We upgraded our, 4600c eptp links to 5.9 the other day. After the upgrade, we started to have OpenR errors in our cnWave network and retransmits on another link used to connect a couple of tower sites. After spending a lot of time scratching our head and chasing ghosts on the network, we discovered that after the upgrade of the 4600c the MTU gets set to default at 1538 instead of the 2000 it was set to before the upgrade and the power levels that were manually set got reduced drastically reducing the RSSI and increasing retransmit. After re-setting the configuration to the way it was before the upgrade, everything is well.
Hopefully this saves someone some time after their upgrade!
I feel your pain GREG3F - we have also had this issue with Force425 with MTU. We had customers everywhere ringing with strange issues after upgrade ( I think it was to 4.7 or 4.7.1) and finally tracked it to this. I opened a case with Cambium Support and it is still open nearly 9 months later. We just know now that on upgrade we need to go through everything and check that nothing is reset to a default value including MTu and Power Levels. Cambium Support if you are readeing please ensure all fields remain the same after upgrades.
The issue has been confirmed. It’s a side effect of implementing MTU 9600 for TDD mode.
MTU for ePTP, WLR and TDD modes are controlled by the single parameter in 5.9, while there were different parameters used for different Driver modes in 5.7.2.
I apologise for the inconveniences caused.
I’m putting this data on 5.9 Release Notes.