HP-UX C SIP Stack Programmer's Guide (Novembery 2007)

74 HP-UX C SIP Stack Programmer’s Guide

Call-leg PRACK State Machine

AUTHENTICATING A

E-INVITE

When a re-INVITE procedure is ended with a 401 or 407 final response, the

application needs to re-send the re-INVITE with authentication information. In

this case, the RVSIP_CALL_LEG_MODIFY_STATE_ACK_SENT state will

have the RVSIP_CALL_LEG_REASON_AUTH_NEEDED reason. The

application should repeat the process of sending the re-INVITE, (prepare the

outbound message, and call the RvSipCallLegReInviteCreate() and

RvSipCallLegReInviteRequest() functions again). The call-leg will

automatically add the needed authentication information (credentials) to the new

outgoing re-INVITE, and the request will be sent to the remote party. For more

information on the authentication process, see the Authentication chapter.

CALL-LEG PRACK

TATE MACHINE

The Call-leg PRACK state machine represents the state of a PRACK process

between two SIP User Agents. A PRACK process starts when the UAS triggers

a reliable provisional response in the OFFERING or REINVITE_RCVD states.

The RvSipCallLegPrackStateChangedEv() callback reports call-leg PRACK

state changes and state change reasons.

The application can work in automatic or manual PRACK modes. In automatic

mode, a PRACK request will be sent automatically on receipt of reliable

provisional response. When a PRACK request is received, the SIP Stack will

automatically send the response. In manual mode, the application should use the

PRACK state machine and the Call-leg PRACK API to trigger the PRACK

request and response. To work in manual PRACK mode, you should set the

manualPrack configuration parameter to RV_TRUE when the SIP Stack

initializes.

The call-leg associates with the following PRACK states:

RVSIP_CALL_LEG_PRACK_STATE_UNDEFINED

There is currently no active PRACK process.

RVSIP_CALL_LEG_PRACK_STATE_REL_PROV_RESPONSE_RCVD

A reliable provisional response was received.

RVSIP_CALL_LEG_PRACK_STATE_PRACK_SENT

A PRACK request was sent.

RVSIP_CALL_LEG_PRACK_STATE_PRACK_FINAL_RESPONSE_RCVD

A PRACK final response was received.