I have a customer that has an OS-7200S in Virginia with approx. 35 VOIP local VOIP phones, SMT-i6021, 6011 & 3105's. Customer has Clearfly SIP trunks. No issues locally.

For months, we have been fighting random no audio issues for approx. (12) VOIP phones connected via a VPN to Atlanta Georgia. It does not matter whether it is an intercom call from Georgia to Virginia or a SIP trunk call that has been transferred to Georgia random no audio calls happen often.Even when one Atlanta phone calls another Atlanta phone, no audio often happens.

Fortigate firewalls on each end. All of the proper stuff has been turned off - SIP helper/ALG, etc. IP scheme 10.10.11. xxx in VA. 10.10.12.xxx in Atlanta

Virginia site has Cox Communications as the ISP. Atlanta Georgia - Comcast is the ISP.

As a test we set up a remote phone in our office coming in on the public side with port forwarding. Our office is in the same city as the OS7200-S and we are on Comcast. On remote extension 2314 with a mailbox as a test, we press ## for voicemail quick memo. We can do this 30 times and 4-10 times, we hear no audio and no message can be recorded.

A support company we are working with in Florida set up the same extension as a test and got the same no audio issue - they are on Time Warner.

The strange thing is that when we look at a failed call packet capture, the packet capture has audio that we can play back and hear the audio stream. You press ## and the Samsung system says "Quick Memo"

I TOOK AN SMT-i6011 home with me this weekend and did the same ## test. My residence is using Cox Internet. My customer is using Cox internet.

Using Cox to Cox, I MADE HUNDREDS OF ## TEST CALLS INTO THE SYSTEM AND LEFT HUNDREDS OF MESSAGES WITH NO FAILURES.

Have you ever seen this before? It has baffled us.

MikeS In VA