[SR-Users] Subscribers and peers handling

Hello, We are trying to build a lightweight SBC solution for some external peers, but currently there is a mixed environment which is handled by Asterisk. We have some "peers" with IP based auth, and also some "subscribers" with register. We have succeded with the subscribers, because we can handle the numbers for those type of users with aliases in Kamailio. So basically we have a subscriber, lets call it "test", and we can add aliases for the subscriber like "3612345678@localhost", then if we are calling the number the routing goes to the contact of "test" subscriber. Currently the problem is that we dont have any idea about the IP based peers, because those peers not registering, so we cannot create aliases for them as far as i know. How do you solve this type of problem? Maybe im overcomplicating the situation, but i havent got any solutions in my mind currently. Thanks for your help and ideas. With kind regards, Zoltan