[OpenSIPS-Users] ACK never leaves opensips

[Stefano Pisani]

I have a strange issue with an ACK that never leaves Opensips. It 
disappears.
This is the ACK message incoming dumped with ngrep

U publicIP1:32769 -> publicIPOpenSIPS:5172
ACK sip:s at publicIP2:6050 SIP/2.0.
Via: SIP/2.0/UDP 192.168.4.53:32769;branch=z9hG4bK-nt6kbhw2yq7b;rport.
Route: 
<sip:publicIPOpenSIPS:5172;lr;ftag=dwlhrdursy;vsf=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA>.
From: "103" <sip:103 at publicIPOpenSIPS:5172>;tag=dwlhrdursy.
To: <sip:5002362 at publicIPOpenSIPS:5172;user=phone>;tag=as24f5fc71.
Call-ID: 313432313936303531313339303433-apx44rudybcq.
CSeq: 1 ACK.
Max-Forwards: 70.
User-Agent: snom710/8.7.5.13.
Contact: <sip:103 at 192.168.4.53:32769;line=a7hcmd7s>;reg-id=1.
Content-Length: 0.