SBC issues and SIP call flow through SBC

hello folks;

 

I am barand new to acme packet sbc. I need to understand how a sip call is processed through sbcany diagrams et please?

 

here is an issue that i am trying to resolve. We have a core sbc (acme packet 6000 series) being used for sip trunk service over mpls cloud. we manage mpls backbone and sbc and voice infrastructure.

 

the sbc's sip interface (on untrust realm side) is part of a subnet. This subnet is a /28 subnet. There is vrrp configured on the SBC side on Cisco network devices. The same /28 subnet is being used o allocate vrrp virtual gateway ip, as well as the sip interface ip on untrust relam of sbc.