Below is a list of SIP response codes grouped in 6 response categories.
SIP response codes
- 1xx --Informational Responses
- 2xx --Successful Responses
- 3xx –Redirection Responses
- 4xx –Client Failure Responses
- 5xx –Server Failure Responses
- 6xx –Global Failure Responses
A brief explanation of each response code has been provided below.
During a turn-up, the most common SIP cause code experienced on call failures is SIP 503 – Service
Unavailable
If you experience a SIP 503 on calls sent to our proxy servers (server Ip / port 5060),
please check the following
-
Make
sure that
your
switch
IP address
is included in the
portal
allowed list
under
the Setting tab.
Note that it takes up to 2 hours for IP additions or changes to be processed after you
hit the Save button.
-
Check if your account is active on the portal and make sure that the contract has been accepted.
-
Check if you have funds in your account balance. If not, please replenish your account.
-
Check your dialing pattern on your gateway and make sure that you are following the dialing
plan outlined in the portal Interconnect guide.
If are still not able to complete calls over the SIP interconnection, please open a ticket with our support
group via the portal + include a full SIP trace of a failed call from your switch.
1xx—Informational Responses
100 Trying
Extended search being performed may take a significant time so a forking proxy
must send a 100 Trying response
180 Ringing
Destination user agent received INVITE, and is alerting user of call
181 Call is Being Forwarded
1
Servers can optionally send this response to indicate a call is being forwarded
182 Queued
Indicates that the destination was temporarily unavailable, so the server has
queued the call until the destination is available. A server may send multiple 182
responses to update progress of the queue
183 Session in Progress
This response may be used to send extra information for a call which is still being
set up
2xx—Successful Responses
•
200 OK
•
202 accepted: Indicates that the request has been accepted for processing, but the
processing has not been completed
•
204 No Notification [RFC5839]
3xx—Redirection Responses
•
300 Multiple Choices
•
301 Moved Permanently
•
302 Moved Temporarily
•
305 Use Proxy
•
380 Alternative Service
4xx—Client Failure Responses
400 Bad Request
The request could not be understood due to malformed syntax
401 Unauthorized
The request requires user authentication. This response is issued by UASs and
registrars.
402 Payment Required
Reserved for future use.
403 Forbidden
The server understood the request, but is refusing to fulfill it.
404 Not Found (User not found)
The server has definitive information that the user does not exist at the domain
specified in the Request-URI This status is also returned if the domain in the
Request-URI does not match any of the domains handled by the recipient of the
request.
405 Method Not Allowed
The method specified in the Request-Line is understood, but not allowed for the
address identified by the Request-URI.
406 Not Acceptable
2
The resource identified by the request is only capable of generating response
entities that have content characteristics not acceptable according to the Accept
header field sent in the request.
407 Proxy Authentication Required
The request requires user authentication. This response is issued by proxys
408 Request Timeout
Couldn't find the user in time
409 Conflict
User already registered [RFC2543]
410 Gone
The user existed once, but is not available here any more.
[1]
412 Conditional Request Failed
Conditional Request Failed [RFC3903]
413 Request Entity Too Large
Request body too large
414 Request-URI Too Long
The server is refusing to service the request because the Request-URI is longer
than the server is willing to interpret
415 Unsupported Media Type
Request body in a format not supported
416 Unsupported URI Scheme
Request-URI is unknown to the server
417 Unknown Resource-Priority
Unknown Resource-Priority [RFC4412]
420 Bad Extension
Bad SIP Protocol Extension used, not understood by the server
421 Extension Required
The server needs a specific extension not listed in the Supported header
422 Session Interval Too Small
It is generated by a UAS or proxy when a request contains a Session-Expires
header field with a duration below the minimum timer for the server [RFC4028]
423 Interval Too Brief
Expiration time of the resource is too short
424 Bad Location Information
Bad Location Information [RFC6442]
428 Use Identity Header
Use Identity Header [RFC4474]
429 Provide Referrer Identity
Provide Referrer Identity [RFC3892]
433 Anonymity Disallowed
Anonymity Disallowed [RFC5079]
436 Bad Identity-Info
Bad Identity-Info [RFC4474]
437 Unsupported Certificate
Unsupported Certificate [RFC4474]
438 Invalid Identity Header
3
Invalid Identity Header [RFC4474]
480 Temporarily Unavailable
Callee currently unavailable
481 Call/Transaction Does Not Exist
Server received a request that does not match any dialog or transaction
482 Loop Detected.
Serve has detected a loop
483 Too Many Hops
Max-Forwards header has reach value '0'
484 Address Incomplete
Request-URI incomplete
485 Ambiguous
Request-URI is ambiguous
486 Busy Here
Callee is busy
487 Request Terminated
Request has terminated by bye or cancel
488 Not Acceptable Here
Some aspects of the session description of the Request-URI is not acceptable
489 Bad Event
Bad Event [RFC3265]
491 Request Pending
Server has some pending request from the same dialog
493 Undecipherable
Request contains an encrypted MIME body, which recipient can not decrypt
494 Security Agreement Required
Security Agreement Required [RFC3329]
5xx—Server Failure Responses
•
500 Server Internal Error
•
501 Not Implemented: The SIP request method is not implemented here
•
502 Bad Gateway
•
503 Service Unavailable
•
504 Server Time-out
•
505 Version Not Supported: The server does not support this version of the SIP
protocol
•
513 Message Too Large
•
580 Precondition Failure
6xx—Global Failure Responses
•
600 Busy Everywhere
•
603 Decline
•
604 Does Not Exist Anywhere
4
•
606 Not Acceptable