Global Call API for HMP on Windows Programming Guide — August 2006 93
Call Control
7.3 Resource Routing
The Global Call routing functions use the device handles of resources such as a voice channel, a
media resource, or a network time slot. The gc_GetResourceH( ) function can be used to obtain
the network, media and voice device handles, associated with the specified line device.
The gc_GetResourceH( ) function, with a resourcetype of GC_MEDIADEVICE returns the
media device handle for the specified line device.
The gc_GetResourceH( ) function, with a resourcetype of GC_NETWORKDEVICE returns the
network device handle for the specified line device.
The gc_GetResourceH() function, with a resourcetype of GC_VOICEDEVICE, returns the voice
device handle only if the specified line device has a voice, media, or tone resource associated with
it, for example, if a voice channel was specified in the gc_OpenEx() function devicename
parameter, or if the voice channel was subsequently attached to the line device and has remained
attached to that line device.
Refer to the appropriate Global Call Technology Guide for technology-specific information on
routing resources when using the gc_OpenEx( ) function to specify a voice or media resource, or
when using the gc_AttachResource( ) function to associate a voice or media resource with a
Global Call line device.
7.4 Feature Transparency and Extension
Global Call Feature Transparency and Extension (FTE) provides a common interface to multiple
network interface specific libraries for features that are abstracted across multiple call control
libraries (see Figure1, “Global Call Arch itecture for IP Technology”, on page20 and Figure 2,
“Global Call Architecture for E1/T1 and ISDN Technologies”, on page21 ). FTE is described in the
following topics:
•Feature Transparency and Extension Overview
•Technology-Specific Feature Access
•Technology-Specific User Information

7.4.1 Feature Transparency and Extension Overview

FTE is comprised of a number of Global Call functions. These functions provide the flexibility to
extend the generic Global Call API to access all technology or protocol-specific features unique to
any given network interfaces that were formerly only accessible via their native technology call
control libraries. Thus, all technology-specific features may be accessible from the application
solely via the singular Global Call library interface, thereby alleviating the need to access these call
control libraries directly via additional APIs.