End systems are connected together by communication links. There are many types of communication links, which are made of different types of physical media, including fiber optics, twisted pair, coaxial cable and radio links. Different links can transmit data at different rates. The link transmission rate is often called the bandwidth of the link, which is typically measured in bits/second. The highest the bandwidth, the more is the capacity of the channel. End systems are not usually directly attached to each other via a single communication link. Instead, they are indirectly connected to each other through intermediate switching devices known as routers.
A router takes a chunk of information arriving on one of its incoming communication links and forwards that chunk of information on one of its outgoing communication links. In the jargon of computer networking, the chunk of information is called a packet. The path that the packet takes from the sending end system, through a series of communication links and routers, to the receiving end system is known as a route or path through the network. Rather than providing a dedicated path between communicating end systems, the Internet uses a technique known as packet switching that allows multiple communicating end systems to share a path, or parts of a path, at the same time. Similar to a router, there is another special machine called gateways used in the network that allows different networks to talk to the Internet, which uses TCP/IP.
Packet switching is used to avoid long delays in transmitting data over the network. Packet switching is a technique, which limits the amount of data that a computer can transfer on each turn. Packet switching allows many communications to proceed simultaneously. Each packet contains a header that specifies the computer to which the packet should be delivered and the destination is specified using computer’s address. Computers that share access to a network take turns in sending packets. On each turn, a given computer sends one packet.
IP uses this packet switching concept to deliver messages on the Internet If the destination address does not exist on the local network, it is the responsibility of that network’s router to route the message one step closer to its destination. This process continues until the destination machine claims the message packet.
A router takes a chunk of information arriving on one of its incoming communication links and forwards that chunk of information on one of its outgoing communication links. In the jargon of computer networking, the chunk of information is called a packet. The path that the packet takes from the sending end system, through a series of communication links and routers, to the receiving end system is known as a route or path through the network. Rather than providing a dedicated path between communicating end systems, the Internet uses a technique known as packet switching that allows multiple communicating end systems to share a path, or parts of a path, at the same time. Similar to a router, there is another special machine called gateways used in the network that allows different networks to talk to the Internet, which uses TCP/IP.
Packet switching is used to avoid long delays in transmitting data over the network. Packet switching is a technique, which limits the amount of data that a computer can transfer on each turn. Packet switching allows many communications to proceed simultaneously. Each packet contains a header that specifies the computer to which the packet should be delivered and the destination is specified using computer’s address. Computers that share access to a network take turns in sending packets. On each turn, a given computer sends one packet.
IP uses this packet switching concept to deliver messages on the Internet If the destination address does not exist on the local network, it is the responsibility of that network’s router to route the message one step closer to its destination. This process continues until the destination machine claims the message packet.
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