ISDN and SIP Codes



Carrier Implementations

Unfortunately although the standards exist for how these codes should be implemented, the reality (globally) is that carriers all differ, and will return different codes for the same scenarios.

This is something we try to normalize but is not a simple task. The dialer and Click2Dial v2.3.0+ are much more advanced in this regards and does a lot more work to normalize the data then Click2Dial pre v2.3.0.



Prefer Dispositions to ISDN codes, they may not vary as much, but are more accurate because we handle the mapping and normalizing for you.



Code

ISDN Cause codes (Q.850 & Q.931 unless specified)

SIP/PJSIP (RFC 3261)

Motif

Code

ISDN Cause codes (Q.850 & Q.931 unless specified)

SIP/PJSIP (RFC 3261)

Motif



Cause not defined





1

Unallocated (unassigned) number

404, 485, 604



2

No route to specified transmit network

404



3

No route to destination

404, 420



5

Misdialled trunk prefix (national use)





6

Channel unacceptable





7

Call awarded and being delivered in an established channel





8

ISUP - Preemption





14

QoR: ported number





16

Normal Clearing

200, 202, 204

gone, success

17

User busy

486

busy

18

No user responding

408

expired

19

No answer from user (user alerted)

480, 483



20

Subscriber absent

480



21

Call Rejected

401, 403, 407, 603

cancel, decline

22

Number changed

410



23

Redirected to new destination

410



26

Non-selected user clearing

(ASTERISK-15057)

404



27

Destination out of order

502



28

Invalid number format

484



29

Facility rejected

501



30

Response to STATUS ENQUIRY





31

Normal, unspecified

480

Temporarily unavailable

34

No circuit/channel available

(Note that we've called this "Circuit/channel congestion" for a while which can cause confusion with code 42)

503

general-error

38

Network out of order

500, 503



41

Temporary failure

409, 503



42

Switching equipment congestion

503

failed-application

43

Access information discarded





44

Requested circuit/channel not available





47

Resource unavailable

503

 

50

Requested facility not subscribed





52

Outgoing call barred





54

Incoming call barred





55

incoming calls barred within CUG

403

 

57

Bearer capability not authorized

403



58

Bearer capability not presently available

488, 606

incompatible-parameters, media-error, unsupported-applications

65

Bearer capability not implemented





66

Channel type not implemented





69

Requested facility not implemented



unsupported-transports

70

only restricted digital available

488

 

79

service or option not implemented

501

 

81

Invalid call reference value





87

user not member of CUG

403

 

88

Incompatible destination

503



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 nonexistent or not implemented





100

Invalid information element contents





101

Message not compatible with call state





102

Recover on timer expiry

504

timeout

?

Mandatory IE length error





111

Protocol error, unspecified

500

failed-transport, security-error

127

Interworking, unspecified

4xx, 505, 6xx

connectivity-error


Sources