How to implement ip-telephony?

Question

Java

it is necessary to implement sip-telephony using java (multichannel, hold).
tell me how to do it?
you need to connect to the sipnet.net acc.
jitsi, jsip - have not yet succumbed.

Answer 1

sipnet seems to have no webrtc, we raised our server with freeswitch, everything is fine there, you can use it as a proxy to sipnet

Answer 2

www.mizu-voip.com/Software/WebPhone.aspx