Strategic Network Operation

Anyone who's run a network operations group knows the frustration that accompanies

management inquiries about "our network strategy." To be successful, a strategic

network plan must define the services the network will offer the line operations of the

business.

Network, in computer science, techniques, physical connections, and computer

programs used to link two or more computers. Network users are able to share files,

printers, and other resources; send electronic messages; and run programs on other

computers. A network has three layers of components: application software, network

software, and network hardware. Application software consists of computer programs

that interface with network users and permit the sharing of information, such as files,

graphics, and video, and resources, such as printers and disks.

Network software consists of computer programs that establish protocols, or

rules, for computers to talk to one another. These protocols are carried out by sending

and receiving formatted instructions of data called packets. Protocols make logical

connections between network applications, direct the movement of packets through the

physical network, and minimize the possibility of collisions between packets sent at the

same time. These are some of the different types of Network software: Appletalk,

Arpanet, Bitnet, CWIS, Ethernet, IBM Token Ring netwrok, Internet, LAN, and

USENET. Also Class A, B, & C network refer to the different types of subnet protocol.

Local Area Networks(LANs), which connect computers separated by short distances,

such as in an office or a university campus, commonly use bus, star, or ring topologies.

Wide area networks (WANs), which connect distant equipment across the country or

internationally, often use special leased telephone lines as point-to-point links, and is the

biggest network.

When computers share physical connections to transmit information packets, a set

of Media Access Control (MAC) protocols are used to allow information to flow

smoothly through the network. An efficient MAC protocol ensures that the transmission

medium is not idle if computers have information to transmit. It also prevents collisions

due to simultaneous transmission that would waste media capacity. MAC protocols also

allow different computers fair access to the medium.

One type of MAC is Ethernet, which is used by bus or star network topologies. An

Ethernet-linked computer first checks if the shared medium is in use. If not, the

computer transmits. Since two computers can both sense an idle medium and send

packets at the same time, transmitting computers continue to monitor the shared

connection and stop transmitting information if a collision occurs. Ethernet can transmit

information at a rate of 10 Mbps.

The most significant - and successful - encroachment occurred when switched

Ethernet devices appeared on the scene. This approach multiplies rather than divides

bandwidth by the number of devices on the network and is the essential ingredient for

building truly scalable networks. These changes, along with the price benefits of using

copper (because virtually all ATM connections were fiber) and avoidance of ATM's

massive complexity, doomed ATM as the "end-to-end everywhere" solution it was long

purported to be.

Computers also can use Token Ring MAC protocols, which pass a special message

called a token through the network. This token gives the computer permission to send a

packet of information through the network. If a computer receives the token, it sends a

packet, or, if it has no packet to send, it passes the token to the next computer. Since there

is only one token in the network, only one computer can transmit information at a time.

One type of application software is called client-server. Client computers send

requests for information or requests to use resources to other computers, called servers,

that control data and applications. Another type of application software is called

peer-to-peer. In a peer-to-peer network, computers send messages and requests directly to

one another without a server intermediary.

All PC networking is based on the client/server concept, in which one computer

(the client) requests a service from another

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