Well, after trying numerous QoS settings in my RV082, and even replacing my RV082 with a Netgear managed switch with advanced QoS settings, I have been unable to get reliable faxing using Vonage over Comcast. In fact, it has gotten worse, I could no longer even send a Vonage to Vonage fax or a fax between Vonage and RingCentral in either direction.
Since Vonage had recently sent me notification that the price was going up on the line that I had been using for faxes, I took that as an omen and canceled that line, killed my Windows fax service, and disconnected the USR fax modem. The RingCentral fax service works with no problems.
Of course, even though I hated having to change from a local fax service to a hosted fax service, the RingCentral service is less expensive than a Vonage line, and the troubleshooting process left me with a cleaner/simpler network infrastructure. I could actually remove the Netgear FS105 now that I only have one Vonage router, but I have left it in place because I will probably be installing a 3G MicroCell soon, and that is where it will connect.
We can never have enough of nature.
We need to witness our own limits transgressed, and some life pasturing freely where we never wander.