The call does not complete between and avaya aura and a sip server over a big ip-ltm
ISSUE There exist a problem in the establishment of a sip call. We are communicating an avaya aura sbc over a virtual BIG IP-LTM with a sip server using the port 5060. The sip invite pass correctly from the avaya sbc through the f5 and gets to sip server, but inside the sip invite message came a parameter in the Record-Route tag which indicates another port (5066), when the sip server answers back with the SIP 200 OK the traffic isn't processed by the Virtual server and never came back to sbc.
The Near-end Listen Port and Far-end Listen Port may have been modified within your Aura Signaling Group configuration. Here is an Avaya white paper where TELUS is the SIP service provider; buried down in the paper is a section that discusses Signaling group configuration. Avaya White Paper
Try creating another virtual server (same address as your 5060 VS) and pool using port 5066 on the BIG-IP to see if your issue is resolved. You will most likely need to set your persistence to use "Match across services" to maintain client persistence to the same pool member.