There are three primary components to understanding networks: 1. Physical Connections; 2. Network Operating System; and 3. Application Component.

1. Physical Connections

The physical components are the network topology and network connecting devices, which include network interface cards (NIC), cabling, connections, and all other hardware to connect the computers.

Topologies. The different methods of connecting computers into a network are called topologies. Each topology has certain advantages and disadvantages that must be considered as one networks an office. These topologies are changing and new hybrid topologies are being developed combining the best of these topologies

Bus topology computers are connected together to a central cable called a bus. The bus topology is one of the most common, and doesn’t require as much cable as other systems; thus, it is less expensive. As new computers are added, they are connected to the main backbone, or bus. The system continues to work even if one of the client’s cables fails. However, the whole network stops if the main cable or bus is severed or disconnected. The system may slow down as more data is transferred along this one main connection.

The ring topography connects each PC to two other PC’sin a ring formation. Each PC is set up to pass data from one machine to the next in this relay type of system. Each computer has an in and out port. If one PC fails, the entire system fails. This system uses less cable than the others and thus, is less costly. Most integrators use hybrid ring systems.

In a star network, all the computers are connected through a central hub to the server. The advantage to this system is that if one cable or computer is disconnected the entire network continues to function. This configuration is considered one of the most reliable; however, it uses a lot of cable. Thus, it is more expensive. If the central hub fails, the system will not function. Remember that new configurations are being developed and that many networks use a combination or hybrid of the above networks to maximize performance and reliability.

Network Connecting Devices. There are a number of network physical components used to network computers. They are network interface cards, cabling, routers, bridges, and hubs.

Network Interface Cards (NIC).Network interface cards are the link between your computer and the cabling to connect your computers to the other computers on the network. There are well over 50 network cards available. When choosing a new card - chose the fastest technology and one that is compatible with Windows XP and Vista. Ethernet is a system of protocols for a computer that allows workstations to connect through NICs to other workstations. Ethernet systems are popular because they are relatively inexpensive. The data transmission rate is at 10 MBPS or higher, and uses the bus or star topology.

Token-Ring, developed by IBM, is more expensive then Ethernet, but transmits data at 16 MBPS or higher. FDDI stands for Fiber Distributed Data Interchange and requires fiber optics cabling to work. Data transmission on FDDI is 100 MBPS and faster. ATM stands for Asynchronous Transfer Mode and can transfer data from 25 MBPS up to 155 MBPS. It is predicted that the future speeds will be 2 Gigabytes. It appears to be the emerging standard, but still faces inoperability between vendors and backward compatibility issues.

Cabling (wire and wireless). To connect the nodes or workstations of your computer network, you need cabling. Cabling here is referring to both actual physical cabling and the “wireless” variety. In either situation, “cabling” is needed to connect the computers. Wire provides the best security and integrity in data transmission at the present time. The two primary types of wire cabling are coaxial and twisted pair. Coaxial cabling is generally less expensive, uses fewer other connector devices, and provides good shielding from outside interference. However, it is more difficult to work with and to install in the walls. Twisted pair cabling has several pairs of wires that are braided within a plastic cover. Direct cable networking is supported by Windows XP and Vista™, and enables two computers to network using either the serial or parallel ports. The parallel ports permit faster transmission but are limited to 50 feet, whereas the serial port cable can extend up to a thousand feet.

Fiber Optic network cable uses light instead of electrical impulses to carry the network signal. Fiber optic is a thin glass filament that connects to optical connectors for each of the computers. Fiber optic’s signal strength enables a signal to be run a long distance without any weakening. Because of its signal strength, data speeds can increase from 10 MBPS (10,000,000 bits per second) to over 1G (1,000,000,000 bits per second), which will be sufficient for future network data needs. Fiber optic connectors and cabling are expensive, but may be the choice if electrical interference is present or distance between computers is significant.

Light wave connections use either infrared light beams or lasers to communicate between two computers. Light waves cannot penetrate walls or ceilings, are subject to interference, and network speeds can be quite slow.

Radio wave connections use radio signals to transmit data. They can penetrate walls and ceilings and can transmit from several hundred feet to several miles. Radio-wave connections are typically used when the need to connect mobile laptops in a business is required, such as recording the inventory in nearby warehouses with laptop computers. Radio wave networking can be used to connect buildings and mobile units within a several mile radius. Radio wave connections are subject to interference of other nearby radio transmissions.

Gateways are computers that convert one protocol to another protocol. They can convert data from TCP/IP to another protocol or e-mail from one protocol to another.

Hubs, Routers and Bridges are hardware components that connect network segments together to send and receive data between different LANs and WANS. A hub is a connecting device to connect workstations and servers to form a network. They can be used for client/server or peer-to-peer systems. To connect networks together one would use a router or bridge to exchange data information. Routers are generally used to connect and send information from a LAN to the WAN. Bridges are hardware devices that break a large LAN into smaller ones for better management. To connect WANS together; connectors called DSU/CSU’s are connected to data transmission lines such as ISDN, etc.

2. Network Operating System

In order to communicate on a network, computers must use the appropriate operating protocol selected for the network. This protocol enables the computer to exchange information and ensure correct data transmission. The network operating system (NOS) is the controlling software that enables a server to accommodate multiple clients and provide the communication network between them. The most common network protocols and the products supporting the protocol are: · TCP/IP - Unix, Windows NT™ server, Linux, Internet products. (TCP/IP is the protocol being used on the Internet and for intranets) · IPX/SPX - Novell NetWare™, Windows NT Server™. · NetBIOS - OS/2 WARP Server™, Windows NT Server™.

3. Application Component The value of networking lies in the capability of sharing up-to-date information, software and hardware resources with other users on the system. The primary application software networking programs used in the legal profession are word processing, time & billing, calendar/docket/address book, E-mail, document management, conflict management, litigation support, and peripheral sharing such as printers, CD-ROM, PC fax systems, modems and any other hardware. See the prior section on Network Applications for the Practice of Law for a detailed discussion of these applications.

3.  Application Component

The value of networking lies in the capability of sharing up-to-date information, software and hardware resources with other users on the system. 

The primary application software networking programs used in the legal profession are word processing, time & billing, calendar/docket/address book, E-mail, document management, conflict management, litigation support, and peripheral sharing such as printers, CD-ROM, PC fax systems, modems and any other hardware.  See the prior section on Network Applications for the Practice of Law for a detailed discussion of these applications.