B-2
SIP Request Messages
SIP Request Messages
Supported SIP
Request Messages The VOCAL system supports these SIP request messages:
Table B-1. SIP Request Messages Descriptions
SIP Request
Messages Descriptions
INVITE Indicates that the user or service is being invited to
participate in a session.
ACK Confirms that the client has received a final
response to an INVITE request.
BYE Indicate the user wishes to terminate the call.
CANCEL Cancels a pending request but does not affect a
completed request.
REGISTER Register the address listed in the To header field
with a SIP server.
OPTIONS Queries the capability of the servers.
INFO Allows for the carrying of the session related
control information that is generated during a
session.