[Users] thought exercise

I wonder if anyone on this list is open to a thought exercise? I'm trying to put together a cogent message about this, but in the meantime: I've got a situation where my openser box seems to route stuff to itself and it loops around and around until I get the classic "Too Many Hops" error. This seems to happen most often on BYE, although I've seen an ACK do it too. Here is a small ngrep snippet, after PHONE has called OPENSER-ONE who statelessly relays to OPENSER-TWO who t_relays to PSTNGW, and then the pstn user hangs-up: U 23:03:53.254382 PSTNGW:5060 -> OPENSER-TWO:5060 BYE sip:JoeUser@OPENSER-ONE.example.com:5060;user=phone SIP/2.0 Call-ID: callid@PHONE From: <sip:18005551212@OPENSER-TWO.example.com:5060>;tag=26674 To: "Joe User" <sip:JoeUser@OPENSER-ONE.example.com>;tag=thetag Content-Length: 0 CSeq: 1 BYE Via: SIP/2.0/UDP PSTNGW:5060;branch=thebranch Route: <sip:JoeUser@OPENSER-ONE:5060> Max-Forwards: 70 # U 23:03:53.255013 OPENSER-TWO:5060 -> OPENSER-ONE:5060 BYE sip:JoeUser@OPENSER-ONE:5060 SIP/2.0 Record-Route: <sip:JoeUser@OPENSER-TWO;lr=on;ftag=26674> Call-ID: callid@PHONE From: <sip:18005551212@OPENSER-TWO.example.com:5060>;tag=26674 To: "Joe User" <sip:JoeUser@OPENSER-ONE.example.com>;tag=thetag Content-Length: 0 CSeq: 1 BYE Via: SIP/2.0/UDP OPENSER-TWO;branch=otherbranch.0 Via: SIP/2.0/UDP PSTNGW:5060;branch=thebranch Max-Forwards: 69 Route: <sip:JoeUser@OPENSER-ONE.example.com:5060;user=phone> Right here OPENSER-ONE freaks out, and the delay causes OPENSER-TWO to re-transmit: # U 23:03:53.611227 OPENSER-TWO:5060 -> OPENSER-ONE:5060 BYE sip:JoeUser@OPENSER-ONE:5060 SIP/2.0 Record-Route: <sip:JoeUser@OPENSER-TWO;lr=on;ftag=26674> Call-ID: callid@PHONE From: <sip:18005551212@OPENSER-TWO.example.com:5060>;tag=26674 To: "Joe User" <sip:JoeUser@OPENSER-ONE.example.com>;tag=thetag Content-Length: 0 CSeq: 1 BYE Via: SIP/2.0/UDP OPENSER-TWO;branch=otherbranch.0 Via: SIP/2.0/UDP PSTNGW:5060;branch=thebranch Max-Forwards: 69 Route: <sip:JoeUser@OPENSER-ONE.example.com:5060;user=phone> OK, so who on this list is good enough to be able to suggest plausible theories about what my openser.cfg flaw is? If you don't want to speculate openly on the list then please send me a direct email. Thanks, -mark