Filter
Top Products
184 Dialogic
®
Global Call IP Technology Guide — November 2007
Dialogic Corporation
IP-Specific Operations
string that is the complete header field to be sent, starting with the header field name and including
all required syntax elements and punctuation.
As permitted in RFC 3261 and other IETF standards, applications can insert multiple header fields
of the same type with different values, or can insert a single header field with multiple values in a
comma-delimited string.
When an optional or proprietary header field is being set, the IP call control library and SIP stack
simply pass through the header contents as specified by the application. The library and stack
check for the presence of all header fields that are required for a specific SIP request or reply, and if
such a required field is being set by the application, there may be some level of validation
performed, as well. Further details regarding validation and error checking will be provided in
future revisions of this document.
Note: Setting SIP message header information requires a detailed knowledge of the SIP protocol and its
relationship to Dialogic
®
Global Call API. The application has the responsibility to ensure that the
correct SIP message information is set before calling the appropriate Dialogic
®
Global Call API
function to send the message.
Note that header-specific Global Call parameter IDs exist for some standard SIP header fields, but
that there is no advantage to using the those parameters when setting SIP headers if the parameter
accesses a complete header field. Parameters that access only a part of the corresponding header
field (i.e., just the URI or just the display string) may provide some convenience, but this approach
is not recommended because all of the header-specific parameter defines are being deprecated.
Table 11 identifies the parameter IDs that provide access to partial header fields.
The following code snippet shows how to set the Request-URI header information before issuing
gc_MakeCall( ). This translates to a SIP INVITE message with the specified Request-URI.
Table 11. Parameter IDs for Partial Header Field Access (Deprecated)
Header Field Name Set ID and Parameter ID Maximum Data Length Define †
Contact display string IPSET_SIP_MSGINFO
• IPPARM_CONTACT_DISPLAY
IP_CONTACT_DISPLAY_MAXLEN
Contact URI IPSET_SIP_MSGINFO
• IPPARM_CONTACT_URI
IP_CONTACT_URI_MAXLEN
Diversion URI IPSET_SIP_MSGINFO
• IPPARM_DIVERSION_URI
IP_DIVERSION_MAXLEN
From display string IPSET_SIP_MSGINFO
• IPPARM_FROM_DISPLAY
IP_FROM_DISPLAY_MAXLEN
Replaces (parameter in
Refer-To header field for
attended call transfers)
IPSET_SIP_MSGINFO
• IPPARM_REPLACES
IP_REPLACES_MAXLEN
To display string IPSET_SIP_MSGINFO
• IPPARM_TO_DISPLAY
IP_TO_DISPLAY_MAXLEN
† The value for each listed parameter ID is a character array with the maximum size of the array (including the NULL) equal to
the corresponding maximum length define, all of which are equated to 255.