Hi, I have a SIP trunk setup between C2801 cube and ITSP, ITSP gave us 4 IP addresses that will be involved in signalling and media source, so I configured the following ACL to limit outside access to my CUBE's IP 172.24.34.5
10 permit ip host 172.24.0.97 host 172.24.34.5 (50 matches) <== 172.24.0.97 is ITSP's softswtich
15 permit ip host 172.24.0.98 host 172.24.34.5 (3527 matches) <== 172.24.0.98 is ITSP's media source
20 permit ip host 172.24.0.113 host 172.24.34.5 (173 matches) <== 172.24.0.113 is ITSP's softswtich
30 permit ip host 172.24.0.114 host 172.24.34.5 (46604 matches) <== 172.24.34.5 is ITSP's media source
Once the above ACL is applied on ITSP's inbound interface, voice signalling is fine, but I always have one way audio -- audio from ITSP side can not be heard, ACL counters (for media) keeps incrementing normally during a call which means audio packets from ITSP are coming in. After I take off the above ACL from the physical interface facing ITSP's CPE, two-way audio resumes. SIP signaling debug confirms that there are only above ITSP's IP addresses are involved during a call.
What's up with this ACL?