Cisco SIP IP Phone User Manual

B-1
Cisco SIP IP Phone Administrator Guide
APPENDIX B
SIP Call Flows
This chapter includes the following sections:
• Call Flow Scenarios for Successful Calls, page B-1
• Call Flow Scenarios for Failed Calls, page B-46
SIP uses the following request methods:
• INVITE—Indicates that a user or service 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.
• REFER—Indicates that the user (recipient) should contact a third party for use in transferring
parties.
• NOTIFY—Notifies the user of the status of a transfer using REFER. Also used for remote reset.
The following types of responses are used by SIP and generated by the Cisco SIP gateway:
• SIP 1xx—Informational Responses
• SIP 2xx—Successful Responses
• SIP 3xx—Redirection Responses
• SIP 4xx—Client Failure Responses
• SIP 5xx—Server Failure Responses
• SIP 6xx—Global Failure Responses
Call Flow Scenarios for Successful Calls
This section describes call flows for the following scenarios, which illustrate successful calls:
• Gateway-to Cisco SIP IP Phone—Successful Call Setup and Disconnect, page B-2
• Gateway-to-Cisco SIP IP Phone—Successful Call Setup and Call Hold, page B-4
• Cisco SIP IP Phone-to-Cisco SIP IP Phone Simple Call Hold, page B-6

Cisco SIP IP Phone Specifications

General

Brand	Cisco
Model	SIP IP Phone
Category	IP Phone
Language	English