Zu56, there is no CDR link "inside the switch" it communicates (in general) over the CLAN card, to the Call Accounting system, via an IP connection... unless you have it setup old school, to use the RS232 serial port, if you have an older SI switch... even then, the CDR/RTS lines must be correct for the data to go out the serial port.
Sounds like you have an IP connection setup, so without your call accounting system running, the CDR link will be down...
mitch
AVAYA Certified Specialist