I set up a couple Ubiquiti NanoBeam AC (NBE-5AC-16) access points in a bridge about 400 meters apart. I updated the firmware, disconnected the old site to site VPN, connected the bridge and traffic started flowing. I then went in to the alignment tool and it looked so good I decided I didn't need to go back on the rooftop and align them. I then ran a speed test with a channel width of 80 Mhz and reached the theoretical maximum so I figured I was good.
As I tested the connection by running pings across, I noticed that they were inconsistent. Many were 1ms, but others were 3ms or much higher. I figured it would be better than the old internet based site to site VPN, so I left it in production. Later that morning, users were calling and I had to drop back to the VPN. When they called me on their VoIP phones, I noticed static on the call.
I did some reading and it looks like I might have to drop the channel width down. I tried dropping it remotely and running a speed test, and it took the speed from 451Mbps to 145Mbps, which is still acceptable as long as the connection is more stable. Is that the right thing to do, or should I be looking at other things? I should add the main reason I wanted to put in the wireless bridge is that the site to site VPN connection isn't stable enough for their terminal server sessions.