Device Drivers for ISA and PCIThe software contains two kernel-mode device drivers. The ISA bus device driver, glfxisa.sys, only communicates with the Dialogic CP Fax Series ISA boards; and the PCI bus device driver, glfxpci.sys, only communicates with the Dialogic CP Fax Series PCI boards.
Firmware Download UtilityThe firmware download utility, %gfax%\glfxdldr.exe, is used by the Dispatcher during service startup to download the GDK fax channels. This utility can also be run from the command-line in a console window. For trouble-shooting purposes, the option '-v' can be appended to the utility name to see verbose output when running from a console window. The filename stored for the firmware command can be configured with the Dialogic GDK Configurator utility. Refer to the GDK Installation and Configuration Guide for Windows for more information.
The GDK System Service (the Dispatcher)The GDK System Service (also called the Dispatcher Service) is the operating system dependent interface to both the fax channels and to the API library. This service can be configured from the Control Panel Services Applet (Figure 2).
Figure 2. System Services Control Panel
You can start and stop the GDK System Service from the Control Panel Services Applet, the Start GDK System Service Program in the GDK program group, or from a Command Prompt console window.
The GDK System Service outputs information to the following files:
%GFAX%\gfdNT.log Provides startup and shutdown status information, as well as automatic board detect results and configuration files created.
%GFAX%\gfax.$co Dispatcher "stdout" output. This file is kept open until the Dispatcher exits.
GDK Dispatcher as a Windows System ServiceThere are two processing models: batch processing mode and interactive processing mode. The Dispatcher acts as a fax scheduler in the batch processing mode, finding an available line on any GDK port in the chassis and sending records to the CP Fax board for transmission.
In the interactive processing model, the Dispatcher is the intermediary between the application and the GDK ports. The application is the fax scheduler. It can be programmed to NOT post the completed queue record to the queue file.
The Dispatcher supplies queue records to the firmware. It also can reserve buffer space in RAM for these records to improve system performance. The number of record buffers in a system is configured by the BUFFERS command. The recommended buffer number is two per fax channel, and each record requires 516 bytes.
The QUEUET command determines the time in seconds that the Dispatcher scans the Pending List for new jobs. When the QUEUET timer expires, the Dispatcher starts at the beginning of the Pending List. It then loads and marks "BUSY" as many queue records that are ready for transmission as it has buffers available.
When the record is passed onto the channel, an additional bit is set indicating that the record is off host. When the system sees a record with this bit setting, it does not disturb the record while it is in a buffer or being processed by the firmware. Several records can be marked BUSY even when there is only one fax channel in the system.
Although the original record may be undisturbed in the Queue File, a record marked "BUSY" indicates that a copy of the original is in the record buffer of the Dispatcher or is held by the firmware. The Dispatcher overwrites the original record with updated information when the transaction completes.
Once a remote site confirms a transmission, the Dispatcher sends a confirmation to the Queue file. If a transmission fails, the dispatcher notifies the Queue file, which records the appropriate error message for the failed transaction.
Network Drive AccessThe GDK System Service must be configured to provide access to network drives using drive letter notation (i.e., "p:\public\fax\received\..."). These network drives can be on either Novell or Microsoft servers. For the network drive access to work, the Dispatcher has to be logged into the server where files are located (for sending), and where they will be located (for receiving). This task must be performed after the installation completes. Follow these steps to log the Dispatcher into the server:
The GDK System Service
The GDK Service depends on the successful start of the device driver service and, in certain configurations, the Dialogic service. The GDK System Service configures the fax channel and the GDK system using the information stored in the registry.
GDK Service Dependencies
The GDK will configure the GDK System Service dependencies based on the CP Fax Series hardware detected in the system. The GDK System Service depends on:
The hardware driver service dependencies are required for communication with the CP Fax Series hardware. The Dialogic service dependency is required for an SCbus-system configuration.
About the FirmwareThe firmware is the on-board software that manages the fax transactions and image conversions for each fax channel. The firmware drives the GDK system, telling the GDK System Service when it is ready for more work and when it needs to be serviced. The firmware is downloaded on to each fax channel during GDK system startup.
About the Queue FileThe Queue File operates as the database for the Fax subsystem in the batch processing mode. It stores the fax transmission(s) until the Dispatcher requests it. The Queue File stores future transactions as well as results of past transactions. Transmission statistics regarding each completed transaction are stored in the queue record. For more information about the Queue file, see Chapter 4.
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