video calls.
We often answer that it depends on their own SIP phones/clients. miniSIPServer, not matter local-miniSIPServer or cloud-miniSIPServer, doesn’t care media codec by default.
Why we say that?
Please have a look at following figure which describes a basic media process model of miniSIPServer in a normal basic call.
From this figure, we can see:
(1) miniSIPServer only controls call signals.
(2) Media stream is processed by the clients themselves.
This model will reduce the work-load of the server since all media streams are bypass server, so it is unnecessary for the server to support several media codecs.
But in some service scenarios, miniSIPServer need play audio to the SIP phones. For example, in auto-attendant or calling card services, miniSIPServer need prompt audio announcement and collect user input information. Obviously, miniSIPServer is required to support audio codecs in these scenarios.
That’s right. If miniSIPServer need process audio stream, it can support two audio codecs: G711a (PCMA) and G711u (PCMU).
By the way, after playing audio stream, the final media stream will be processed still in end-to-end model. Please refer to following media model of miniSIPServer for these scenarios: