SIP Messages
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SIPxNano IP-PBX Getting Started Guide
A • Session Initiation Protocol (SIP)
SIP Phones support these SIP methods:
Response Codes
SIP response codes indicate the status of a session. Response codes are generated and sent in outgoing mes-
sages, and accepted when received in incoming messages.
Responses with a 1xx response code are also called provisional responses, while the remaining response codes
(2xx, 3xx, 4xx, 5xx, and 6xx) indicate final responses.
Refer to Request for Comments 3261 for standard SIP status code definitions. Additional codes may also be
listed in Internet Draft draft-ietf-sip-rfc2543bis-05.txt.
Table 8. Supported Methods
Methods Initiated
Methods Received
INVITE
INVITE
ACK
ACK
BYE
BYE
REFER
REFER
CANCEL
CANCEL
REGISTER
OPTIONS
OPTIONS
NOTIFY
NOTIFY
SUBSCRIBE
Table 9. Response codes
Code Function
1xx
Informational: trying, ringing, forwarding, queuing, in progress
2xx
Successful: Ok
3xx
Redirection: indicate additional information for call forwarding
4xx
Request Failure: indicate request errors such as missing information
5xx
Server Failure: time outs, unavailable services, and other server errors
6xx
Global Failures: busy, declined, not found, not acceptable