SIP Request Methods Response Codes

SIP Request Methods Response Codes.

SIP Request Methods

There are several different Request methods to server different purposes. SIP borrowed headers and body format from the protocol HTTP. Like HTTP SIP also has different methods. following table will describe those request methods

 

SIP Request Methods
S.No Method Description
1 REGISTER Registers to receive inbound calls on registrar or SIP server
2 INVITE Established a new session
3 ACK Confirms that message/request has been received
4 BYE Ends Session
5 CANCEL Cancels establishing session
6 OPTIONS Queries capabilities of server
7 PARK Provisional Acknowledgement
8 SUBSCRIBE Subsribes for an Notifications from the Notifier
9 NOTIFY Notify the subscriber a new Event
10 PUBLISH Publish and event to the Server
11 INFO Sends mid-session information
12 REFERER Asks the recipient to issue call transfer
13 MESSAGE Transport Insant Message
14 UPDATE Modifies the state of a session without changing the state of the dialog.

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SIP Responses

Like I mentioned earlier, SIP protocol borrowed few things from protocol HTTP. SIP borrowed response code from HTTP. Most of response codes are similar to HTTP and  SIP extends them codes to 6xx.

SIP Response Codes
S.No Code Description
1 1xx Informational responses
2 2xx Success Responses
3 3xx Redirect Responses
4 4xx Request Failure/Client Error
5 5xx Server Error
6 6xx Global Failures