Intra-nets, networks that run within a business location and connect its offices and
departments, are a critical business asset for research, sales, accounting and
administrative activities. Making a LAN work for your company requires your attention to
some serious questions, here are some things to consider:
The role of the network.
How will employees be using the business network internally and externally? If you measure
downtime in terms of dollars lost per minute, then your network demands a design with
both power redundency as well as data rendundency. Sharing information on your network
with the outside world may also require you to protect your internal network (LAN) with
hardware or software otherwise known as a "FIREWALL"
Applications. Many line-of-business applications demand a specific type of network
server, and some will only work with certain makes and models of printers and input
devices. You might think that you’d like to have the economy of networking under
Windows 95 or 98, but the core business application you want to use might be designed
for the business Windows NT 40, windows 2000 or XP operating systems or some version of Unix. You should not
make your decision about any key business applications until you ascertain their
requirements in advance.
Outside connections. Should your employees have Internet access? Should you
establish a private network across the Internet (an intranet, extranet or VPN) for
communications with your suppliers, accountants, shippers, and other business associates?
Do you want to route secure office traffic across the Internet using architectures such
as virtual private networks?
Maintenance. Who will be responsible for maintaining the computers, network,
software, and communications links? Computers and networks don’t take care of themselves.
You need either your own experienced staff or a skilled yet affordable outside consultant.
No matter where you are, it’s difficult to attract and keep people with networking skills,
but the rates for good consultants start at $100 an hour and the jobs always take longer
than seems reasonable. Make sure that you’ve always got someone trained to take over if
your administrator leaves for greener pastures or if you decide to let your consultant(s) go.
Warranty coverage. We believe that buying onsite warranty service for individual
pieces of equipment is a good investment, but the warranty doesn’t cover the interaction
of the equipment as a system. System integration is an art. You’re reading this article,
so be prepared: You might be a candidate to serve as the first line of system integration
and technical support in your business.
Ethernet. Ethernet has come to denote a large package of interoperable computer
connection technologies from many different companies. The most common connection is
called 10Base-T - 10 Mbps signaling over unshielded twisted-pair (UTP) wire. Ethernet
technology called 100Base-T offers the same connection reliability and interoperability,
but 10 times faster.
Every networked computer needs a LAN adapter card, also known as a network interface card
(NIC). If you’re buying new PCs, then you should purchase them with Ethernet connections
already installed. Every major PC manufacturer offers this option. If you aren’t buying
new PCs, then you’ll either have to add NICs to your existing hardware, or you’ll have to
pawn the job off on somebody else, like a consultant.
The so-called 10/100 adapters for PCs are available at prices ranging from about $30 to a
little more than $100. The higher priced adapters typically have some special capabilities,
such as internal management and reporting, as well as a PCI interface. Older-technology
ISA adapters cost less, but are often much harder to install because they lack
plug-and-play support. As long as the system has an open PCI expansion slot, you should
order a PCI-based NIC.
The cable needed to connect networked computers can present a significant challenge. If
neatness counts in your office, you’ll pay a lot more for cabling that’s long enough to
hide. You can buy your own cables with connectors attached and snake them behind desks
and around doorways if you want to do your own wiring. You should specify Category 5
cables and connectors. A 100-foot cable will cost about $40, and a 25-foot cable will
still be about $16 because most of the cost is in the connectors.
If you want a professional network-cable installation, make sure you use a contractor
with experience in installing network cables and check references. One reversed wire pair
or one bad connector can lead to intermittent, troublesome, and expensive problems. Tell
the contractor that you want a certified Category 5 installation. Once the installation
is complete, you should receive a printout showing the measured performance results for
each cable. Costs for professional wiring installations vary widely, but start with $100
per connection as a very rough estimate.
The right hub. The final basic piece of infrastructural equipment you’ll need is a
wiring hub. The hub serves as a central connecting point for each node on the network.
Its primary job is to prevent trouble; if one node has a shorted wire or sends bad data
packets, the hub can shut it off from the rest of the network and prevent a disruption.
You can expect to pay about $10 per port for a 10 Mbps hub and $50 per port or more for
a 100 Mbps hub. Don’t forget that the hub is so critical to network operation that it
needs backup power protection from a UPS just as the server and other critical nodes on
your network do.
Serious Business. If your network produces revenue by the minute, you’ll want to
invest in some specific capabilities to protect that revenue stream. Line-of-business
networks need three things: compatibility, reliability, and scalability. Compatibility
specifically means, “Does your application software work with your network operating
system and hardware?” That’s a question for the company providing your specific
business application. Its recommendations will probably drive the brand of network
operating system you use and hardware details such as the size of the server’s disk drives.
Though many new applications use Windows clients and run on a Windows NT server, there
are many serious business programs that might not like Windows, wanting a server running
a specific brand and version of NetWare or Unix instead.
You gain reliability through hardware redundancy. In server hardware, reliability comes
from using multiple CPUs, error-control code (ECC) memory, and redundant disk drives.
Fortunately, these same features also give you the power to scale up as your business
grows. Installing a redundant array of disk drives (known as RAID) in a server can double
its price, but RAID, especially a technique called RAID 5, offers superb reliability.
Other alternatives, such as two spanneddrives (also known as RAID 0), improve the
reliability over using just one drive, but even with spanned drives it can take hours to
recover from some types of disk drive failures.
The prices of good servers are at an all-time low compared to the rest of the hardware
market, and leasing plans abound. Buying or leasing a server with 2 to 4 CPUs, 128MB or
more of ECC memory, RAID 5, and internal backup is a smart investment in reliability and
scalability for the servers in line-of-business systems. An example is a Dell PowerEdge
4200 with two Pentium II 300MHz processors, 256MB of ECC RAM, three 4GB SCSI hard drives,
and a 4MB Raid 5 controller, which prices out at around $8,000.
In your network architecture, you gain reliability and scalability by designing your
network with partitions. Partitioning breaks the Ethernet network into isolated small
clusters of nodes that limit traffic congestion and limit the spread of problems. The
best way to partition a modern business network is with an Ethernet switch. How it works
isn’t particularly important, but a switch replaces a hub and provides each node on the
network with its own isolated and uncontested path to its destination. Today, the price
per port of a 10Mbps Ethernet switch is about the same as that of a 100 Mbps hub.
The ideal combination for a line-of-business network is a switch with an adequate number
of 10Mbps ports for your client PCs and with some 100 Mbps ports for the file and
application servers. For example, Intel’s 8-port SS110TX8 switch includes two 100 Mbps
ports and has an estimated price of just under $700. You can combine hubs and switches
so that your busiest PCs get switched ports.
Admin Only. If your applications run more to letters, spreadsheets, and
presentations than to minute-by-minute commerce, an administrative network is more suited
to you since it carries a smaller load of data with a less critical impact than a business network.
