I haven’t touched a BlackBox box in quite some years, but if memory serves, there’s not much good to say about them.
I’m sorry that I don’t have much to offer other than my advice to stop bridging a network that size across phone lines.
If you’re stuck with this design because your boss implemented it and you can’t afford to make him/her look bad, then you have my sympathy, but certainly not my envy.
If you go to routers, your performance overall should pick up significantly.
If it’s a political difficulty, perhaps (I don’t know your employer’s history) you could bring up the point that the network has grown beyond the ability of a bridged network.
Even Microsoft finally dropped their bridged network 5-10 years ago.
Please go to routing! Please go to routing!
This is a recording!