SIP Requests

From VoIP.ms Wiki

Article en Français	Artículo en Español
Français	Español

In this article we are going to provide the description of each SIP Requests. Which are the codes used by SIP (Session Initiation Protocol) for communication. SIP Responses complement these SIP Requests, which generally indicate whether the request is a successful or a failed one, and in a latter case, why it failed.

SIP requests

  Request name	                Description	                                              Defined in
  INVITE	Indicates a client is being invited to participate in a call session.	        RFC 3261
  ACK	        Confirms that the client has received a final response to an INVITE request.	RFC 3261
  BYE	        Terminates a call and can be sent by either the caller or the callee.	        RFC 3261
  CANCEL	Cancels any pending request.	                                                RFC 3261
  OPTIONS	Queries the capabilities of servers.	                                        RFC 3261
  REGISTER	Registers the address listed in the To header field with a SIP server.	        RFC 3261
  PRACK	        Provisional acknowledgement.	                                                RFC 3262
  SUBSCRIBE	Subscribes for an Event of Notification from the Notifier.	                RFC 3265
  NOTIFY	Notify the subscriber of a new Event.	                                        RFC 3265
  PUBLISH	Publishes an event to the Server.	                                        RFC 3903
  INFO	        Sends mid-session information that does not modify the session state.	        RFC 6086
  REFER	        Asks recipient to issue SIP request (call transfer.)	                        RFC 3515
  MESSAGE	Transports instant messages using SIP.	                                        RFC 3428
  UPDATE	Modifies the state of a session without changing the state of the dialog.	RFC 3311