I'd like to help get best performance from your PtP bridge link. It is very important
that you set the Distance parameter on both RB and NRB to match, and close to
the relative distance between your 7731s.
At just 270 meters, you would use the minimum 1KM setting.
From Configuration::Wireless, clice Advanced Settings button. Use the other
default values, but change the Distance field to be 1 KM.
With this configured on both sides, the next advice is to run Channel Optimizer
from your Root Bridge, under Status::Wireless, click the Start Channel Optimizer
Process link. Your RB will flood the link with UDP in both directions to determine
the best overall throughput channel to use.
When the RB finishes, it will be set to the best channel (according to current RF
conditions). Evaluate the performance on this channel. If you need further
troubleshooting, collect your Support Info, from Maintenance::Support Info page,
from both side bridges, and open a case with Tech Support for deeper RF
analysis.