4f55f5cb_ISDN_Cause_Codes__Cause_Usage
[Cause#] 127 [Fixit!] N/A [Cause Summary] Interworking, unspecified. [Cause Usage] 
Indicates there has been interworking with a network that does not provide causes for actions it takes; thus, the precise cause for a message being sent cannot be ascertained.
ISDN Cause Codes
Cause Usage