I found out a solution with the Cisco Phones. There is an Option "Outbound Proxy" wich I didn't noticed before. It works if I set "Outbound Proxy" to SERs IP Adress and "SIP Proxy" to the Domain. But I have another problem with aliases. If I add some aliases (the same ones as in ser-0.8.14), they don't work. SER says "100@mydomain" not found in usrloc. Here is a short part of my ser.cfg: if (!lookup("aliases") && !lookup("location")) { sl_send_reply("404", "Not Found"); break; }; Jan Jankowski