Despite the virtual, micro-sized nature of most computerized phenomena these
days, certain physical realities still limit the fundamentals of computing. One
place where physical limitations come to the fore is in peer-to-peer networks,
such as are most frequently found in small to medium-sized offices and in some
homes. On the other hand, the limitations of peer-to-peer networks --
communities of up to 20 linked computers -- are far outweighed by the freedoms
they provide.
What's the difference between peer-to-peer networks and other kinds? The main
alternative to peer-based networks are server-based ones. Server-based networks
consist of groups of PCs connected via a central computer (the server) that
ordinarily performs such tasks as the backing-up of files, the installation of
software, and other maintenance-oriented functions. The server usually has more
than one hard drive, and if one of these fails, the system continues to
function. However, if all the server's hard drives go on the blink, then each
member of the network feels the effects. If you're working on a computer whose
server crashes, you won't be able to access any files that are shared among that
network, or use any printers or other peripherals that are connected to the
network -- basically, you'll be out of luck.
By contrast, peer-based networks are immune to crashes that affect the whole
office and can ruin an entire day. While PCs in peer-to-peer networks are able
to share files and printers and other equipment, they do not rely on each other
-- or any other central device -- to continue operating. If one crashes, the
others continue humming along. So what are the limitations of peer-based
systems, and what are their component parts?
The small size of these networks means that they must be contained within a
relatively small radius of physical space. No member of the network can be
located more than 500 metres away from the network's central joint, called the
hub. Because peer-to-peer networks are not connected through a server,
individual members must do a bit more work to keep their files safe and
backed-up. And because communication among member PCs is not monitored by a
server, machines can become bogged down with activity (for instance, when you're
working on a certain file and someone else tries to access another file on your
computer). This can cause both computers to slow down as they deal with a double
load of functions simultaneously.
Establishing peer-to-peer networks is a fairly simple exercise. The first
installation to be made involves a NIC (network interface card), which is a
circuit that you slip into a particular slot (the peripheral component
interconnect, to be exact) on your computer's motherboard. The NIC translates
data exchanged between computers on the network. Upon installing the NIC, your
computer acquires an IP (internet protocol) address that identifies your PC to
the network. The actual job of connecting your machine to its counterparts on
the network is effected by an ethernet cord. The ethernet cord attaches to your
NIC and then travels to the hub, a central unit that routes signals among the
network.
Peer-based systems can be set up in one of two ways. They can either be
connected via a hub, or each computer on the network can be connected to another
computer, in a kind of ring formation. The first type of structure is referred
to as a star formation. It affords greater reliability, since the breakdown of
one computer does not affect the operation of other network members. If the hub
itself breaks down, however, the whole system is obviously affected. The
alternative, a ring formation, is cheaper but riskier, in that the crash of one
computer usually entails the disruption of the whole system.
With the advent of phone line connections, however, the star-and-ring days
may be drawing to a close. Phone lines offer sufficient bandwidth for
simultaneous telephone connections and computer network connections. They're
also easier to install, the process being comparable to plugging in your
telephone. Either way, anyone with more than one computer in their life should
consider hooking them up and letting them talk to each other. It wipes out the
need for floppy disks as a transferal method, and it keeps the PCs from getting
lonely.