Session 37

Session 37
Date:22.7.2010

Activities:
- Discussed about needed in computer network communication.

• Network Interface Card (NIC)
• Wireless Network Interface Card
• Modem (internal and external)
• Hub
• Router
• Wireless Access Point

A network interface card (NIC) is a communication device that enables a computer or device to access a wired network (via cable)




• Wireless Network Interface Card

A wireless network interface card is a communication device that enables a computer or device to access a wireless network (via radiowave)



• Modem (internal and external)

Modem
A modem (a modulator/demodulator) lets you connect your computer to a standard telephone line so you can transmit and receive electronically transmitted data. It is the key that unlocks the world of the Internet and its World Wide Web, commercial online services, electronic mail (E-mail), and bulletin board systems (BBSes).

External modem.
This is the simplest type of modem to install because you don't have to open the computer. External modems have their own power supply and connect with a cable to a computer's serial port. The telephone line plugs into a socket on the rear panel of the modem.
Internal Modem
Most internal modems come installed in the computer you buy. Internal modems are more directly integrated into the computer system and, therefore, do not need any special attention. Internal modems are activated when you run a communications program and are turned off when you exit the program. This convenience is especially useful for novice users.
Internal modems usually cost less than external modems, but the price difference is usually small. The major disadvantage with internal modems is their location: inside the computer. When you want to replace an internal modem you have to go inside the computer case to make the switch.

• Hub
Hub
A hub is a communication device that is used for connecting wired computers or devices on a Local Area Network (LAN).A hub provides a common connection wireless computers or devices on a Local Area Network (LAN).

• Router

A device that forwards data packets along networks. A router is connected to at least two networks, commonly two LANs or WANs or a LAN and its ISP’s network. Routers are located at gateways, the places where two or more networks connect. Routers use headers and forwarding tables to determine the best path for forwarding the packets, and they use protocols such as ICMP to communicate with each other and configure the best route between any two hosts.Very little filtering of data is done through routers.


• Wireless Access Point

Wireless access points (APs or WAPs) are specially configured nodes on wireless local area networks (WLANs). Access points act as a central transmitter and receiver of WLAN radio signals.