What are call status codes?

What are call status codes?


In VOIP telephony every call has a status i.e.., Answered, Busy, No Answer or Failed. While it is pretty straightforward for calls with status ‘Answered’ or ‘Busy’, there could be various reasons for calls with status ‘No Answer’ and ‘Failed’

The International Telecommunication Union has defined certain codes to further define various reasons for the call status. These codes are called Call Hang-up Codes (HGC). These codes are particularly useful for calls with status ‘No Answer’ and ‘Failed’. It helps the advanced users/technicians/IT personnel to easily identify the reason and take an appropriate action.

Normally received call status codes

  1. Failed 0 – Network issues from the call receiving end when no other code is applicable
  2. Failed 1 – Call failed. Most likely the number is not in use or is an unallocated number ((On the softphone it will show up as SIP response 404)
  3. Answered 16 – Call has been answered successfully
  4. Busy 17 – User on the dialled number is busy ((On the softphone it will show up as SIP response 486)
  5. Failed 18 – Thiscause is used when a called party does not respond to a call establishment message with either an alerting or connect indication within the prescribed period of time allocated ((On the softphone it will show up as SIP response 408)
  6. No Answer 19  or Busy 19 – User is alerted but there is no response from the call recipient. This happens when the device is malfunctioning or some network issues that does not allow signalling to reach the network ((On the softphone it will show up as SIP response 480)
  7. Failed 20 - Subscriber Absent. This cause value is used when a mobile station has logged off, radio contact is not obtained with a mobile station or if a personal telecommunication user is temporarily not addressable at any user-network interface. Sofia SIP will normally raise USER_NOT_REGISTERED in such situations ((On the softphone it will show up as SIP response 480)
  8. Failed 21 - This cause indicates that the equipment sending this cause does not wish to accept this call, although it could have accepted the call because the equipment sending this cause is neither busy nor incompatible ((On the softphone it will show up as SIP response 603)
  9. Failed 34 - This cause indicates that there is no appropriate circuit/channel presently available to handle the call (On the softphone it will show up as SIP response 503)
  1. Failed 203 – No rates for User
  2. Failed 204 – No suitable providers found
  3. Failed 207 – Not clear who should receive call
  4. Failed 210 – Balance more than 0, but not enough to make call
  5. Failed 211 – Low balance for user or Daily limit is reached
  6. Failed 212 – Balance too low for more simultaneous calls
  7. Failed 219 – DID has reached call limit. No more calls allowed to this DID
  8. Failed 220 – User call limit reached
  9. Failed 221 – Device call limit reached
  10. Failed 224 – Provider skipped because his rate is higher than user’s rate
  11. Failed 225 – CallerID is banned
  12. Failed 229 – DID is reserved
  13. Failed 230 – Connection returned error code 0 instead of real code
  14. Failed 239 – Device used its daily call time limit
  15. Failed 240 – Provider belongs to the User which makes call (loop)
  16. Failed 241 – Caller canceled the call before call was answered
  17. Failed 246 – Duplicate call hangup
  18. Failed 248 – Call was terminated because FAS(False Answer Supervision) control detected an issue
  19. Failed 255 – Destination is in blacklist
  20. Failed 256 – Destination is not in whitelist
  21. Failed 257 – Calling Card expired
  22. Failed 258 – Calling Card is not sold yet
  23. Failed 259 – Calling Card is empty
  24. Failed 260 – Destination is blocked in User’s Tariff
  25. Failed 262 – Caller ID number is in blacklist
  26. Failed 263 – Caller ID is not in whitelist
  27. Failed 265 – Provider skipped because rate margin is lower than allowed
  28. Failed 268 – PDD limit reached
  29. Failed 269 – User’s call rate is higher than allowed
  30. Failed 277 – CallerID is in Global Blacklist
  31. Failed 278 – CallerID is not in Global Whitelist
  32. Failed 279 – Destination number is in Global Blacklist
  33. Failed 280 – Destination number is not in Global Whitelist
  34. Failed 283 – Caller ID is in DID blacklist
  35. Failed 284 – DID is closed
  36. Failed 287 – Low balance for Device

Further information

For further explanation refer to the following links - 
  1. From Avaya
  2. From Sangoma
  3. From Freeswitch

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