Connecting the print server
- Blog of the company "NBZ Computers"
- Tutorial
Today we will test D-Link print servers connected to an OKI printer.
Users often face the question of connecting several printers to one local network. This is essential for organization. normal operation in offices. In addition, print servers are extremely useful for home use. When the printer is connected to one computer, there is a risk that its performance will be reduced. In addition, if the computer fails, printing will stop. The print server will allow you to connect to the printer from other devices.
Certainly, optimal solution V in this case will use the original OKI print server, which is network card, built into the printer and working directly with the system bus. This solution allows you to obtain a completely transparent connection between the computer and the printer via the network, since it provides control of the printer through the web interface of the network card without restrictions on functionality, and the network parameters are configured through the printer control panel. In addition, when using a network connection, it is possible to use such software products, like PrintSuperVision and, even more interesting, PrintControl.
And everything would have been fine if not for the crisis. It is well known that the original network cards, which are additionally equipped with printers - quite expensive devices. So I’m thinking about a more affordable, and also a little more flexible option - an external print server from another manufacturer. 
And so we decided to test several inexpensive and very popular D-Link print servers with OKI B400 series printers.
OKI selected the B410d printer as a test subject. This model is equipped with an IEEE-1284 parallel port and a HiSpeed USB2.0 port. We connected the compact print server DP-G310 to the printer via a USB cable, which combines the functions of wired and wireless communication. The tiny box, slightly larger in size than a smartphone, is equipped with 3 connectors: Ethernet (operating speed up to 100 Mbit/s), USB2.0 and a power connector. In addition, a screw-on wireless antenna is nestled between the network and USB connectors.
First test - working via a wired network with OKI
By connecting the box to a wired Ethernet networks, we launched the management utility, which found the print server on the network and allowed us to configure its IP address. 
It was most convenient to do further configuration through the print server’s web interface, which is what we did. 
Here, as you can see, the basic settings of the network connection are given (the address was obtained from the DHCP automatic addressing server) and you can see the status of the printer connected via USB port(in this case it is in ready mode).
Next, we configure the wireless communication parameters: specify the type (infrastructure) and launch the review. 
And voila - we can print on a printer via a radio channel! Another tab gives quite significant information about the nature of the printer that is supported by this print server: 
Only printers that can print directly from DOS can be connected here, that is, if we are talking about laser printers, then these must be printers that support PCL5/PCL6 system commands. As is known from the performance characteristics of the B400 series printers, these devices are just that. In addition, such functions are supported by other economical printers, For example:
B411d
B431d
Test 2 with multi-printer server
Now let's try something more powerful. We were offered the DPR-1061 model for testing - a universal print server through which you can connect even 3 printers at the same time! 
Print server D-Link DPR-1061, capable of serving up to 3 printers simultaneously 
Print server D-Link DPR-1061: one is used to connect printers parallel port and 2 USB2.0 ports
By connecting the device to the local network and accessing it using the default IP address specified in the instructions with a browser, we can see the internal website. The first thing you need to do is install network printers. And here the installation process is solved quite interestingly: 
Setup Wizard network printer offers to launch a small program: it is stored directly in the memory of the print server and, after loading from there, can be immediately launched (do not forget about the necessary rights to install the printer and that you need to allow the launch of the program downloaded from the website). With its help it is very easy to detect printers connected to the device and install their drivers: 
After installing the printer driver, in its properties in the Ports tab you can see that work in progress via a standard TCP/IP port, which is called usb1, usb2 or lpt depending on which port the printer is connected to. 
However, the names for the ports can be changed in the same place in the Setup section of the internal website: 
From the Maintenance section of the internal website, after installing the printer, you can verify its functionality by printing a demo page (using a standard Windows test page): 
That's it, you can print! Again, no miracle happened with the GDI printer, but the B400 series PCL printers worked successfully both via USB and via a parallel port.
Test results
In general, this is a fairly positive, although quite expected, result: honest print servers work transparently and reliably with honest printers. So those who are looking for a reliably working solution for connecting a printer to a network can be strongly advised to pay attention to OKI printers in combination with D-Link print servers.
Sergey Lebedev training manager and technical support OKI dealers
Introduction
when is the union personal computers The Internet was not yet a ubiquitous phenomenon; anyone who wanted to have a hard copy of a document had to have a printer connected directly to the computer. With the proliferation of laser printers, providing a separate printer for each user has become too expensive.
The first way to share printers was to use switches that allowed you to manually or automatically connect a printer to multiple computers. However, this resulted in the need for long printer cables, as well as the need to coordinate the submission of print jobs.
Server-based network operating systems such as Novell NetWare made it possible to share printers among a significant number of users. When printing, the network software intercepts the characters that should have gone to the printer port and sends them to a queue located on the file server's hard drive. The file server selects jobs from the queue and sends them to a printer attached to either its parallel port, or to the parallel port of one of the workstations. This solution allows you to significantly expand the range of users sending jobs to the printer, and avoids the need to coordinate job submissions, since they are simply sent to the printer when it is ready. In addition, as a result of this work, administration is simplified. However, this method is not without its drawbacks. Connecting printers directly to the server's parallel ports increases the load on the server and limits the location of the printers: they must be located several meters from the server. In addition, the number of server ports is limited, which does not allow adding one or two more printers. Attaching a printer to one of the workstations somewhat alleviates the fate of the server and eliminates the rigid connection of the printer to it, which can now be installed in almost any convenient place. However, at the same time work station The device to which the printer is connected is subject to significant external load and its operation may slow down significantly. This is especially noticeable in peer-to-peer networks with operating systems Windows 95/98.
Therefore, devices called print servers appeared and gave the printer a new quality. Typically, a print server is a small box that has connectors for connecting to a computer network, a printer, and a power source. The number of ports for connecting printers can vary from one to three. Some models also have serial port for connecting a printer via RS-232 interface. The operating mode and the presence of supply voltage are indicated by LEDs. Once connected via a print server, the printer becomes an independent shared device. It can be located in any place convenient for users.
Modern print servers, as a rule, provide operation over all existing network protocols, including IPX/SPX, TCP/IP, NetBIOS, NetBEUI, with all network operating systems, such as Windows 95/98/NT, Novell NetWare, OS/2 and UNIX-like OS. The exception is specialized print servers designed for printing only from office applications and designed to work with Windows 95/98/NT/2000.
To ensure proper setup, the print server must first be configured before installation. For this purpose, one or more utilities are included in the package. In recent years, it has become common to include a Web server in the print server, which allows you to perform the necessary manipulations using a standard browser.
Also, a few years ago, print servers appeared that were capable of operating in auto-negotiation mode 10/100 Mbit/s (which, in principle, is not significant, since the exchange speed of 10 Mbit/s exceeds the capabilities of any printer) and having parallel ports, operating according to the ANSI 1284 standard. As for the presence of several parallel ports, this provides the opportunity for expansion in the future, since the difference in price for single- and multi-port models is approximately $20 per additional port, while the price of the entire print server can amount to 100 dollars or more.
Modern print servers are, as a rule, multi-protocol devices that allow you to turn any printer into a network one. Contrary to its name, a printer combined with a device called a print server is a network printer, not a print server. The fact is that a full-fledged print server not only outputs print jobs, but also temporarily stores them on the hard drive (spooling) and organizes printing in the order they were received (queuing). None of the tested print servers are capable of performing storage and queuing functions, and should not, given the cost of these devices.
The main protocols used in modern local area networks are TCP/IP and NetBEUI, used in networks running Windows NT/2000 and Windows 95/98, respectively. Less common is IPX/SPX, inherited from Novell NetWare. AppleTalk in Russia is most likely an archaic rarity. Most print servers support all of these protocols, although the trend towards IPX/SPX and AppleTalk support is becoming more noticeable.
There are two ways to organize printing on a network using hardware print servers: peer-to-peer and with a dedicated computer that performs spooling and queuing (and, in essence, is a print server).
The first method is somewhat more labor-intensive, as it requires a complete procedure for installing a network printer on each computer. However, it allows you to connect and use the print server exactly as intended. At the same time, each of client computers itself is responsible for organizing the queue and transmitting data to the printer, and the data is transmitted over the network only once.
The second method is when the print server is installed on one of the computers as a local printer, and on the rest - as a printer on remote computer. This method is much simpler to implement, but increases the load both on the computer to which the print server is directly connected, and on the network, since all print jobs are transmitted twice: the first time - to the computer acting as the print server, and in the second - when jobs from the queue are actually transferred to the printer.
Quality criteria
It is theoretically justified and practically proven that even when working with a 10 Mbit/s network, the print server cannot be a bottleneck. The bottleneck is most often found in a printer that is not capable of receiving and processing data at a speed of 10 Mbps (1.25 MB/s, which corresponds to approximately 312.5 pages per second when printing text or 37.5 pages per minute when printing print raster graphics even with a resolution of 600 dpi). The bottleneck may also be in the network OS. Therefore, performance measurements were not carried out and its assessment was purely functional. It involved installing a print server on a peer-to-peer network using NetBIOS and TCP/IP protocols, as well as installing it on one computer and using it as a print server using the same protocols. After installation, a Windows test page was printed. Windows 2000 was installed on all computers on the network, a domain was organized, and a DHCP server was running.
results
Axis 5600+
This three-port print server comes in a sleek, blue-gray plastic casing. The case does not provide wall mounting, so the print server can only be placed on a horizontal surface, such as a table or shelf.
On the front beveled wall there are two LED indicator. The first one - Power - lights up when power is supplied from network adapter. If it blinks, there is a problem with the print server or network adapter. The second - Network - lights up during data exchange over the network.
On the right side wall there is a Test button and an RJ-45 socket for connecting to a local network. Pressing this button once will print a test page containing brief information about the print server. Pressing twice provides a detailed multi-page printout. On the left side wall there is a nine-pin connector for connecting the printer via the RS-232 serial interface. The rear wall is almost entirely occupied by two 25-pin DB-25 sockets for connecting printers via a parallel interface.
The Axis 5600+ print server is a universal device capable of operating on networks running Windows 95/98/Me/2000/XP, UNIX, NetWare, OS/2 and Macintosh. For all these operating systems there are programs for installing and managing the print server.
In operating rooms Windows systems 95/98/NT/2000, Windows 3.1/WfW, NetWare Pure IP, OS/2 using the TCP/IP protocol can be used proprietary utilities AXIS Print System and AXIS ThinWizard. You can also use Web Browser, FTP, telnet, SNMP, HP Web JetAdmin for configuration.
When operating a network running Windows 95/98/NT/2000, Windows 3.1/WfW, OS/2 using the NetBIOS/NetBEUI protocol, configuration and printing are performed using the AXIS NetPilot and AXIS IP JumpStarter utilities.
Interestingly, the print server was unable to print diagnostics on the Samsung ML-1210 printer. But with the HP LaserJet 1100 printer everything turned out great.
CNet CNP410
This print server is designed to be installed directly onto the printer connector. When connecting, the built-in N-Way feature automatically detects the highest possible transmission speed and then automatically sets the port to operate at that speed. Three LED indicators - Power, Status and Flow/Link - make it possible to monitor power status, communication channel load and device status in real time. To configure the print server, use the PSAdmin utility, which allows you to configure operating parameters for all network protocols, NetBIOS, TCP/IP and IPX/SPX. The print server also has built-in flash memory, making device upgrades quick and easy.
The CNP410's small size allows users to connect the printer anywhere on a network running one or more major operating systems.
The CNP410 supports multiple protocols, allowing simultaneous printing from NetWare, Windows 95/98 NT or UNIX systems.
DISTINCTIVE FEATURES:
- Upgradeable via software
- Easy-to-use print server management software for Windows
- Automatic self-test when power is turned on
- Support remote control By SNMP protocol, control via Web from a browser and DHCP
- Availability of built-in high-speed microprocessor
- Availability of flash memory
- Built-in SRAM and EPROM
CNet CNP430
The CNP430 has three parallel ports for printers and one Ethernet/Fast Ethernet port for connecting to local computer network. The built-in high-speed microprocessor allows for fast and reliable data transfer. N-Way instantly detects the fastest possible connection and then automatically sets the parallel port to operate at that speed. The print server has three LED indicators that allow you to assess the status of the device and the congestion of the communication channel in real time. Two of them are located near the RJ-45 socket and display the presence of power supply, connection to the network and data exchange over the network. On top panel There is a print port activity indicator. The presence of built-in flash memory makes the CNP430 an easily upgradeable and flexible device. To configure the print server, use the PSAdmin utility, which allows you to configure operating parameters for all network protocols, NetBIOS, TCP/IP and IPX/SPX. Note that the print server supports remote management via SNMP, management via a Web browser and DHCP.
This print server is ideal solution for most small, medium and large networks. The CNP430 supports multiple protocols, allowing you to simultaneously print from operating systems such as NetWare, Windows 95/98/NT or UNIX. Being palm-sized, the print server can support up to three printers simultaneously. The CNP430 can be set up, configured and managed from any Windows workstation.
D-Link DP-301P+
The D-Link DP-301P+ is a compact multi-protocol print server with one standard 36-pin connector for direct connection to the printer and one RJ-45 10/100 Mbps port. Supporting multiple protocols and high-speed printer communication, this compact device provides superior performance and flexibility for a variety of applications. This print server allows you to connect to a 10 Mbps or 100 Mbps network via a standard RJ-45 input. Determination of a 10-Mbit/s or 100-Mbit/s connection occurs automatically.
Support for TCP/IP, NetBEUI and AppleTalk protocols makes this print server an ideal choice for... simultaneous use various OS. The parallel port supports the HP PJL (Printer Job Language) protocol for bidirectional communication. This allows the print server to receive information from the printer about its status while printing.
The easy-to-use administrator program PSAdmin, designed for Windows 95/98/NT/2000/XP, allows you to install a print server within a few minutes and quickly configure it.
Support for Web management and Telnet allows the administrator to manage and configure the print server remotely via the Internet or UNIX.
This model differs from the DP-301P+ in that it does not support IPX and does not require an additional protocol on the network to control printing. It is also possible to control the device via the Web interface.
Edimax PS-1101
This print server connects to the printer using standard cable. This solution is becoming less and less common for single-port printers. The presence of three LED indicators allows you to evaluate the operating mode of the device in real time. Two of them indicate the connection speed - 10 Mbit/s, 100 Mbit/s - and blink when information is being exchanged, and the Status indicator indicates the state of the printer port. The design of the device is simple: no rounded corners or beveled walls. The print server is placed in an ascetic metal case light gray-beige color. The RJ-45 connector is on the front wall, and the 25-pin socket for connecting the printer and the power adapter socket are on the back.
The print server is capable of operating via IPX/SPX, TCP/IP and NetBEUI network protocols and supports Windows 95/98/Me/NT/2000, Windows NT/2000 Server. The print server is administered via a Web server and using the SNMP protocol.
Edimax PS-1201
The Edimax PS-1201 is a compact multi-protocol print server with one standard 36-pin connector for direct connection to the printer and one RJ-45 10/100 Mbps port. Next to the network connector is a connector for connecting a network adapter.
The presence of two LED indicators allows you to evaluate the operating mode of the device in real time. One of them - 10/100 Mbit/s - indicates the connection speed and flashes when information is being exchanged, and the Status indicator indicates the status of the printer port.
To manage the print server, use the PrintSir utility, installed from the supplied CD-ROM. It allows you to manage the operation of the print server under the control of all protocols and configure parameters such as IP address, method of obtaining it (manually or via DHCP), name working group and etc.
The print server is capable of operating via IPX/SPX, TCP/IP and NetBEUI network protocols and supports Windows 95/98/Me/NT/2000, Windows NT/2000 Server. The print server is administered via a Web server and via the SNMP protocol
Edimax PS-3101P
This print server has three parallel ports with D-25 connectors for printers and one Ethernet/Fast Ethernet port for connecting to a local area network. It is made in an original two-color plastic case, which has a streamlined shape with rounded corners. There are five LED indicators on the beveled front panel, allowing you to determine the status of the device and its operating mode at any time. Two of them - 10 Mbit LINK/ACT and 100 Mbit LINK/ACT - indicate the speed of the connection to the local network and blink during data transfer. Three more indicators display the status of each of the printer ports. The last one - Power - lights up when there is DC power from the network adapter.
To manage the print server, use the PrintSir utility, installed from the supplied CD-ROM. It allows you to manage the operation of the print server under the control of all protocols and configure parameters such as the IP address, the method of obtaining it (manually or via DHCP), the name of the workgroup, etc.
The print server is capable of operating via IPX/SPX, TCP/IP and NetBEUI network protocols and supports Windows 95/98/Me/NT/2000, Windows NT/2000 Server. The print server is administered via a Web server and using the SNMP protocol. Supported operating modes are NetWare Remote Printer, TCP/IP Remote Printing, UNIX LPR Printing.
Genuis GPS300D II
This miniature print server is designed to be installed directly onto the printer's Centronics connector. On the other side of the case there is a power connector, an RJ-45 socket for connecting to an Ethernet network, and two LED indicators. One of them - Flow/Link - glows green when there is a connection to the local network, the other blinks five times when the power is turned on, and subsequently blinks when exchanging data over the network.
The print server is capable of operating in the following networks: Novell NetWare 3.12, 4.x, 5.x; Microsoft Windows 95/98/Me; Microsoft Windows NT/2000; Apple EtherTalk; UNIX. To be fair, it should be noted that EtherTalk is mentioned only once - in the list of supported operating systems.
IPX/SPX, TCP/IP and NetBEUI protocols are supported.
You can configure the print server using the PSAdmin utility and the embedded Web server. Both methods make it possible to configure all parameters of the print server and control its operation when interacting with various protocols.
Built-in flash memory allows software upgrades. The mini-server supports 10Base-T and 100Base-TX connectivity, providing automatic sensing and two-way communication (IEEE-1284 standard) high performance at 10 and 100 Mbit/s.
The main features of the print server include the following:
- Fully compatible with Novell NetWare, UNIX, Mac, Windows XP/Me/2000/NT/98/95
- Supports peer-to-peer networks
- Supports Windows XP/Me/98/95 OS
- Supports IPX, NetBEUI, TCP/IP and AppleTalk protocols
- Has an easy-to-use configuration program for Windows
- Acts as a print manager in Windows environment
- Supports DHCP client network management and SNMP protocol
- Supports IPP (Internet Printing Protocol)
HardLink HPS-101
Single-port print server designed to operate on a network with a data transfer rate of 10/100 Mbit/s. Has a DB25 printer connector. Comes with drivers for all popular operating systems. The presence of three LED indicators allows you to evaluate the operating mode of the device in real time. Two of them indicate the connection speed - 10 Mbit/s, 100 Mbit/s - and blink when information is being exchanged, and the Status indicator indicates the status of the printer port. The design of the device is simple: no rounded corners or beveled walls. The print server is housed in an ascetic metal case in a light gray-beige color. The RJ-45 connector is on the front wall, and the 25-pin socket for connecting the printer and the power adapter socket are on the back.
The print server supports TCP/IP, IPX, NetBEUI protocols and has drivers for all modern popular operating systems, including Microsoft Windows 95/98/Me/NT/2000, Novell NetWare and UNIX. To manage the print server, use the PrintServer Configuration utility, installed from the supplied CD-ROM. It allows you to manage the operation of the print server under the control of all protocols and configure parameters such as the IP address, the method of obtaining it (manually or via DHCP), the name of the workgroup, etc.
This print server has numerous features that make it a plug-and-play device, such as DHCP server/client, auto-discovery of destination IP address, auto-tuning to the desired network speed, quick installation utilities for Windows and NetWare, easy management through standard window Internet browsing.
The print server is capable of operating via IPX/SPX, TCP/IP and NetBEUI network protocols and supports Windows 95/98/Me/NT/2000, Windows NT/2000 Server. The print server is administered via a Web server and using the SNMP protocol.
HardLink HPS-103P
HardLink HPS-103P - three-port print server. It is made in a rectangular plastic case with rounded corners and a beveled front panel. At the bottom of the case there are places for wall mounting. There are six LED indicators on the panel. There are five LED indicators on the front panel, allowing you to evaluate the status of the device and its operating mode at any time. Two of them - 10 Mbit LINK/ACT and 100 Mbit LINK/ACT - indicate the connection speed to the local network and blink during data transfer. Three more indicators display the status of each of the printer ports. The last one - Power - lights up when there is power DC from the network adapter.
To manage the print server, use the PrintServer Configuration utility, installed from the supplied CD-ROM. It allows you to manage the operation of the print server under the control of all protocols and configure parameters such as the IP address, the method of obtaining it (manually or via DHCP), the name of the workgroup, etc.
It supports TCP/IP, IPX, NetBEUI protocols, and has drivers for all modern popular operating systems, including Microsoft Windows 95/98/Me/NT/2000, Novell NetWare and UNIX.
The HardLink HPS-103P includes numerous features that make it a plug-and-play device, such as DHCP server/client, auto-discovery of destination IP address, auto-tuning to the desired network speed, utilities quick installation for Windows and NetWare, easy control via a standard Internet browser.
The print server is capable of operating via IPX/SPX, TCP/IP and NetBEUI network protocols and supports Windows 95/98/Me/NT/2000, Windows NT/2000 Server. The print server is administered through a Web server, using the SNMP protocol and through the Windows Configuration Utility.
Surecom EP901X
This print server is designed to be installed directly onto the printer connector. When connecting, the built-in N-Way feature automatically detects the highest possible transmission speed and then automatically sets the port to operate at that speed. Three LED indicators - Power, Status and Flow/Link - allow you to monitor power status, communication channel load and device status in real time. To configure the print server, use the PSAdmin utility, which allows you to configure operating parameters for all network protocols - NetBIOS, TCP/IP and IPX/SPX. Print servers also have built-in flash memory, making device upgrades quick and easy.
The EP901X's small size gives users the ability to connect the printer anywhere on a network running one or more major operating systems.
The EP901X supports multiple protocols simultaneously, allowing its users to print simultaneously from NetWare, Windows 95/98/NT and UNIX systems.
Surecom EP903X
The EP903X has three parallel ports for printers and one Ethernet/Fast Ethernet port for connecting to a local area network. Built-in high-speed microprocessor ensures fast and reliable data transfer. N-Way instantly detects the fastest possible connection and then automatically sets the parallel port to operate at that speed. The print server has three LED indicators that allow you to assess the status of the device and the congestion of the communication channel in real time. Two of them are located near the RJ-45 socket and display the presence of power supply, connection to the network and data exchange over the network. The top panel has a print port activity indicator. The presence of built-in flash memory makes the EP903X an easily upgradeable and flexible device. To configure the print server, use the PSAdmin utility, which allows you to configure operating parameters for all network protocols NetBIOS, TCP/IP and IPX/SPX.
This print server is an ideal solution for most small, medium and large networks. The EP903X supports multiple protocols, allowing you to simultaneously print from operating systems such as NetWare, Windows 95/98/NT or UNIX. Being palm-sized, the print server can support up to three printers simultaneously. The EP903X can be set up, configured and managed from any Windows workstation.
Support for TCP/IP, NetBEUI and AppleTalk protocols makes this print server an ideal choice when using different operating systems simultaneously. The parallel port supports the HP PJL protocol for bidirectional communication. This allows the print server to receive information from the printer about its status while printing.
The easy-to-use administrator program PSAdmin, designed for Windows 95/98/NT/2000/XP, allows you to install a print server within a few minutes and configure it.
Support for Web management and Telnet allows the administrator to manage and configure the print server remotely via the Internet or using UNIX. It is also possible to control the device via the Web interface.
Glossary
ANSI 1284 - the standard, released in 1994, describes methods for transmitting data over a parallel interface and relates to the original Centronics port approximately as Pentium processor to 286. It describes high-speed bidirectional data transfer between a computer and peripheral devices at speeds 50 to 100 times higher than LPT port specifications. However, it remains incompatible with legacy devices.
The following compatibility modes are supported:
Compatibility Mode- standard Centronics;
Nibble Mode- 4 bits in parallel on status lines, HP Bi-tronics;
Byte Mode- 8 bits on data lines, sometimes referred to as bidirectional;
EPP(Enhanced Parallel Port - extended parallel port) - used mainly for communication not with printers, but with devices such as CD-ROM, tape drive, MO drives;
ECP(Extended Capability Port - port with extended capabilities) - used mainly for connecting new printers and scanners.
The standard also includes methods and protocols by which, as a result of negotiations, two devices select the most suitable mode.
IPX(Internetwork Packet Exchange) is a network layer protocol designed to deliver data without establishing a connection. Developed based on the IDP (Internetwork Datagram Protocol) protocol from the XNS (Xerox Network Service) suite. Its main functions are data delivery and routing.
IPX/SPX- a generic name for a set of protocols used by Novell NetWare OS. Before the advent of IntraNetWare and NetWare 5, this set was “native” and was required to be installed. It is a compact, low-configuration, routable protocol ideal for local area networks.
NetBEUI(NetBIOS Extended User Interface) - was developed by IBM in 1985. This extension was used on the network Token Ring. Up to 260 devices were allowed in one ring; rings could be combined using bridges.
NetBIOS(Network Basic Input/Output System) - the interface was developed in 1983 by Sytec, Inc. (now Hughes LAN Systems) commissioned by IBM. It included an API (Application Program Interface) that allows applications to be isolated from the network environment, and a number of proprietary network protocols. One network allowed 72 or 80 devices (depending on the physical implementation). Devices on the network are identified by name, the length of which should not exceed 15 characters. Because the this protocol is not routable, versions of its encapsulation in the IPX and TCP/IP protocols have been implemented.
P.J.L.(Printer Job Language) - in addition to the standard PCL (Printer Command Language) allows the printer to perform some additional functions, such as duplex communication via parallel port. The printer can transmit and receive data about the status of indicators and settings on the control panel; if there are several ports, each of them can have its own printer configuration, and data can enter the buffer even if it is offline; Context-sensitive switching allows automatic recognition of the job type (PostScript or PCL).
SPX(Sequenced Packet Exchange) is a transport layer protocol designed for data delivery with connection establishment and guaranteed delivery. Developed based on the Xerox Sequenced Packet Protocol. The main function is guaranteed data delivery. It is to IPX what TCP is to IP.
In companies that have a small to medium-sized local network, a fairly common option for network printing is to use a small local printer that is connected to one of the computers on the network. The main advantage of using this option is cost-effectiveness. However, when implementing this option, printing uses additional resources computer to which the device is connected, which leads to a significant decrease in its performance. Dedicating a separate computer just for network printing is expensive with financial point vision, especially if the required print volume does not exceed the capabilities of the printing device. The solution to this problem may be the use of the so-called print server.
The print server (print server) is small device, connected to the local network (cost from $40), to which they connect one or more printers(the number of connected devices is determined by the type of device). Exists two types of print servers: internal and external. External print servers in most cases they work with any devices, regardless of the manufacturer, and internal exclusively with printers from the print server manufacturer. But regardless of the type of print server, it is “transparent” to operating systems and requires only the correct configuration of parameters for the data transfer protocols used on the network.
Basically, print server models differ in the type and number of ports used to connect printing devices, network speed, dimensions, and spectrum network protocols, which it is able to support and, as a result, the ability to work in a “multi-operational” network (that is, a local network to which PCs with operating systems of various types are connected).
The print server comes complete with proprietary software that allows you to administer the work and has advanced or not advanced diagnostic and configuration tools. Basically, this software allows you to work only with devices from the print server manufacturer.
Depending on the manufacturer and model of the print server There are several options for "behavior" it on the local network. When some models are connected, they are displayed in the network environment as a separate computer with printers connected to it. In this case, to install the printer on a work computer, the usual algorithm used to connect a regular network printer is used. In this case, there is no need to install additional software from the print server developer on the client machine. Administration of the print server is carried out only from the computer on which the configuration software was installed. In another case, to install a printer that was connected to the print server, you need to install and configure client part software. Wherein client program emulates the local port of a printing device on a computer.
Andrey Borzenko
Today, printers directly connected to the network have become traditional office equipment. They provide fast printing and easy installation regardless of location, which is so important for network administrators. However, in organizations with a small and medium-sized local network, the most common option for collaborative network printing remains a personal printer connected to one of the PCs (Fig. 1). The main advantage of this option is cost-effectiveness. However, it should be remembered that this printing method uses the resources of the PC to which the printer is connected, and the computer's performance is significantly reduced. So, with large volumes of network printing, it becomes very difficult to use this PC for its intended purpose. Dedicating one computer only for network printing, as well as purchasing a special network printer, is often unjustified from a financial point of view, especially if the printing volumes do not exceed the capabilities of the printing device used. So-called print servers, or print servers, are designed to help solve this problem.
Print servers are small network devices to which one or more printers can be connected (Fig. 2). They come in two types: external and internal (Fig. 3). The latter are made in the form of a board and, as a rule, can only be used with certain printing devices. The most notable limitation of internal network cards is that a specific printer must support them. This means that if the printer was made before the advent of such devices or if the printer is new, but internal maps it does not support it, you will have to use an external network printing device.
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Rice. 2. Print server for two printers. |
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Rice. 3. External and embedded print servers. |
Additionally, the internal board only serves one printer. External print servers can support multiple printers simultaneously, thereby saving on additional ports. Having a single device handle many printers also reduces configuration needs and resources. For example, one IP address is enough for each printer, while printers with internal board Each person will have to have a separate address.
Often internal network cards have restrictions on the number of supported network protocols and their simultaneous support: it happens that required protocol is not supported or the two protocols cannot operate simultaneously.
An external print server enables transparent, network printer sharing. As well as network computer with a printer connected to it, the external print server has its own network connection, and the printer (or printers) connects directly to the server. In this case, there is no need to spend money on purchasing and maintaining a relatively expensive PC - instead, an inexpensive, small-sized, easy-to-use device is used.
Advantages of external print servers
Print servers are usually recommended to be installed in medium and large networks, where remote control of printing devices is required. Their use is especially effective in cases where there are many printers on the network located on different floors and even in different buildings, and it is necessary to provide the administrator with maximum management capabilities, and the user with maximum convenience for working with them.
Saving money
To print from a computer or file server with a connected printer, you need to have this computer or server, and they are quite expensive. Costs increase significantly if multiple printers needing network access are distributed throughout the office. Even the simplest computer is significantly more expensive than a powerful multi-protocol print server that can support multiple printers simultaneously. In addition, the print server allows you to reduce the time spent on support and service (computer maintenance requires significantly more time).
Main processor offload
Processing print jobs takes up a lot of CPU time on the computer to which the printer is connected. If your PC is also performing other tasks or sharing files, printing can significantly impact its ability to perform other tasks. Printing performance also leaves much to be desired if the computer simultaneously performs several tasks that significantly load the processor.
The reason for the high load on the processor is the so-called software character-by-character I/O mechanism. Its essence is that when the server sends a print job to the printer, a processor interrupt is initiated for each character. In this case, it does not matter which computer is used - an outdated XT-shka or the most fast car based on Pentium 4. The requirements for the server increase significantly if it services several printers.
The print server uses DMA (Direct Memory Access) instead of software character-based I/O. In this case, the processor interrupt is triggered only for entire data packets. This way, the print server not only frees up your computer or file server so it can perform other tasks more efficiently, but also allows you to achieve faster network printing.
Convenient accommodation
When you connect printers to a computer or file server, you don't have to choose a location. And since servers, for example, are usually located in a secure, specially air-conditioned room or closer to the system administrator, they are often inaccessible to most users who have to make long “walks” to pick up documents sent for printing. Network print servers, on the other hand, allow you to place printers anywhere on the network, exactly where they are needed most. Thanks to small size Such devices can be connected directly to the printer or placed in places where they do not interfere with anyone.
Additional job processing
Often in a heterogeneous network environment, print jobs created on different operating systems or networks require additional processing before being sent to a particular printer. For example, many print jobs created on UNIX require "carriage returns" to be inserted at the end of lines, otherwise the printer will print the text in a "ladder" manner. Another standard pre-processing requirement is printing title page for each job so that users can find their documents in the printer's output stack. In many cases, the printer needs to be configured differently for different users.
This feature is often provided on print servers using virtual printer technology, allowing significant savings on the purchase of additional printing devices. In this technology special virtual printers configured directly on the print server. Users submit their jobs to the virtual printer and the jobs are preprocessed according to predefined conditions. For example, one virtual printer can be used to insert carriage returns in jobs from UNIX computers, another can be used to convert ASCII jobs to PostScript for users whose applications do not support this format, and a third can be used to prioritize jobs from users who require provide a certain level of security. In addition, all virtual printers can be configured to print a cover page. The advantage of a print server is that all these virtual printers are located on one server and all users are served by one physical printer.
Control options
It is vital for network administrators to know what is happening on the network. When printing is entrusted to the server, it generates messages about the status of print jobs, the number of pages printed, and notifications about printer problems, such as printer inaccessibility, paper jams, or missing paper. These messages are sent directly to the network administrator via e-mail or are logged in the system log.
In addition, print servers often support SNMP management, allowing full management of standard SNMP applications such as Hewlett-Packard's OpenView, Sun's SunNet Manager, or Castle Rock's SNMPc.
Print server capabilities
Print servers are currently produced by companies such as Axis Communications (http://www.axis.com), Digi International (http://www.digi.com), D-Link Systems (http://www.dlink .com), Hewlett-Packard (http://www.hp.com), Intel (http://www.intel.com), Lantronix (http://www.lantronix.com), Lexmark (http:/ /www.lexmark.com), Microplex Systems (http://www.microplex.com), NetGear (http://www.netgear.com) and others (Fig. 4). These devices are slightly larger in size than a regular video cassette. Each of them has a connector for connecting a power supply, an RJ-45 Ethernet 10/100 Mbit/s socket and several printer ports (parallel and serial). Some devices have built-in hubs. Typically, all print servers can simultaneously handle text printers and PostScript printers. Most printers on the market are compatible with these servers, but there are some that do not work with them. These are low-cost printers, such as the HP DeskJet 700, 820, or 1000. They use Windows 95/98 to perform most image rasterization functions and only function when connected directly to a PC running one of these operating systems.
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Rice. 4. Print server D-Link DP313. |
With built-in Web servers, all print servers can be configured using a browser. New devices usually support IPP (Internet Printing Protocol). Automatic IP address assignment and intuitive printer naming with DHCP and WINS/DNS support simplifies installation and configuration. Each device can perform a test print or display a status printout containing information about its IP address, active protocols, the number of documents in the print queue, the types of printers connected to it, and other information. Some print servers are equipped special button check, when clicked, a diagnostic printout with information is displayed on the printer. In most cases, the print server is able to determine the type of connected printer and the required network protocols. Automatic recognition speed and transmission media eliminates the need to configure these settings during installation.
Typically, each print server comes with a CD-ROM with configuration and management utilities. Because new print servers have an open architecture, they can be updated by downloading new firmware stored in flash memory. This allows print servers to adapt (at least for some time) to ongoing technical changes.
To network servers and client PCs could work with the print server, they must be configured correctly by installing drivers for new network printers on them. There are two main configuration methods: the first involves creating a virtual local printer port (on a PC or server) using software supplied by the print server manufacturer, and the second is using the new IPP protocol (if the client OS supports it). Some print servers have special means, with the help of which an installation disk is created for a new network printer, containing the driver for this printer, as well as information about the IP address of the print server and the password for accessing this printer. You can install the printer driver in another way - using the IPP protocol.
Speed up printing
The printer is the bottleneck in almost any printing configuration. Print servers are capable of delivering speeds much faster than a standard computer parallel port, and in most cases deliver data faster than a typical printer can process it. For example, Microplex print servers are equipped with parallel ports with a throughput of more than 200 thousand characters per second. A standard computer parallel port transmits approximately 30 thousand characters per second.
Here it should be emphasized once again that print servers support most well-known printing devices - from the latest laser to the oldest dot-matrix printers. In addition, any printing languages are supported, such as PostScript, PCL, HP-GL and others. The print server doesn't care what type of data passes through it. It simply forwards the data transparently to the connected printer or printers. The only exception is when special data processing is required, such as conversion from ASCII to PostScript. In this case, the print server looks only at the beginning of the data to determine whether conversion is required.
Generally speaking, to evaluate printing performance, it is necessary to know the bottlenecks of this process. So, when preparing a job for printing word processor takes the time to convert a document from its native format to a printer format such as PCL or PostScript. The conversion process depends on the size of the document and the performance of the word processor when performing this operation; it can be quick or take a fair amount of time. Conversion time also greatly depends on PC performance. The time it takes to transfer a job from the word processor to the print queue is called swap time. It is determined by factors such as performance application program as data moves to the printer port (or print queue), and network performance when transferring print data and queuing it. The time a print job waits to be printed is called wait time. It depends on a number of factors, including the number of jobs in front of it, their size, the speed of the server and how it is used. The print server periodically checks the print queue, if there is one at all, to see if there are jobs to print. If there is such a queue, and the printer is online and ready to accept, then the print server will begin to move the job from the queue to the printer. This process is called unpaging or dequeuing, and the time it takes to move the entire print job to the printer is called unpaging time. Factors that control unpaging time are the speed at which the print server can remove data from the print queue and the speed at which it routes that data to the printer. Another key factor- speed of data reception by the printer.
As practice shows, it is the time when pumping is removed that often has the maximum impact on network system print. In a well-organized network printing system, latency is usually low because the print job is often the only one in the queue. In this case, once the word processor has finished paging, the only thing left for it to do is print, which will take unpaging time depending on the print server.
Print servers serve all jobs on an equal basis using the FIFO principle: First In - First Out, i.e. there are no preferences for individual computers or networks. Each I/O port typically has its own queue, which is processed independently from the queues of other ports. Thus, a print server with four I/O ports (two parallel and two serial) can support four queues, each serving its own printer. The ports support printing simultaneously without the risk of jobs getting mixed up or lost.
At any given time, the print server stores only a few kilobytes of data per I/O port, with the remaining data stored at the job source. There are simply no print servers on the market today that can fully spool print jobs, so the source computer is always involved in job spooling. In most cases, this operation is performed very quickly.
Access control
If the print server is not equipped with security features, then no matter how many security mechanisms are hidden in the network OS, the network administrator receives open system, where there is no way to prevent access by users who do not have sufficient rights. The ability to restrict access to a printer has significant potential benefits. In particular, unauthorized use of a printing device leads to increased maintenance costs and Consumables. If the printer prints unauthorized jobs, then it is not available for urgent business projects that have tight deadlines. The consequences of poor printer usage controls can be more severe if print servers support printers that print checks, accounts payable, and other accounting documents. In many cases, access control can prevent serious negative consequences that could result from unauthorized printing in institutions that handle confidential documents.
In many cases, network administrators organize a centralized queue of print jobs. Users submit jobs to a centralized queue on the file server, which then forwards the jobs to the print server, which in turn forwards the job to the printer. Thanks to this discipline system administrators can centrally manage all user print jobs. This allows you to use network operating system capabilities such as automatic download printer driver when connecting to a queue, while maintaining the performance and location freedom of print servers.
In some situations, sending print jobs to a centralized queue is either impossible or ineffective. An example would be a remote office equipped only with workstations and connected to the headquarters by a slow communication channel. It is often impossible to create a centralized print queue, either because the file servers are overloaded or for other reasons. IN similar situations It makes sense to have workstations print directly to print servers. Print servers support both shared access and direct printing.
Since network OS security features can restrict access only to the file server's print queue, you can use any computer connected to the network to send a print job directly to the print server, bypassing network OS control. A reasonable solution in this case is to equip the print server itself with security measures.
One solution to the problem of unauthorized access is the use of Intel password protection technology. This technology complements the security features found in most network operating systems. A security check is performed whenever a user attempts to print directly to a network printer, bypassing the security features of the network OS. For example, with Intel NetportExpress 10 and 10/100 print servers, administrators can set a password for any connected printer. In an environment with sharing printing, for example when users send print jobs to a queue on Windows server NT, the administrator can configure the NT server settings so that it forwards jobs to the print server with a password. The file server is the only computer that needs to know this password. The administrator controls access to the print queue using normal network OS security features. It should also be noted that in a situation where workstations print directly to a printer, there is no centralized queue of print jobs on the network and the network OS does not control access to the print server. Anyone can use the printer. This technology overcomes this limitation by replacing the security features of a network OS. Only those users who know the corresponding password can print documents to a specific printer from their workstations. If the workstation specifies the wrong password, the print job simply fails, as if the printer were not connected to the network at all. So, if an administrator has three printers connected to the same print server, then any of them (or all at once) can be equipped with a unique password. For example, if monochrome laser and color inkjet printers are connected to the print server, then access to laser printer can be allowed to everyone, and access to color inkjet printer Restrict with a password. Printer passwords can be used to UNIX systems, Linux, Windows NT, Novell and even AS/400.
Today, for most new devices, you can restrict network access to them and to their individual printer ports. This restriction may be necessary, for example, if the printers contain special paper ( various kinds forms, forms, etc.) or if you need to ensure printing only through a file server (running Linux, NetWare or Windows NT). If the print server is configured to allow access only to the file server, then users will not be able to bypass the file server by interacting directly with the print server. Print servers also have the ability to restrict access to their Web interfaces using a password.
Protocol support
In heterogeneous network environments, administrators must maintain multiple various services seals and protocols. Print servers enable multiple network users to print to the same printer using different network protocols. So this is great way reduce the cost of a workplace. Users can use the same printer even if they are on different platforms. Modern servers Printers usually support TCP/IP, IPX, DLC/LCC, AppleTalk/EtherTalk, NetBIOS/NetBEUI, LAT protocols, making them possible to use even in mixed environments. As for printing protocols, they usually include LPD, RSHD, FTPD, direct connection, PSERVER, RPRINTER, LPD, print manager, etc.
With constant growth computer networks The process of managing printing in them also becomes noticeably more complicated. Print servers are designed to solve this problem. And the more “smart” they are, the more functions they begin to take on, the easier it will become for the administrator to solve network problems, and users will be able to work much more efficiently. Online printing has undergone fundamental changes in recent years, and there is no end in sight to this process of change in the foreseeable future. Companies want enterprise-scale remote printing solutions, and network administrators are looking for tools that simplify management and provide greater centralization of printing processes.
In organizations with a small to medium sized local area network, a common option for shared network printing is to use personal printer connected to one of the PCs. The main advantage of this method is its cost-effectiveness. But in the current version, additional resources of this PC are used when printing. At the same time, the performance of such a computer is significantly reduced. Dedicating one PC only for network printing is financially expensive, especially if the printing volumes do not exceed the capabilities of the printing device used. So-called print servers are designed to help solve this problem.
What is a print server?
The print server is a small network device costing from $40, to which one or more (depending on the type of device) printers can be connected. There are two types of print servers: external and internal. The former can work with any printer, regardless of the manufacturer. Internal - only with print server developer printers. In any case, the device is “transparent” to the OS and only requires correct configuration of its parameters for the transport protocols used on the network.
Different models of print servers differ mainly in the number and type of ports for connecting printers to them, network speed (10 or 100 Mbps), size, as well as the range of supported network protocols and, as a consequence, the ability to work in “multi-operation” networks (i.e. i.e. local networks that use PCs running various types of OS).
Each print server comes with a proprietary administration program, with advanced or not very advanced configuration and diagnostic tools. As a rule, such software only works with devices from one manufacturer.
Depending on the model and manufacturer of the print server, there are several possible options for its “behavior” on the network. Some models become visible on the network as separate PCs with printers connected to them. In this case, to install a printing device on a work computer, the usual algorithm for connecting a network printer is used. In this case, you do not have to install any additional software from the print server developer on the client machine. The latter is administered from the PC on which the configuration software is installed. In another case, to install a printer connected to a print server on the user’s PC, it is necessary to install and configure the client part of the included software, which emulates the local printer port on his machine.
