The SIP protocol defines some common request types:
Table 1–1 Common SIP Requests|
SIP Request |
Description |
|---|---|
|
INVITE |
initiate a session between two participants |
|
ACK |
the client acknowledges receiving the final message from an INVITE request |
|
BYE |
terminates a connection |
|
CANCEL |
cancels any pending actions, but does not terminate any accepted connections |
|
OPTIONS |
queries the server for a list of capabilities |
|
REGISTER |
registers the address in the To header with the server |
SIP requests are codes used to indicate the various stages in a connection between SIP-enabled entities.
See SIP Requests for a list of all SIP requests.