Voice API Programming Guide — June 2005 37
Application Development Guidelines
6.3 Fixed Routing Configuration Restrictions
Flexible routing configuration is the configuration of choice for applications using R4 on DM3.
This documentation assumes that the flexible routing configuration is in use unless otherwise
stated. The following restrictions apply when using fixed routing configuration:
•TDM bus voice resource routing is not supported
•TDM bus fax resource routing restricted
•voice, fax, and Global Call resource/device management restricted
Table3 shows the voice API function restrictions in a fixed routing configuration. For Fax API
restrictions, see the Fax Software Reference. For Global Call API restrictions, see the Global Call
API Programming Guide.
6.4 Additional DM3 Considerations
The following information provides programming guidelines and considerations for developing
voice applications on DM3 boards:
•Call Control Through Global Call API Library
•Multithreading and Multiprocessing
•DM3 Media Loads
•Device Discovery for DM3 and Springware
Table3. API Function Restrictions in a Fixed Routing Configuration
Function Name Notes
dx_close() Limitations: Although dx_open( ) and dx_close( ) are operational on DM3 voice
devices in a fixed routing configuration, their purpose is extremely limited by nature of
the voice resource membership in a DM3 cluster. Instead, you must use the
gc_OpenEx(), gc_GetResourceH( ), and gc _Close( ) functions. See the Global Call
API Library Reference for information on these functions.
dx_getxmitslot() Not supported. The function fails with error code EDX_SH_MISSING, indicating
“Switching Handler is not present”.
dx_listen() Not supported. The function fails with error code EDX_SH_MISSING, indicating
“Switching Handler is not present”.
dx_open() Limitations: Although dx_open( ) and dx_close( ) are operational on DM3 voice
devices in a fixed routing configuration, their purpose is extremely limited by nature of
the voice resource membership in a DM3 cluster. Instead, you must use the
gc_OpenEx(), gc_GetResourceH( ), and gc _Close( ) functions. See the Global Call
API Library Reference for information on these functions.
dx_unlisten() Not supported. The function fails with error code EDX_SH_MISSING, indicating
“Switching Handler is not present”.
nr_scroute() Limitations: Does not support voice, fax, analog network interface devices (LSI), or
MSI devices. Supports DTI devices only.
nr_scunroute() Limitations: Does not support voice, fax, analog network interface devices (LSI), or
MSI devices. Supports DTI devices only.