Networking Concepts

Network Environment Design Considerations

Network Environment Design Considerations

Network and internetwork design must take many factors into consideration: the desired physical location of the computers comprising the network, the volume of projected communications traffic between nodes, communications traffic patterns, and the possibility of connections to other types of nodes (such as those in a public data network) are just some of the criteria to consider.

These factors will affect your choice of NS network type (LAN, Token Ring, FDDI, 100VG-AnyLAN, 100Base-T, Point-to-Point, X.25) as well as choice of specific links. They will also affect how you design your network layout. You may want to create subnetworks within your network by configuring IP subnet addresses. You may, on the other hand, need to join several networks together to form an internetwork or internet.

Line Speed

Line Speed is a measure of the rate at which data is transmitted by a physical link (usually measured in kilobits or megabits per second). The maximum line speed varies among different NS links. Line speed may therefore influence your choice of link. Although line speed does not indicate the exact throughput of a particular link, it can be used on a comparative basis to indicate relative throughput.

In general, an IEEE 802.3/Ethernet LAN or Token Ring network will be faster than a Point-to-Point or X.25 network because the bus or ring topology provides a faster routing mechanism than a series of Point-to-Point hops. FDDI, 100VG-AnyLAN, and 100Base-T links will be an order of magnitude faster than LAN or Token Ring. Links using leased lines will have a higher line speed than links using normal telephone lines.

Consult your Hewlett-Packard representative for line speeds and the most up-to-date performance data for various links.

Geographical Location

The geographical location of the computers that will be part of your network or internet will be an important factor in deciding both the physical topology and the link types that you should use.

If all of the nodes you want to connect are located relatively close to each other (in the same building, for example) you might choose to connect them via a LAN, Token Ring link, 100VG-AnyLAN, or 100Base-T.

Another option for nodes located in the same geographic location is to use hardwired (direct-connect) Point-to-Point links. You might wish to

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Chapter 2