Computer Networks

Broadcast networks have a single communication channel that is shared by all the machines on the network.

A distributed system comprises multiple autonomous computers that communicate through a computer network. It appears to the user as a single computer. World Wide Web is an application of distributed system in which everything looks like a webpage. WWW runs on top of the network.

In a connection oriented service, the server first executes LISTEN to indicate which is prepared to accept incoming connections. After this execution, the server process is blocked until a request for connection appears.

IEEE802.16 is the wireless broadband standard authorised by IEEE. The work group is to develop standards for Wireless Metropolitan Area Networks.

TCP and UDP are parts of transport layer. TCP is a reliable connection oriented protocol that allows a byte stream originating from one machine to be delivered to the other machine without any error. UDP is an unreliable and connectionless protocol.

Presentation layer is concerned with the syntax and semantics of the information transmitted.

Third generation wireless network is digital, and it is used for transmitting both data and voice.

A base station is a radio receiver/transmitter that serves as the hub of the local wireless network. Access point includes special purpose hardware as well as general purpose computers that are configured to act as base stations or transceivers for wireless LANs.

NNTP (Network News Transfer Protocol) protocol is used for moving USENET articles around. USENET is a worldwide distributed internet discussion system.

Baud is the number of times a signal state is changed in a communication channel.

Repeaters are used to connect two or more network segments of any media type.

DHCP (Dynamic Host Configuration Protocol) is used to configure network devices to communicate on an IP network. A DHCP client uses the DHCP protocol to acquire configuration information such as an IP address, a default root and one or more DNS server addresses from a DHCP server. The DHCP client then uses this information to configure its host. Once the configuration process is complete, the host is able to communicate on the internet.

In a mesh network topology, each of the network node, computer and other devices are interconnected with one another. Every node not only sends its own signals but also relays data from other nodes.

Gopher is a protocol designed to search, retrieve and display documents from remote sites on the Internet. The Gopher was created as a piece of software to utilise some of the services that were becoming available on the Internet.

In a WAN, hosts are connected by a subnet. Subnet comprises communication lines (copper wire, optical fibre, etc.) and switching elements. Switching elements are connected with two or more communication lines. This switching element is known as router. Router selects the outgoing line for data transmission.