Ever had a DSX80 crash the network?

trying to figure out why the network was down in a remote office...

Tried pinging, power cycling all network devices, called isp, they got into their devices and could see our devices, rebooted their device....

Was thinking it was a 24 port switch which would explain everything but right before I got to my local office to pick up a spare switch and head that way, the remote office calls and says they unplugged and plugged back in the big black box on the wall (aka dsx80) and the network came back up...

it is connected to the network so I can make changes remotely...but, other than another device on the network with the same ip, how on earth could the dsx80 pull down the network?