Appendix M. Cause Values
Table M-1 lists the ITU-T cause values. Table M-2 lists additional cause values that are specific to ANSI networks. The cause value, which is included as a field in each ISUP REL message, indicates the reason a call was released. Bits 1 through 4 indicate the value within each cause class, while bits 5 through 7 indicate the class.
Table M-1. ITU-T Cause Values
Cause Values | Definition |
|---|---|
Normal Class | |
0 0 0 0 0 0 1 | Unallocated (unassigned) number |
0 0 0 0 0 1 0 | No route to specified transit network |
0 0 0 0 0 1 1 | No route to destination |
0 0 0 0 1 0 0 | Send special information tone |
0 0 0 0 1 0 1 | Misdialed trunk prefix |
0 0 0 0 1 1 0 | Channel unacceptable |
0 0 0 0 1 1 1 | Call awarded and being delivered in an established channel |
0 0 0 1 0 0 0 | Preemption ... |
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