We've had this setup working for years with an NSA 240 at the main location and a TZ100W at the remote location. Phone worked great without any issues. Now we're running into an issue where the phone at the remote location can no longer hear audio from the caller. I swapped out the NSA240 for a TZ500 last night, but same issue remains. Site to site VPN is up, and file access works, but the phone is still only getting the one way audio.