|Microsoft Windows printing architecture causes image decompression and
rendering to occur on the client PC. The raw data is sent to the local printer driver on
the client PC and transmitted over the network. This graph shows the number of bytes
transmitted over the network for a 1 to seven single-page black and white TIFF files. The
red plot shows how much data is transmitted using the default Windows printing subsystem.
The blue plot shows how much data is transmitted using the NED NT Print Service. The size
of each original file is about 50kb. Color image files can be much larger than this. The
kb transferred using the NED NT Print Service software is not affected by the size of the
image files, since only the file names and printing instructions are transmitted.
The need for extra memory and disk space on client PCs is eliminated, since all image rendering and printing is performed on the server. This allows low-end PCs running any version of Windows from 3.1 to Windows NT to offload all printing operations to the server. Client ActiveX controls are included for 16 and 32-bit applications.
Client applications also have the option, by using the ActiveX control, to send compressed files from the client to the server. This eliminates image processing on the client, reduces network load, and allows images that cannot be directly accessed by the server to be printed.
|This graph shows the time required to transmit from 1 to 7 pages over an
ethernet network running at 10 megabits/sec. The nominal transmission rate over the
network is 400kb per second for an 802.3 network (ethernet) and 600kb per second for an
802.5 network (Token Ring). The red plot shows the number of seconds required using the
standard Windows printing subsystem. The blue plot shows the number of seconds required
using the NED NT Print Service.
These times are in addition to the time required at the client PC to decompress and render images to the printer driver. Using standard printing (without using the NED NT Print Service), decompression and rendering of the image can take from a few seconds to several minutes per page. During this time, the user's PC is typically sluggish and unresponsive. Using the NED NT Print Service, the time required on the client PC to submit the print request is negligible (less than a second). The user's PC returns to a usable state instantly.
The NED NT Print Service offers two very significant performance improvements. The most significant is the elimination of work required by the client PC to render pages to the virtual printer device. The second improvement is dramatic reduction of network traffic. Combined, these enhancements solve the problem of poor image printing performance in common client-server systems.
Another benefit of the NED NT Print Service is page layout. This feature is normally provided by the vendor of the printer. The NED NT Print Service can render multiple images to a single sheet of paper in any configuration specified by the client application. This allows you to choose printers without layout capability and yet be able to render multiple images to each printed page.The NED NT Print Service is able to render multi-image layouts to any Windows-compatible printer.
|Your document imaging system can be configured to offload image printing traffic by connecting the document archive (optical disk, CD ROM, RAID, etc.) directly to the NT Server through an appropriate connection (SCSI for example), or by attaching the archive and Print Server to a subnet. This allows client workstations to retrieve documents over the network for viewing, while allowing print operations to be handled directly by the server.|