2N VoiceBlue Lite - Manual v2.6 - Manual (Page 46)

• CANCEL – termination of non-established connection;
• REGISTER – UA registration in SIP Proxy;
• OPTIONS – inquiry of server options.
Replies to SIP messages are in the digital format like in the http
protocol. Here are the most important ones:
• 1XX – information messages (100 – Trying, 180 – Ringing,
183 - Progress);
• 2XX – successful request completion (200 – OK);
• 3XX – call forwarding, the inquiry should be directed
elsewhere (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);
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