User manual
Appendix A-Disconnection Causes
A-16
97 Message Type 
Non-Existent or 
Not 
Implemented
A message was received that is of a type that is 
not defined or of a type that is defined but not 
implemented.
98 Message is Not 
Compatible with 
the Call State, or 
the Message 
Type is Non-
Existent or Not 
Implemented
An unexpected message or unrecognized 
message incompatible with the call state has 
been received
99 An Information 
Element or 
Parameter Does 
Not Exist or is 
Not 
Implemented
A message was received containing elements 
or parameters that are not defined or of a type 
that is defined but not implemented.
100 Invalid 
Information 
Element 
Contents
A message other than SETUP, DISCONNECT, 
RELEASE, or RELEASE COMPLETE has been 
received which has one or more mandatory 
information elements containing invalid content.
101 The Message is 
Not Compatible 
with the Call 
State
A STATUS message indicating any call state 
except the Null state has been received while in 
the Null state.
102 Recovery on 
Timer Expired
An error handling procedure timer has expired.
103 Parameter Non-
Existent or Not 
Implemented – 
Passed On 
(national use)
A message was received containing parameters 
that are not defined or of a type that is defined 
but not implemented.
Table A-2  ISDN Disconnection Causes (Continued)
Disconnection Cause
Number Summary Description










