Fixed Mapping of ISDN Release Reason to SIP Response
The following table shows the mapping of ISDN release reason to SIP response.
Mapping of ISDN Release Reason to SIP Response
| ISDN Release Reason | Description | SIP Response | Description | 
|---|---|---|---|
| 1 | Unallocated number | 404 | Not found | 
| 2 | No route to network | 404 | Not found | 
| 3 | No route to destination | 404 | Not found | 
| 4 | Send Special Information Tone | 400 | Bad Request | 
| 5 | Misdialed Trunk Prefix | 400 | Bad Request | 
| 6 | Channel unacceptable | 406* | Not acceptable | 
| 7 | Call awarded and being delivered in an established channel | 500 | Server internal error | 
| 8 | Preemption | 480 | Temporarily unavailable | 
| 9 | Preemption - Circuit Reserved for Reuse | 488 | Not Acceptable Here | 
| 16 | Normal call clearing | -* | BYE | 
| 17 | User busy | 486 | Busy here | 
| 18 | No user responding | 408 | Request timeout | 
| 19 | No answer from the user | 480 | Temporarily unavailable | 
| 21 | Call rejected | 403 | Forbidden | 
| 22 | Number changed w/o diagnostic | 410 | Gone | 
| 23 | Redirection | 400 | Bad Request | 
| 25 | Exchange Routing Error | 400 | Bad Request | 
| 26 | Non-selected user clearing | 404 | Not found | 
| 27 | Destination out of order | 502 | Bad gateway | 
| 28 | Address incomplete | 484 | Address incomplete | 
| 29 | Facility rejected | 501 | Not implemented | 
| 30 | Response to status enquiry | 501* | Not implemented | 
| 31 | Normal unspecified | 480 | Temporarily unavailable | 
| 32 | Circuit Congestion | 500 | Server internal error | 
| 33 | User Congestion | 500 | Server internal error | 
| 34 | No circuit available | 503 | Service unavailable | 
| 38 | Network out of order | 503 | Service unavailable | 
| 39 | Permanent Frame Mode Connection Out-of-Service | 503 | Service unavailable | 
| 40 | Permanent Frame Mode Connection Operational | 503 | Service unavailable | 
| 41 | Temporary failure | 503 | Service unavailable | 
| 42 | Switching equipment congestion | 503 | Service unavailable | 
| 43 | Access information discarded | 502* | Bad gateway | 
| 44 | Requested channel not available | 503* | Service unavailable | 
| 46 | Precedence Call Blocked | 488 | Not Acceptable Here | 
| 47 | Resource unavailable | 503 | Service unavailable | 
| 49 | QoS unavailable | 503* | Service unavailable | 
| 50 | Facility not subscribed | 503* | Service unavailable | 
| 53 | Outgoing Calls Barred within CUG | 488 | Not Acceptable Here | 
| 55 | Incoming calls barred within CUG | 403 | Forbidden | 
| 57 | Bearer capability not authorized | 403 | Forbidden | 
| 58 | Bearer capability not presently available | 503 | Service unavailable | 
| 62 | Inconsistency In Outgoing Information Element | 503 | Service unavailable | 
| 63 | Service/option not available | 503* | Service unavailable | 
| 65 | Bearer capability not implemented | 501 | Not implemented | 
| 66 | Channel type not implemented | 480* | Temporarily unavailable | 
| 69 | Requested facility not implemented | 503* | Service unavailable | 
| 70 | Only restricted digital information bearer capability is available | 503* | Service unavailable | 
| 79 | Service or option not implemented | 501 | Not implemented | 
| 81 | Invalid call reference value | 502* | Bad gateway | 
| 82 | Identified channel doesn't exist | 502* | Bad gateway | 
| 83 | Suspended call exists, but this call identity doesn't | 503* | Service unavailable | 
| 84 | Call identity in use | 503* | Service unavailable | 
| 85 | No call suspended | 503* | Service unavailable | 
| 86 | Call having the requested call identity has been cleared | 408* | Request timeout | 
| 87 | User not member of CUG | 503 | Service unavailable | 
| 88 | Incompatible destination | 503 | Service unavailable | 
| 90 | Non-Existent CUG | 503 | Service unavailable | 
| 91 | Invalid transit network selection | 502* | Bad gateway | 
| 95 | Invalid message | 503 | Service unavailable | 
| 96 | Mandatory information element is missing | 409* | Conflict | 
| 97 | Message type non-existent or not implemented | 480* | Temporarily not available | 
| 98 | Message not compatible with call state or message type non-existent or not implemented | 409* | Conflict | 
| 99 | Information element non-existent or not implemented | 480* | Not found | 
| 100 | Invalid information elements contents | 501* | Not implemented | 
| 101 | Message not compatible with call state | 503* | Service unavailable | 
| 102 | Recovery of timer expiry | 408 | Request timeout | 
| 103 | Parameter Non-Existent Or Not Implemented - Passed On | 400 | Bad Request | 
| 110 | Message With Unrecognized Parameter Discarded | 400 | Bad Request | 
| 111 | Protocol error | 500 | Server internal error | 
| 112 | Uknown Error | 400 | Bad Request | 
| 127 | Interworking unspecified | 500 | Server internal error | 
* Messages and responses were created because the ‘ISUP to SIP Mapping’ draft doesn’t specify their cause code mapping.