1;Unallocated (unassigned) 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 8;Preemption 9;Preemption – circuit reserved for reuse 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 23;Redirection to new destination 25;Exchange routing error 26;Non-selected user clearing 27;Destination out of order 28;Invalid number format (address incomplete) 29;Facility rejected 30;Response to STATUS ENQUIRY 31;Normal, unspecified 34;No circuit/channel available 38;Network out of order 39;Permanent frame mode connection out of service 40;Permanent frame mode connection operational 41;Temporary failure 42;Switching equipment congestion 43;Access information discarded 44;Requested circuit/channel not available 46;Precedence call blocked 47;Resource unavailable, unspecified 49;Quality of service not available 50;Requested facility not subscribed 53;Outgoing calls barred within CUG 55;Incoming calls barred within CUG 57;Bearer capability not authorized 58;Bearer capability not presently available 62;Inconsistency in designated outgoing access information and subscriber class 63;Service or option not available, unspecified 65;Bearer capability not implemented 66;Channel type not implemented 69;Requested facility not implemented 70;Only restricted digital information bearer capability is available 79;Service or option not implemented, unspecified 81;Invalid call reference value 82;Identified channel does not exist 83;A suspended call exists, 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 90;Non-existent CUG 91;Invalid transit network selection 95;Invalid message, unspecified 96;Mandatory information element is missing 97;Message type non-existent or not implemented 98;Message not compatible with call state or message type non-existent or not implemented 99;Information element /parameter non-existent or not implemented 100;Invalid information element contents 101;Message not compatible with call state 102;Recovery on timer expiry 103;Parameter non-existent or not implemented, passed on 110;Message with unrecognized parameter, discarded 111;Protocol error, unspecified 127;Interworking, unspecified