| Provisional 1xx |
| 100 |
Trying |
RFC3261 |
| 180 |
Ringing |
RFC3261 |
| 181 |
Call is being forwarded |
RFC3261 |
| 182 |
Queued |
RFC3261 |
| 183 |
Session in progress |
RFC3261 |
| Successful 2xx |
| 200 |
OK |
RFC3261 |
| 202 |
Accepted |
RFC3265 |
| Redirection 3xx |
| 300 |
Multiple choices |
RFC3261 |
| 301 |
Moved permanently |
RFC3261 |
| 302 |
Moved temporarily |
RFC3265 |
| 305 |
Use proxy |
RFC3261 |
| 380 |
Alternative service |
RFC3261 |
| Request failure 4xx |
| 400 |
Bad request |
RFC3261 |
| 401 |
Unauthorized |
RFC3261 |
| 402 |
Payment required |
RFC3261 |
| 403 |
Forbidden |
RFC3261 |
| 404 |
Not found |
RFC3261 |
| 405 |
Method not allowed |
RFC3261 |
| 406 |
Not acceptable |
RFC3261 |
| 407 |
Proxy authentication required |
RFC3261 |
| 408 |
Request timeout |
RFC3261 |
| 410 |
Gone |
RFC3261 |
| 412 |
Conditional request failed |
RFC3903 |
| 413 |
Request entity too large |
RFC3261 |
| 414 |
Request-URI too long |
RFC3261 |
| 415 |
Unsupported media type |
RFC3261 |
| 416 |
Unsupported URI scheme |
RFC3261 |
| 417 |
Unknown resource-priority |
RFC4412 |
| 420 |
Bad extension |
RFC3261 |
| 421 |
Extension required |
RFC3261 |
| 422 |
Session interval too small |
RFC4028 |
| 423 |
Interval too brief |
RFC3261 |
| 428 |
Use identity header |
RFC4474 |
| 429 |
Provide referrer identity |
RFC3892 |
| 436 |
Bad identity-info |
RFC4474 |
| 437 |
Unsupported certificate |
RFC4474 |
| 438 |
Invalid identity header |
RFC4474 |
| 480 |
Temporarily unavailable |
RFC3261 |
| 481 |
Call/Transaction does not exist |
RFC3261 |
| 482 |
Loop detected |
RFC3261 |
| 483 |
Too many hops |
RFC3261 |
| 484 |
Address incomplete |
RFC3261 |
| 485 |
Ambiguous |
RFC3261 |
| 486 |
Busy here |
RFC3261 |
| 487 |
Request terminated |
RFC3261 |
| 488 |
Not acceptable here |
RFC3261 |
| 489 |
Bad event |
RFC3265 |
| 491 |
Request pending |
RFC3261 |
| 493 |
Undecipherable |
RFC3261 |
| 494 |
Security agreement required |
RFC3329 |
| Server failure 5xx |
| 500 |
Server internal error |
RFC3261 |
| 501 |
Not implemented |
RFC3261 |
| 502 |
Bad gateway |
RFC3261 |
| 503 |
Service unavailable |
RFC3261 |
| 504 |
Server time-out |
RFC3261 |
| 505 |
Version not supported |
RFC3261 |
| 513 |
Message too large |
RFC3261 |
| 580 |
Precondition failure |
RFC3312 |
| Global failures 6xx |
| 600 |
Busy everywhere |
RFC3261 |
| 603 |
Decline |
RFC3261 |
| 604 |
Does not exist anywhere |
RFC3261 |
| 606 |
Not acceptable |
RFC3261 |