Edit: Should probably mention this is a 9.5 mile link with antennas ~120' in the air across flat terrain so the fresnel zone is quite clear. There's no geographical issue precluding communication between the two sites.
Mikrotik wireless configuration is basically default settings with exception of configured SSID and encryption, and set to use the channel the old hardware was transmitting on. Nstreme is enabled. When the radios were first installed, they linked up immediately. Same RSSI as old hardware, as expected (low -60s dBm) and no interference whatsoever (-105ish dBm noise floor). CCQ was great, 100%+ both directions and I was able to pass 36mbit over the link with the bandwidth test with no issues whatsoever for ~5 minutes. There was no variation in CCQ or actual throughput at this point.
Within a day, though, the link degraded. The client started dropping off for minutes at a time with logs stating that the loss was due to extensive data loss. The client was also seeing a rx rssi different than the tx rssi -- -85ish as opposed to the -62 it was transmitting at. CCQ also drops to ~40-60% in both directions at this point. After a while, the link would come back up, the rx rssi would go back up and traffic would pass properly again.
Testing at the client end shows that the issues are as expected due to downstream traffic. I can run an upload bandwidth from the test, which maxes out at ~5-6 mbit, abd after a few minutes the link will drop. A download bandwidth test kills the link immediately.
- We've tried:
- Looking for other people transmitting via the freq usage feature. Noise floor is extremely low (-105 dBm+ across all frequencies) and no transmissions on any frequencies are seen.
- Different frequencies; no effect whatsoever.
- Dropping the channel width down; raised RSSI slightly keeping it from dropping offline continually.
- Limiting it to 802.11a-only modulations; seemed slightly better performance but still drops for a few minutes approx every hour.
- Disabled Nstreme; connection performance got worse and the link could barely be sustained.