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2N TELEKOMUNIKACE a.s., www.2n.cz
®
The answers to the SIP messages are numerically coded as the case is with the http
protocol. Below are the most important ones:
1XX – information messages (100 – trying, 180 – ringing, 183 – progress);
2XX – successful request completion (200 – OK);
3XX – request forwarding needed (302 – temporarily moved, 305 – use Proxy);
4XX – error (403 – forbidden, 486 – busy here);
5XX – server error (500 – Server Internal Error, 501 – not implemented);
6XX – global failure (606 – not acceptable).
