Networking the Small Office
As the old saying goes, many hands make light work, when those hands can share information and resources, the benefits – and savings -- are plentiful. Whether it is to share access to files, printers or networked software resources like an intranet server, group calendar or other client/server application, having computers networked together makes it easier to get one’s work backed up and keep track of the big picture.
Back in the bad old days, networking a group of PCs was both expensive and problematic. DOS lacked built-in networking functionality, and so did versions of Windows prior to the release of Windows for Workgroups. Fortunately, networking is now ubiquitous, with support built into Windows, Mac OS, Linux, OS/2 Warp, and practically everything else. Better still, it is a relatively simple matter to interconnect these different operating systems and share data freely among them. Here’s how.
First of all, you need to ensure that each computer has a network card – and that you know what kind it is and where the drivers can be found. These days, most people use the Ethernet standard. There are several Ethernet variants available, delivering throughput speeds ranging from 10 megabits per second to 1000 mbps or more. For PC or Macintosh computers, so-called Gigabit Ethernet cards can be obtained for less than $100, and so-called Fast Ethernet (100 Mbps) are available for less than $20. And then there's the older still 10 mbps 10baseT standard, which is also supported by most (but not all) newer Ethernet cards.
There are, as you can imagine, many brands of Ethernet cards. These days, cards based on the Realtek chipset seem to be the most common. D-Link is another widely available, low-cost brand from which we've had good results.
A few years ago, network interface cards ("NICs") said to be "NE2000 compatible" were the most common. It’s no longer important that the cards you get conform to this standard, but make sure the cards you get are supported by the operating system(s) you plan to run. Ethernet and Fast Ethernet cards are available in ISA or PCI varieties, as are PCMCIA cards suitable for use with portable PCs. There are even USB-connected devices, although the compatibility tends to suffer.
Historical background: What's a BNC connector?
A now-obscure version of Ethernet connection uses so-called "thinnet" (coaxial) type cable. This is now essentially obsolete, but is undoubtedly still in use by many small groups of users who don’t need to conform to an existing network. This thinnet Ethernet cabling is technically known as 10base2 and is colloquially known by the name given to its connector: BNC. The jury is still out on whether this stands for "barrel nut connector," or the fact that it was referred to as a "Bayonet" connector by its developers Neil and Concelman. Other sources define it as possibly standing for British National Connector, Bayonet Navy Connector (maybe used on pier-to-pier networks?) or even Baby N-Connector. Whatever its origin, this probably won't be showing up on a trivia quiz anytime soon.
It offered two main advantages: the cabling was cheap, and you could connect any number of machines together. The main thing you need to know about this type of configuration is the absolute essential requirement for a "terminator" at each end of the network. Simply put, you have to use "T" shaped connectors, with a terminating cap (its actually a 50-ohm resistor) on one end of the "T" at each end of the network chain. You must also avoid any "stubs" -- the "T" connectors must be attached directly to the Ethernet cards. If you try to simply plug a coaxial thinnet cable from one card into the other, it doesn’t work. Remember: the terminators are not optional!
The main drawback with this kind of network is the chaos that ensues when any segment of the cable breaks or is disconnected: the whole network goes down! Obviously, the larger the network, the less sense it makes to try to build it with thinnet cable. To build a network where each machine can be connected or disconnected at will, 10/100baseT, sometimes referred to as UTP (unshielded twisted pair), is your best bet. And yes, there are cards that have both BNC and 10baseT connectors.
If you have to connect to a network that currently uses coaxial cable, you have two choices. You can continue to use coaxial cable and thinnet cards, or get a hub with BNC and 10/100baseT ports, connect the BNC segment of the network to it, and grow the rest of the network using 10/100baseT (or Gigabit Ethernet, if you're really going for the gusto) technology.
BNC, or "thin Ethernet" networks
If you choose to get an Ethernet card with a BNC connector, you have the advantage of being able to connect more than two computers without requiring a hub, but the low cable network card hardware costs are definitely offset by the person-hour costs of lost time when the network goes down.
And, most network administrators will attest, BNC networks are more trouble to maintain and troubleshoot than ones based on 10baseT. Thus, many network administrators tend to prefer the simplicity of 10baseT configurations.
10/100baseT
Basically, a 10baseT connector (called an RJ-45 jack) looks like an oversized modular phone jack. Like phone cable, 10baseT cabling is of the twisted pair variety, which is both easy to wire an office with, and inexpensive. Two 10baseT Ethernet-equipped computers can be connected with a special "crossover" type of twisted pair cable, but to connect more than two computers via 10baseT, you’ll need a small junction box known as a hub.
A hub typically looks like a small box with several connectors on it -- perhaps with a few status lights for good measure. Older hubs often had one BNC connector (a cylindrical connector for use with coaxial cabling) and several 10baseT ports. These days, most hubs support only 10/100baseT, although a growing number of routers (essentially a smart hub with a built-in firewall) also provide wireless capabilities as well. You should be able to find a no-frills hub supporting several users for less than $50. A small workgroup needs only to plug each computer’s 10baseT cable into a port on the hub, run the networking setup for Windows 95 or NT (etc.), and you’re on the network!
Sometimes, a card with both 10/100baseT and BNC is the right solution. If, for example, your business has grown to the point where BNC no longer makes sense (we’re inclined to view anything more than a dozen machines as a BNC network problem just waiting to happen), you can attach these machines to a 10baseT network that will be able to grow and evolve gracefully.
It is worth mentioning that Fast Ethernet and the nascent Gigabit Ethernet use twisted pair type cable. Thus, BNC is growing less common, due to relatively high maintenance and troubleshooting costs.
First things First
First, though, you have to get those cards into the computers!
In most cases, PCI cards will auto-configure via "plug and play;" for ISA-based PCs, cards usually need to be manually configured and, despite the advances made with Windows 95, devices connected to the ISA bus simply aren’t especially good at autoconfiguring. Expect IRQ and memory address problems if you go with an ISA-based card.
Some people software-configurable cards; others prefer cards with jumpers or DIP switches. Some cards can be configured via either method – ask your office expert what he or she recommends. It’s handy to find one brand that works and stick with it. If at all possible, go with a PCI card. You’ll end up with more hair.
In the event you need to reconfigure things down the road, chances are good someone else will have the driver diskette handy and/or know where to download it.
Should you be networking?
Do you:
For more information, see the networking FAQ at: www.tweak3d.net/articles/network/
Final Thoughts
For further reading:
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