Solarius

1xx: Provisional — request received, continuing to process the request;

Provisional responses, also known as informational responses, indicate that the server contacted is performing some further action and does not yet have a definitive response. A server sends a 1xx response if it expects to take more than 200 ms to obtain a final response. Note that 1xx responses are not transmitted reliably. They never cause the client to send an ACK. Provisional (1xx) responses MAY contain message bodies, including session descriptions.

• 100 Trying
• 180 Ringing
• 181 Call Is Being Forwarded
• 182 Queued
• 183 Session Progress

2xx: Success — the action was successfully received, understood, and accepted;

• 200 OK
• 202 accepted: Used for referrals

3xx: Redirection — further action needs to be taken in order to complete the request;

• 300 Multiple Choices
• 301 Moved Permanently
• 302 Moved Temporarily
• 305 Use Proxy
• 380 Alternative Service

4xx: Client Error — the request contains bad syntax or cannot be fulfilled at this server;

• 400 Bad Request
• 401 Unauthorized: Used only by registrars. Proxys should use proxy authorization 407
• 402 Payment Required (Reserved for future use)
• 403 Forbidden
• 404 Not Found: User not found
• 405 Method Not Allowed
• 406 Not Acceptable
• 407 Proxy Authentication Required
• 408 Request Timeout: Couldn’t find the user in time
• 409 Conflict
• 410 Gone: The user existed once, but is not available here any more
• 413 Request Entity Too Large
• 414 Request-URI Too Long
• 415 Unsupported Media Type
• 416 Unsupported URI Scheme
• 420 Bad Extension: Bad SIP Protocol Extension used, not understood by the server
• 421 Extension Required
• 423 Interval Too Brief
• 480 Temporarily Unavailable
• 481 Call/Transaction Does Not Exist
• 482 Loop Detected
• 483 Too Many Hops
• 484 Address Incomplete
• 485 Ambiguous
• 486 Busy Here
• 487 Request Terminated
• 488 Not Acceptable Here
• 491 Request Pending
• 493 Undecipherable: Could not decrypt S/MIME body part

5xx: Server Error — the server failed to fulfill an apparently valid request;

• 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

6xx: Global Failure — the request cannot be fulfilled at any server.

• 600 Busy Everywhere
• 603 Decline
• 604 Does Not Exist Anywhere
• 606 Not Acceptable