Networking: A Beginner's Guide
If you have any high-bandwidth users, consider keeping them on a segment
separate from the rest of the network (if appropriate) and also consider
upgrading the speed of that segment to 100 Mbps or 1,000 Mbps if needed.
As you start to implement the network, carefully watch the ratio of collision
packets to data packets. If the number of collisions on any segment climbs
5 to 7 percent of the total number of packets, performance is starting to
suffer, so you need to investigate the cause and find a way to decrease this
ratio. You can usually do so by breaking the segment into smaller pieces or by
configuring capable switches into what is called a virtual LAN (VLAN), unless
you know of another way to reduce the amount of traffic.
When choosing servers for a network, start by determining which NOS you will use.
For PC-centric networks, the decision is usually between Novell NetWare and Windows
family of servers. As discussed in Chapter 13, whenever possible, avoid using both,
because supporting two NOS systems makes managing the servers much more difficult.
You're better off compromising on a single NOS platform.
Next, list the various network services that your servers must provide. You need
to look for efficient ways to host these various services on your servers, balancing a
number of factors:
All else being equal, using more small servers to host fewer services each is
more reliable than using fewer large servers to each host many services.
Conversely, having more small servers increases your chance of having a server
fail at any given time.
Using more small servers is more expensive and requires more maintenance than
using fewer large servers.
If you plan to use more than one server, consider which services should be
redundant on another server or how you plan to deal with the failure of any
Using your assessment information, you can easily determine how much storage
capacity your servers will need. However, it's much harder to know how capable each
server should be in terms of processor power, installed RAM, and other features, such
as bus configuration. For these specifications, you need to rely on the advice of the NOS
vendor and the manufacturer of the servers that you are considering. Fortunately, both
Microsoft and Novell have published tests and recommendations for sizing servers
given different service and user loads. Many first-tier server manufacturers also have
such data to help you choose an actual server model and its specifications.