4f55f5cb_ISDN_Cause_Codes__Cause_Usage
[Cause#] 82 [Fixit!] N/A [Cause Summary] Identified channel does not exist. [Cause Usage] 
Indicates that the equipment sending this cause has received a request to use a channel not activated on the interface for a call. For example, if a user has subscribed to those channelson a primary rate interface numbered from 1 to 12 and the user equipment or the network attempts to use channels 13 through 23, this cause is generated.
ISDN Cause Codes
Cause Usage