Dialogic 05-2239-009 User Manual

When the SIP stack receives a SIP NOTIFY request, the Dialogic

®

 Global Call API library 

generates an Extension event (GCEV_EXTENSION) of type IPEXTID_RECEIVEMSG. 

The data associated with this Extension event contains a parameter element as follows:

IPSET_MSG_SIP

IPPARM_MSGTYPE

value = IP_MSGTYPE_SIP_NOTIFY 

Both subscribed and unsubscribed NOTIFY requests can be received; in the case of a subscribed 
NOTIFY, the value of the Call-ID header field will match the Call-ID of a previously sent 
SUBSCRIBE request.

The application can use the techniques described in 

 to retrieve message header fields of interest, including:

To display string 

From display string 

Event header field 

Call-ID header field 

If the message has a body, the application can extract the MIME-encoded information using the 
techniques described in 

. 

The application must retrieve the necessary SIP message header and body information by copying 
the data into its own buffer before the next call to gc_GetMetaEvent( ). Once the next 
gc_GetMetaEvent( ) call is issued, the message information is no longer available from the 
metaevent buffer. 

A code example that illustrates the general procedure for retrieving information from all incoming 
messages associated with the SUBSCRIBE and NOTIFY methods is included in 

, on page 225.

Once an application has received a GCEV_EXTENSION event for a SIP NOTIFY message (either 
subscribed or unsubscribed) and extracted the information from the event, it must send a response 
message. 

The response is sent as an Extension message using the following parameter element in the 
parameter block:

IPSET_MSG_SIP

IPPARM_MSGTYPE
and one of the following two parameter values:

IP_MSGTYPE_SIP_NOTIFY_ACCEPT

IP_MSGTYPE_SIP_NOTIFY_REJECT