Local Area Network Design
Most of us already have or will at some point in our careers, be responsible
for selecting LAN hardware. This often means that you must plan details ranging
from the number of servers to the number of network plugs in a room. If you can
write a clear, detailed proposal and are a bit lucky, someone else can follow
your directions, buy, install, and test the equipment. If it all works, you look
great; if you forget about file backup, power backup, or the network connection
in the bosses' office, good luck.
The purpose of the following exercise is to develop some experience in the
analysis and design of the physical components necessary to
implement a typical, small local area network (LAN). The exercise
begins with an analysis of equipment needs that begins with a site
evaluation of wiring and equipment needs, and concludes with a design
specification of materials and a cost list for the proposed LAN. The goal is to
produce a detailed specification for the purchase and installation of the LAN
hardware and software.
Network configurations are highly adaptable, supporting a variety of
configurations and installation site needs, represent a significant initial
expense, and require long-term technical support. The designer of a network must
recognize the physical limits of the technology used, the resource needs of
expected users, and the overall cost of equipment and installation. The planning
of a LAN should include the following:
- determination of hardware and software to be supported
- needs assessment to determine parameters such as amount of local and
networked disk resources necessary
- diagram locating current and future machines to assist in selecting
topologies, cabling and network access methods, and to locate connections at
Tanenbaum illustrates topologies in Chapter 1 and gives an opaque discussion
of Ethernet hardware. Several texts in LF-111A give LAN planning discussion.
LAN Hardware - The minimum LAN hardware consists of:
- Computer - At least two that are connected by the LAN. In a
client-server relation, the resources (i.e. disk, printer, etc.) of the server
are shared with the client. In a peer-to-peer relation, the resources of
either peer computer can be shared with another.
- Connection medium - Use both wire and wireless. Wire
typically is Category 5 cable for connecting Ethernet to each computer at the
desktop and optical fiber between communication hubs. Wireless requires
transmitters/receivers on each desktop computer and a base station
receiver/transmitter to connect with other wireless or wire LAN segments.
- Network Interface Card (NIC) - Each device on the LAN (computer,
printer, file server, etc.) requires a network interface card. The card
provides a place to physically connect the wire to the device. It also
uniquely identifies each NIC by a number known as a MAC address.
- Concentrator, hub, or switch - A network hub or switch connects the
many networked devices (computer, printers, etc.) together on a LAN.
Wires, as the spokes of a wheel, go from the NICs on each networked devices to
the hub or switch. Another wire connects each hub or switch to a router,
to form a larger network. Some connection mediums such as Ethernet allow
directly connecting two computers using a crossover cable alone.
LAN Software - LAN software allows one computer to communicate with
another and is integrated into all operating systems such as Windows 2000/XP,
Linux, etc. Specialized server software is generally required when implementing
a client/server relation. In the Windows client/server world, Windows Server
2000/XP software would be needed on all server computers while Windows 95, 98,
2000 ME, Professional, XP, Apple, Unix, etc. would generally be used on each
client computer. All Windows operating systems versions are also capable of
supporting peer-to-peer relations.
Develop a LAN proposal that details the cost of network hardware, providing
sufficient information for ordering and installing equipment by someone other
than yourself. The LAN should include a minimum of:
- one resource server with file backup
- 5 workstations
- both wire and wireless mediums
- power protection
- Internet connection (DSL, broadband, etc.)
Follow the format given in the Analysis, Design, and Implementation parts.
- Cover Page - Your name, date, and Homework 1. Staple all
- Site log
- Needs assessment
- Site diagram
- Include enough detail (number of cables, room number, location of
network plug, etc.) for someone else to install equipment
- Access methods (wire and wireless)
- Order form listing enough information for someone else to order the
correct equipment and software. Vendor Web pages are not acceptable. Click
here for a copy of the order form.
Analysis (25 pts)
The basic planning steps for the LAN are listed below. The LAN site may be
off campus area or a location on campus but should reflect a real location
though not an existing LAN. Where needed data is not available make reasonable
estimates (for example, how many computers would one expect to be located in a 9
square meter office).
Site Log - Computers, Power, Communications
- List of existing computer equipment at the installation site.
List the following items, using one line for each existing workstation
systems (maximum of five systems):
- System ID number (to be assigned as required)
- System (brand name or other identifier)
- Room location
- User (optional)
1 Dell 7500
Computer Science LF11A
2 Dell 9000
- Existing software used - Give name and type
- Word - Word processor
- Excel - Spreadsheet
- Existing power service to area. Note whether conditioned, UPS,
etc. and estimate on amperes service to area.
- List any existing cable and pathways (e.g. a. new construction,
b. communications cable is Category 5 in enclosed cableway, c. cable is
undetermined type strung on floor).
- Required software - May include some or all of existing plus new
Examples: LookOut -
Word - Word Processor
Flight Simulator - Game
- Workstation requirements - Number and general use. Minimum
of 5 workstations.
Office applications - 5
Software development - 2
- Server storage requirements - Estimate disk storage, estimate
individual needs of each to 10 mb
Usage for programs
Word 2010 - 36Gb
WordPerfect - 900mb
NetScape - 200mb
Super Mario - 50mb
Word - 250mb
NetScape - 50mb
Accounting - 150mb
- Printing requirements
Printer type or quality
required - Must printer attach to workstation?
Letter quality attached to 3 workstations
- Network load estimates - Bytes transmitted, on average to or from
active workstation (as bytes/minute, hour, etc.).
Estimated/hour average data access
13-15mb per hour
18-20mb per hour
- Communications options
Internet, Modem, Fax,
- Estimated power requirements for workstation, server, and printer
(include UPS or SPS)
Design (35 pts)
The primary design artifact consists of several drawings that serve to
document the topology, hardware type, location, number, and distances within
the area containing the LAN. The drawing should contain the following:
- Site Diagram
Diagram your site workstation, server and power locations. The diagram does
not need to be elaborate (blueprint quality not required) but should be
obvious to someone visiting the site (i.e. doors, computers, power, network
connection, etc. accurately placed). Assume that someone else will install the
wire/computers/power/etc. using the diagram while you are on vacation. A one
page diagram, neatly drawn, should suffice.
a. Show proposed server(s) and workstations location.
b. Estimated distance, note existing cable-ways, include falls
c. Indicate whether unused cabling exists, it's location, and
it's type (determine part number if possible) and whether it can be salvaged.
d. Indicate power locations (including power protection).
- Cable access methods - Add to copy of Site Diagram. Remember
the network infrastructure should include both wire and wireless mediums. The
final diagram should look similar to the one at right.
Complete for any of Arcnet, Token ring, Ethernet or other access methods.
a. Select a topology, cabling type and access method consistent
with your Needs Assessment. Overlay wiring installation on site
b. Show location of wire and lengths.
c. Show MAUs, hubs, switches, wireless base stations, Internet
connection, etc. and locations necessary to connect workstations to wire.
Indicate distances to verify that wire or wireless ranges are not exceeded.
Word can be used for simple drawings by clicking View, Toolbars and Drawing.
Implementation (40 pts)
The implementation artifact includes of the hardware specifications
required for purchase presented in an order form that would allow someone
naive of technique details to acquire the correct LAN components. Use the
supplied order form.
- Calculate Cost of Network Installation
Using the data developed above and available catalogs and online sites,
determine the cost of network wired and wireless plans. Provide enough
information for informed decisions to be made affecting whether all
buildings/rooms/workstations are to be wired, use existing wire, or wireless.
Remember that the network infrastructure should include both wire and wireless
- Operating Software
Select workstations and server software (Palm Pilot, Windows ME, Windows XP,
- File server/Workstations
Specify a complete server system and workstation hardware for your network
design. Indicate necessary details, such as make, model, CPU, memory caching,
bus, disk type, capacity of memory and disk, NIC, etc. Determine hardware
required for software and cost of each.
- Order Form
Using the data collected above prepare an order sheet for all software and
hardware components (cable, MAU's, server, operating software, etc.) showing
the following details:
Part Number Description Quantity Item Cost Item Total
Click here for a copy of the order form. Note
that it can be saved from the browser and information edited in any HTML
editor such as FrontPage.
Do not submit vendor's Web pages.
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