I'll change some more values, save and reboot. The ping tests were done with using the Asterisk command line.

We did a reboot of the remote end that our router is connected to at the site, and it came good for a little while. Pings are good, but they drop on average 4 in every 100 or so... But no great spikes indicating congestion. All this is over the internet by the way.

My Pi is running at 100MBps into the router, and the RTCM is 10Mbps half duplex.