ISUP - RELEASE CAUSE

ISUP Release Cause Values and their meanings

Meaning

NORMAL EVENT CLASS

1 Unallocated number

2 No route to specified transit network

3 No route to destination

4 Send special information tone

5 Misdialled trunk prefix

6 Channel unacceptable

7 Call awarded and being delivered in an established channel

16 Normal call clearing

17 User busy

18 No user responding

19 No answer from user (user alerted)

20 Subscriber absent

21 Call rejected

22 Number changed

26 Non selected user clearing

27 Destination out of order

28 Invalid format (address incomplete)

29 Facility rejected

30 Response to status enquiry

31 Normal, unspecified

RESOURCE UNAVAILABLE CLASS

34 No circuit/channel available

38 Network out of order

41 Temporary failure

42 Switching equipment congestion

43 Access information discarded

44 Request circuit/channel not available

47 Resource unavailable, unspecified

SERVICE/OPTION NOT AVAILABLE CLASS

49 Quality of service unavailable

50 Requested facility not subscribed

55 Incoming calls barred within CUG

57 Bearer capability not authorized

58 Bearer capability not presently available

63 Service or option not available, unspecified

SERVICE/OPTION NOT IMPLEMENTED CLASS

65 Bearer capability not implemented

69 Requested facility not implemented 13000

70 Only restricted digital information bearer capability is available

79 Service or option not implemented, unspecified

INVALID MESSAGE CLASS

81 Invalid call reference value

82 Identified channel does not exist

83 A suspend call existing but this call identity does not

84 Call identity in use

85 No call suspended

86 Call having the requested call identity has been cleared

87 User not member of CUG

88 Incompatible destination

91 Invalid transit network selection

95 Invalid message, unspecified

PROTOCOL ERROR CLASS

96 Mandatory information element is missing

97 Message type non-existing or not implemented

98 Message not compatible with call state or message type non-existing or not implemented

99 Information element non-existing or not implemented

100 Invalid information element contents

101 Message not compatible call state

102 Recovery on timer expiry

103 Parameter non-existent or not implemented

109 Unrecognized message has been passed on

110 Message with unrecognized parameter discarded

111 Protocol error, unspecified

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