Appendix I
Definition of causes values

(This Appendix does not form an integral part of this Recommendation)

Recommendation Q.931 (03/93)

Table I.2 indicates the usage of cause values within this Recommendation. Other usage may be provided within other Recommendations, e.g. Q.700-Series and Q.699. Other causes may also be used by Q.931 entities where this is not precluded by the procedures defined elsewhere in this Recommendation.

Table I.1 defines the key for the location of generation in Table I.2. For more precise usage of the location codes in the cause information element, see Recommendation Q.850.

Table I.1/Q.931

Key to the location in Table I.2

LU	Local user
LN	Local network
TN	Transit network
RN	Remote network
RU	Remote user
LPE	Local peer entity (for symmetrical operation, see Annex D)
The following abbreviations to message types are used in Table I.2
CON CON	CONGESTION CONTROL
DISC	DISCONNECT
REL	RELEASE
REL COM	RELEASE COMPLETE
RES REJ	RESUME REJECT
STAT	STATUS
SUSP REJ	SUSPEND REJECT

Table I.2/Q.931

Usage of cause values

						Typical location	Typical carrying message as identified by receiving side
Cause No.	Class	Value	Cause name	Diagnostics	Reference	of generation	At remote interface	At local interface
11	000	0001	Unassigned (unallocated) number	Condition	5.1.4	LN		REL COM DISC
					5.2.4	RU	REL COM DISC
12	000	0010	No route to specified transit network	Transit network identity/network specific facilities info. elements	C.2	TN		DISC
					E.3	LN		REL COM
13	000	0011	No route to destination	Condition	5.1.4	LN		DISC REL COM
					5.2.4	RU	REL COM DISC	DISC
16	000	0110	Channel unacceptable	-	5.2.3.1 c) 5.3.2 d) 6.2.2.3.1	LN		REL
17	000	0111	Call awarded and being delivered in an established channel	-	6.2.2.3.1	LN		REL
16	001	0000	Normal call clearing	Condition		RU	DISC	DISC
17	001	0001	User busy	-	5.2.5.1 5.2.5.4 b)	RU	REL COM	DISC
					No procedure	RN		DISC
18	001	0010	No user responding	-	5.2.5.3	RN		DISC
19	001	0011	User alerting, no answer	-	5.2.5.3	RN		DISC
21	001	0101	Call rejected	Condition: user supplied diagnostic	5.2.5.1 5.2.5.4 b)	RU	REL COM	DISC
22	001	0110	Number changed	New destination number	5.1.4	LN		DISC REL COM
					5.2.4	RU	REL COM DISC	DISC
26	001	1010	Non-selected user clearing	-	5.3.2 b) 6.2.2.3.1	LN		REL
27	001	1011	Destination out of order	-	5.8.9	RN		DISC
28	001	1100	Invalid number format (incomplete number)	-		LN		DISC REL COM
					5.2.4	RU	DISC REL COM	DISC
					5.1.5.2	LN		DISC
					5.2.4	RN		DISC
					5.1.4	LN		DISC REL COM
29	011	1101	Facility rejected	Facility identification	No procedure in Q.931	LN		REL COM DISC
						RN		DISC
						RU	REL COM DISC
30	001	1110	Response to STATUS ENQUIRY	-	5.8.10	LU, LN		STAT
31	001	1111	Normal, unspecified	-	5.8.4	RN		REL COM DISC
34	010	0010	No circuit/channel available	-	5.1.1 5.1.2 5.1.5.1 5.1.5.2	LN		REL COM
					5.2.3.1 b) 5.2.3.1 e) 5.2.3.2 6.2.2.3.1	RU	REL COM	DISC
					C.2	LN	REL COM DISC	REL COM DISC
					C.2	TN		DISC
					D.1.1 e) D.3 b)	LPE		REL COM
38	010	0110	Network out of order	-	No procedure
41	010	1001	Temporary failure	-	5.8.8	LU, LN		DISC
					5.8.10	LN, RU, RN	DISC	DISC
42	010	1010	Switching equipment congestion	-	No procedure			REL REL COM
43	010	1011	Access information discarded	Discarded into element identifier(s)	7.1.5.7	RU, LN, RU		CON CON
					5.8.7.2	LN, LU		STAT
44	010	1100	Requested circuit/channel not available	-	5.1.2 5.1.5.1 5.1.5.2	LN		REL COM
					5.2.3.1 e) 5.2.3.2 6.2.2.3.1	RU	REL COM	DISC
					D.1.1 e)			REL COM
47	010	1111	Resource unavailable, unspecified	-	No procedure
57	011	1001	Bearer capability not authorized	Attributes of bearer capability	5.1.5.2	LN		DISC REL COM
					7.2	LN		REL REL COM
58	011	1010	Bearer capability not presently available	Attributes of bearer capability	5.1.5.2	LN		DISC REL COM
					7.2	LN		REL REL COM
63	011	1111	Service or option not available, unspecified	-	5.1.5.2	LN		DISC REL COM
65	100	0001	Bearer capability not implemented	Attributes of bearer capability	5.1.5.2	LN		DISC REL COM
					6.1	LN		REL COM
66	100	0010	Channel type not implemented	Channel type	No procedure
69	100	0101	Requested facility not implemented	Facility identification	7.1.3.6	RU	DISC REL COM	DISC
					7.1.4.3 7.1.5.3	RN		REL DISC
					7.3	LN		REL REL COM
70	100	0110	Only restricted digital information bearer capability is available	-	No procedure (network dependent option)
79	100	1111	Service or option not implemented, unspecified
81	101	0001	Invalid call reference value	-	5.8.3.2 a)	LU, LN		REL REL COM
					5.8.3.2 b)	LU, LN		REL COM
					5.8.3.2 f)	LU, LN		STAT
82	101	0010	Identified channel does not exist	Channel identity	5.1.4	LN		DISC REL COM
83	101	0011	A suspended call exists, but this call identity does not	-	5.6.5	LN		RES REJ
84	101	0100	Call identity in use	-	5.6.3	LN		SUSP REJ
85	101	0101	No call suspended	-	5.6.5	LN		RES REJ
86	101	0110	Call having the requested call identity has been cleared		5.6.5	LN		RES REJ
88	101	1000	Incompatible destination	Incompatible parameter	5.2.2 5.2.5.1 5.2.5.3 a) B.3.2 B.3.3	RU	REL COM	DISC
91	101	1011	Invalid transit network selection	-	C.2	TN		DISC
						LN		DISC REL REL COM
95	101	1111	Invalid message, unspecified	Message type	5.8	LN		REL COM STAT
96	110	0000	Mandatory information element is missing	Information element identifier(s)	5.8.6.1	LN, LU		REL REL COM STAT
					5.8.11	LN, LU		STAT
97	110	0001	Message type non-existent or not implemented	Message type	5.8.4 5.8.10 5.8.11	LU, LN		STAT
98	110	0010	Message not compatible with call state or message type non-existent or not implemented	Message type	5.8.4	LU, LN		STAT
99	110	0011	Information element non-existent or not implemented	Information element identifier(s)	5.8.7.1 5.8.11	LU, LN		STAT
					5.8.7.1	LN		REL REL COM
100	110	0100	Invalid information element contents	Information element identifier(s)	5.8.6.2	LU, LN		STAT REL REL COM
					5.8.7.2 5.8.11	LU, LN		STAT
101	110	0101	Message not compatible with call state	Message type	5.8.4	LN, LU		STAT
					5.8.11	LN, LU		DISC REL REL COM
102	110	0110	Recovery on time expiry	Timer number	5.2.4 5.2.5.3 5.6.5 5.4.1	LN		DISC
					5.3.3 5.3.4	LN		REL
					5.3.2 f) 5.3.3 5.6.5	LU		REL
111	110	1111	Protocol error, unspecified		5.8.4	RN		DISC
127	111	1111	Interworking, unspecified		No explicit procedure

Appendix I Definition of causes values

Appendix I
Definition of causes values