I have been reading about SIP and SIP Servers, especially Asterisk.
Something is still confusing me: What happens if the IP address of the peer (recipient) changes?
How does Asterisk know that the IP has changed? Or does the peer have to send a signal to Asterisk that it has changed its IP? and how does it update it on the server?
I realize this sounds like an open question, but I could not find the answer anywhere on the web. Can someone point me in the right direction for an explanation of how this situation is handled?
Peer is responsibel for sent REGISTER message with auth info
Once that message come, asterisk depend of settings set ip to ip in message OR ip from which message received.
If ip changes and no new registration message recived, it will just nto work until new registration. So for 4g or other "bad" links you have set re-register interval to low values like 60 second