Thursday, March 27, 2008

Upgrading from 10BASE-2 or 10BASE-T

Twisted-pair wiring pretty much replaced 10BASE-2 many years ago and was, for a long time, the networking solution of choice. Hubs allowed for centralization of wiring and switches helped localize errors due to faulty cables or network adapter cards.

100BASE-T and gigabit Ethernet solutions are now the de facto standards for creating a new network. If you're creating a network from scratch, it's best to start with the latest and greatest if your budget allows.

Like 10BASE-2 networks, you should ask yourself why you would even want to operate a 10BASE-T network. If you already have one in place, continuing to add new hubs, switches, and routers may make sense, provided this limited bandwidth (10Mbps) can satisfy the demands of your users/ applications. However, 100BASE-T (also known as Fast Ethernet) has been around for more than 5 years, and is now the most widely used version of Ethernet between the wiring closet and the user desktop.

If you're going to swallow the expense of pulling new cabling to replace older coaxial cabling, there's no reason to go to 10BASE-T today. Category 5 (and above) cabling can handle both, and almost every network adapter card produced today can operate at 10Mbps as well as 100Mbps. After you've upgraded the cable plant, you might as well go for the added bandwidth of 100Mbps instead.

Hardware and Software Factors to Consider for 10BASE-2, 10BASE-T, and 100BASE-T

Obviously, it's the hardware that you'll have to replace when making this kind of upgrade. Network protocols, such as TCP/IP, don't care what the underlying physical network is made up of as long as they can get data segments from one place to another. However, you might still be using older software, and if so, you might want to consider upgrading it in addition to the hardware when you plan for this kind of upgrade. Novell's NetWare has basically lost the LAN environment to Unix and Windows NT/2000 and Windows 2003 servers, much less the

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Windows XP client, and even the most recent versions of NetWare can use IP. For NetWare 6.X, IP is the main protocol, given the emphasis that Novell now puts on Internet access. For the network that you use, whether it be a built-in technology as with Windows or Unix/Linux or an add-on product such as NetWare, the IP protocol remains an underlying factor.

For a historical overview, 10BASE-2 and 10BASE-T have more differences than just the type of cables they use. Although both of them use the same messaging technique (CSMA/CD), their topologies are basically different: 10BASE-2 uses a bus topology, whereas 10BASE-T (and 100BASE-T) installations use a star topology, implemented by a switch, although you might find an older hub still being used. The distances that can be covered by cable segments are also different. The network adapters transmit signals at different speeds. When preparing for an upgrade, check your network inventory to determine which parts of the hardware you'll have to upgrade in addition to the cabling. The major considerations that need to be researched when upgrading from 10BASE-2 to a twisted-pair network are as follows:

For example, if you're using a multiport repeater, replacing it with a more functional hub or switch seemed a natural thing to do a few years ago. However, remember that the topology rules for 10BASE2 and 10BASE-T networks specify different maximum cable segment lengths, so you might have to relocate wiring closets or make other accommodations if your current distances are too long:

Today, however, using switching technology to replace hubs is about the only option you have today. As stated earlier, you'll find it difficult, if not impossible, to find a hub on the market today. They are legacy devices. If you're going to upgrade your network, consider a switch to be a hub replacement. That doesn't mean you need to discard hubs in small segments of your LAN if you already have them. Indeed, if you connect a few computers that have minimal bandwidth requirements to your LAN, there's really no need to replace a hub with a switch. It all depends on how your users make use of the network. If no one is complaining with a hub connection (which you'll most likely have connected to a switch upstream), don't worry about replacing it. Today it's usually the applications that drive the need for additional network bandwidth. If it's working now and no one is complaining, don't change it.

The main consideration here is the topology requirements used for earlier Ethernet networks. If the cable doesn't provide the distance or bandwidth requirements you need today, you'll have to replace the cabling to accommodate modern networks. In a small LAN environment, this usually isn't the case. In a larger environment, you might have to replace cabling to reach the distances you need, yet still provide the same bandwidth that older equipment (such as hubs) can give to users.

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