Yealink SIP-T54S, Administrator'S Manual

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Appendix
1061
6xx Response Supported Notes
603 Decline Yes
604 Does Not Exist Anywhere No
606 Not Acceptable No
SIP Session Description Protocol (SDP) Usage
SDP Headers Supported
v—Session Description Protocol Version Yes
o—Owner/Creator, Session Id Yes
a—Media Attribute Yes
c—Connection Information Yes
b—Bandwidth Information Yes
m—Media Description, name and
address
Yes
s—Session Name Yes
t—Time Description, active time Yes
Appendix I: SIP Call Flows
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—Provisional Responses
SIP 2xx—Successful Responses
SIP 3xx—Redirection Responses
SIP 4xx—Request Failure Responses