Hi all, My topology is as follows: Kamailio  -> FS (SBS+Media server) I came across an issue with my system as follows.  I have a Hardphone registered. When I do local call inside kamailio, it gets to FS and returns back well and FS understands when I lift the handset. However, I added a gateway (german landline server), when I call my self from another phone, the call gets to FS and then transmits to Kamailio, it rings my extension but when I lift the handset FS does not notice it and keeps ringing. Any body has an Idea? Here is my gateway trunk. <include>         <gateway name="trunk_1000">         <param name="realm" value="bluesip.net"/>         <param name="username" value="bluesip/xxxxxx"/>         <param name="register" value="true"/>         <param name="extension" value="kb-1002"/>       </gateway> </include> thanks in advance Sherif Omran