How to use SIP GSM Gateway Server in C# (asp.net) application?

Question

Telephony

you need to create a service for calls through the site.
I understand that the Architecture is as follows:
SIP Server (a program that works with modems) creates a TCP-based interface through which
our .net application will interact. There it seems to be necessary to use C# libraries that are
necessary to simplify the work with the SIP server.
Share the names of programs / libraries, maybe something else is better to use, unlike SIP GSM.
Can you tell me where is the source of such projects.

Answer 1

In general, I do not know what others use in web applications, but in such tasks I use the RTP protocol.
RTP