Yep, Dex said it..., tell your customer to order caller ID (if they are copper lines) and you'll have it.
Different story if lines/trunks are on a T1
.. If it's a PRI your good!
Just dont go looking for a scrollable list of "previous calls" on any station. It doesn't exist.
If you need to keep any kind of list/log you'll have to use the SMDR port.
MrTelecom1
Re-Living the AT&T/Lucent/Avaya issues since 1979!