VoIP Phones that run through Site to Site VPN keep going down.

Hi everyone,

I am trying to track down the issue with our Panasonic phone system. We have a remote branch that uses a Site to Site VPN to another location and gets its IP info from that branch for the VoIP phones.

Occasionally the remote branch IP Phones will complain about Poor LAN connection (can't talk back to the main pbx)

I'm doing a trace route from the ASA (one is a 5516x and one is a 5505) from the remote location using the source IP as the internal firewall address and on the port that the phone system wants to the internal IP of the other location's firewall internal IP.

When doing this, I get a

(acl-drop) Flow is denied by configured rule)

With that- it seems like it shouldn't work at all rather than break occasionally.

Where am I goofing up? I am pretty early with ASA knowledge and the phone system is a whole beast of its own. Any help would be great.

Thanks.