V7122 Gateway User Guide 455Fixed Mapping of ISDN Release Reason to SIP ResponseTable 97 describes the mapping of ISDN release reason to SIP response.Table 97 Mapping of ISDN Release Reason to SIP ResponseISDN ReleaseReason Description SIPResponse Description1 Unallocated number 404 Not found2 No route to network 404 Not found3 No route to destination 404 Not found6 Channel unacceptable 406* Not acceptable7 Call awarded and being delivered in anestablished channel 500 Server internal error16 Normal call clearing -* BYE17 User busy 486 Busy here18 No user responding 408 Request timeout19 No answer from the user 480 Temporarily unavailable20 Subscriber absent 480 Temporarily unavailable21 Call rejected 403 Forbidden22 Number changed w/o diagnostic 410 Gone22 Number changed with diagnostic 410 Gone23 Redirection to new destination 480 Temporarily unavailable26 Non-selected user clearing 404 Not found27 Destination out of order 502 Bad gateway28 Address incomplete 484 Address incomplete29 Facility rejected 501 Not implemented30 Response to status enquiry 501* Not implemented31 Normal unspecified 480 Temporarily unavailable34 No circuit available 503 Service unavailable38 Network out of order 503 Service unavailable*Messages and responses were created since the ‘ISUP to SIP Mapping’ draft doesn’t specifytheir cause code mapping.
