Hello there, According to , https://lists.kamailio.org/pipermail/sr-users/2016-March/092058.html, which talked about B2BUA (just signalling) in Kamailio. As i have experienced working with SEMS, freeswitch and Kamailio while using B2BUA feature, Each of them have pros and cons: 1- The sems is a light sip engine server with several applications (like as sbc) for using b2bua. All incoming and outgoing calls could go to sems server for doing b2bua like this:
Incoming<=======>Kamailio<========>Sems<========>Kamailio<=======>outgoing
2- In sems, you could disable rtp realying. It forces sems to work just as b2bua without anchoring RTP 3- Easy to use different active profiles in routing. Just a couple of things there are in SEMS. For example, the sems adds itself (local IP) in Via header, and it couldn't be common in b2bua. like this: . . . INVITE sip:200@cloud.domain.com;transport=UDP SIP/2.0 Via: SIP/2.0/UDP 10.10.10.200;branch=z9hG4bK2f53.07a3fd9edaa8c8d609ab2ac6b01a087f.0 *================================>Kamailio public IP* *Via: SIP/2.0/UDP 127.0.0.1:5080;received=127.0.0.1;branch=z9hG4bKsPRMNast;rport=5080 ===============================>private loopback sems ip* From: sip:100@cloud.domain.com ;transport=UDP;tag=6FFDB493-60EABB3600016ECD-379F9700 To: sip:200@cloud.domain.com;transport=UDP CSeq: 10 INVITE Call-ID: Y2M1ODQxNTZmMjdkZWZjN2U5MmMyYjBmN2Y2OGY1ODQ._leg2 Route: sip:mo@127.0.0.1:5060;lr Max-Forwards: 69 Allow: INVITE, ACK, CANCEL, BYE, NOTIFY, REFER, MESSAGE, OPTIONS, INFO, SUBSCRIBE User-Agent: Z 3.3.25608 r25552 Content-Type: application/sdp Contact: sip:127.0.0.1:5080;transport=udp Content-Length: 246 . . . For this reason, Is there a way to avoid this issue? I know it is possible to do this by using other modules like textops and retransformation ? And why in Kamailio, there is no b2bua module to perform all b2bua functionality, yet? Thanks with Best Regards.