Hi all and thanks for reading. Here is the scenario: SIP Phone > PBX > Proxy > SBC (acting as B2BUA)
The INVITE reaches the SBC and it responds with a 183 Session Progress then 200 OK. The call is dropped after 15 seconds because the SBC never receives an ACK to the 200 OK. The 200 OK from the SBC is formatted as such: SIP/2.0 200 OK Via SIP/2.0/UDP <PROXY IP> Via: SIP/2.0/TLS <PBX IP> Via: SIP/2.0/TLS <Phone IP> From: "SIP Phone" IP To: <sip:destination@SBC IP> Call-ID Cseq: 1 INVITE Record-Route <sip:111151bc@PROXY IP:5060;transport=udp;lr> Record-Route: <sip:PBX IP:5061;transport=tls;lr> Accept: application/sdp, application/isup, application/dtmf, application/dtmf-relay, multipart/mixed Contact: <sip:number@SBC IP:5060> Allow: INVITE,ACK,CANCEL,BYE,REGISTER,REFER,INFO,SUBSCRIBE,NOTIFY,PRACK,UPDATE,OPTIONS P-Charging-Vector: icid-value="value here" Require: timer Supported: timer,replaces Session-Expires: 1200;refresher=uac Content-Length: 279 Content-Disposition: session; handling=required Content-Type: application/sdp <SDP INFO> Based on that 200 OK, should the PBX respond with an ACK directly back to the proxy, or to the SBC? I'm not clear on how the flow should work in this instance. At first I thought the SBC should have inserted into the Record-Route, but apparently that's not the case for B2BUAs? Thanks! _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
