Can someone tell me what is going on here? 2nd time this client has experienced this. It's an older bunch of folks using this phone so not sure if they're doing it, or what? SP3 is calling SP2 and tying up the line nonstop.
We've had this sort of issue before and as @SteveITS mentioned, it was a PBCAK. To kill the SP1 to SP2 call, they can just press one of the BLFs and hang up. It'll kill both calls.