So we were running into an issue with our UC520 where calls would not hang-up properly (green light on the UC would stay on even if we physically disconnected the cable, on a PSTN line).
After talking to a guy at Cisco, he told me to check with our phone provider which type of disconnect signaling they were using.
Our provider uses Loop Start by default, but they can change to Ground Start if requested.
I've found some documentation on Cisco about Ground Start, but don't know which one is "better" (if even it botters to have a "better" disconnecting method ?).
Should I use Loop start, or ask them to switch to Ground Start.
In either case, can someone point me to some kind of documentation on how to configure them properly.