Advanced Computer Networks

UNIT I

1. Types of Networks

2. Network Design Issues

3. Design Tools

-Surabhi R. Gosavi

What does Computer Network mean?

A computer network is a group of computer

systems and other computing hardware devices

that are linked together through communication

channels to facilitate communication and

resource-sharing among a wide range of users.

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Types of Networks

Networks are commonly categorized based on

their characteristics:

Local Area Network (LAN)

Wide Area Network (WAN)

Metropolitan Area Network (MAN)

Personal Area Network (PAN)

Campus Area Network (CAN)

Home Area Network (HAN)

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Local area network (LAN) : connects computers

and devices in a limited geographical area such as

a home, school or office building

wide area network (WAN) : covers a large

geographic area such as a city, country, or spans

Metropolitan area network (MAN) : is a large

computer network that usually spans a city or a

large campus

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A personal area network (PAN) is a computer

network used for communication among computer

and different information technological devices

close to one person. Some examples of devices

that are used in a PAN are personal computers,

printers, fax machines & telephones.

A campus area network (CAN) is made up of an

interconnection of LANs within a limited

geographical area.

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A home area network (HAN) is a residential LAN

used for communication between digital devices

typically deployed in the home, usually a small

number of personal computers and accessories,

such as printers and mobile computing devices.

A storage area network (SAN) is a dedicated

network that provides access to consolidated,

block level data storage & used to make storage

devices, such as disk arrays and tape libraries.

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Network Design Issues

1. Data Transfer Rules- The protocol used mustdetermine the number of channels needed andthe priorities to be used. This is based on the modeof communication (simplex, half-duplex and full-duplex)

2. The protocol that the layers use must be able tocorrect the sequence of the packets received if theyare not in correct order.

3. Another major issue is the maximum size of datathat can be sent and received at one go. This leadsto the need for segmentation at the sending end andre assembly at the receiving end.

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4. The problem is that if the sending packets are

too small in size, then the process becomes

inefficient.

5. A The sender and receiver identification must be

made possible for each layers. This can be

achieved by some form of addressing.

B common form of error control and error

correction on both the sending and receiving

ends.

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6. Rate of sending and rate of receiving must

match. If the rate of sending is too high that the

receiver cant cope up, it leads to congestion and

packet loss. Flow control can be used in these

cases.

7. Choosing the best possible route between the

sender and the receiver when more than one

path is available for data traversal

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Network Design Tools

Networks are a complicated mix of applications,

protocols, device and link technologies, traffic

flows, and routing algorithms.

There may be tens of thousands of feasible

configurations, each with different performance

attributes and costs.

Network design tools analyzes what is happening

in the network and predicts future behavior.

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WHO USES NETWORK DESIGN TOOLS?

Depending on the situation, concepts of the ideal

network, design tool can vary greatly :

Network managers and engineers

To operate the networks, troubleshoot and solve

performance problems

Network designers

To build new networks or modernize existing ones

&try to reduce design time and improve design

accuracy

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Researchers

To reduce development costs and risks, to test

the effects of new or modified protocols, devices,

architectures, component designs, and traffic

models in the lab

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WHAT GENERAL-PURPOSE TOOLS DO?

show which links and devices are over- and

underused

show how (un)balanced loads affect links and

devices

show the effects of link or device failures

show how changes in topology, device upgrades,

or expansion will affect performance

predict link and device throughput and utilization

model LAN, frame relay and IP13

Examples

Analytical Engine’s NetRule and NetRule Viewer

Compuware’s Comnet III, EcoPredictor, and

EcoProfiler

NetCracker’s Designer and NetCracker

Professional

Opnet Technologies’ Modeler, IT Decision-Guru,

and Netbiz

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Thank You…!!!

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