Yealink SIP-T2 Series Administrator's Manual page 499

6xx Response—Global Responses
6xx Response
600 Busy Everywhere
603 Decline
604 Does Not Exist Anywhere
606 Not Acceptable
SDP Headers
v—Protocol version
o—Owner/creator and session
identifier
a—Media attribute
c—Connection information
m—Media name and transport
address
s—Session name
t—Active time
SIP uses six request methods:
INVITE—Indicates a user is being invited to participate in a call session.
ACK—Confirms that the client has received a final response to an INVITE request.
BYE—Terminates a call and can be sent by either the caller or the callee.
CANCEL—Cancels any pending searches but does not terminate a call that has
already been accepted.
OPTIONS—Queries the capabilities of servers.
REGISTER—Registers the address listed in the To header field with a SIP server.
The following types of responses are used by SIP and generated by the IP phone or the
SIP server:
SIP 1xx—Informational Responses
SIP 2xx—Successful Responses
Supported
Yes
Yes
No
No
Supported
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Appendix
Notes
487