Hello All, We have Installed Kamailio in Debain 8. All p,s,i and hss servers are in one PC. We are able to register the users(Alice and Bob). When initiate call from Alice , INVITE is passing through Alice -> p-cscf -> i-cscs -> s-cscf -> i-cscf -> s-cscf when it is reaching again s-cscf server, we are getting error .(403 Forbidden - Domain not served) We are attaching all logs and wireshark logs. Kindly let us know, where and why it is failing. regards, Prasannakumar. On Thu, May 25, 2017 at 4:18 PM, Prasannakumar Merugu < mprasanna469(a)gmail.com&gt; wrote: