Snom ONE IP, Техническое руководство

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Appendix B: SIP Overview 505
Common response codes are shown below (for a complete list, see Table B-8).
Table B-4 Common Responses
Code Definition Occurrence
100 Trying When the other side is trying to process the request
180 Ringing When the other side is ringing
183 Session progress
200 Ok When the event is successful
302 Moved temporarily When forwarding has been activated on the phone
number that is being called
305 Use proxy
400 Bad request When a client enters a bad request
401 Unauthorized When authentication is required
403 Forbidden
404 Not found When a phone number cannot be located
415 Unsupported
media type
When the SDP contains no common codecs (this can
happen if one side supports only G.729 and the PBX
has no G.729 license defined)
500 Server internal
error
When the SIP server is out of resources
501 Not implemented
606 Not acceptable When a global failure occurs (usually at the carrier
level)
Content of Messages
SIP messages consist of the following three parts:
•
SIP URI: The SIP URI is typically built around the user’s phone number.
This first line also indicates either the purpose of the request or the response
given by the called party.