How can a system (Asterisk) accept realms? I mean, for example we have two SIP accounts: exampleuser@test.com and exampleuser@anothertest.com. For Asterisk by default, these two accounts are the same since the user is exampleuser for the system. I want the domain to be also included in the username, so for example to accept only users with a certain domain.
How can this be achieved? Guides or books referring to this topic are well accepted :) .