Data communications and Networking Chapter 10 Circuit Switching and Packet Switching References Book Chapter 10.1, 10.2, 10.5 Data and Computer Communications, 8th edition By william Stallings
1 Data Communications and Networking Chapter 10 Circuit Switching and Packet Switching References: Book Chapter 10.1 , 10.2, 10.5 Data and Computer Communications, 8th edition By William Stallings
Overview Networks are used to interconnect many devices We have checked with local area Networks Now, wide area networks Since the invention of the telephone, circuit switching has been the dominant technology for voice communications Since 1970, packet switching has evolved substantially for digital data communications. It was designed to provide a more efficient faclity than circuit switching for bursty data traffic. Two types of packet switching Datagram(such as todays Internet Virtual circuit such as Frame Relay aTm)
2 Overview • Networks are used to interconnect many devices. • We have checked with Local Area Networks. • Now, wide area networks — Since the invention of the telephone, circuit switching has been the dominant technology for voice communications. — Since 1970, packet switching has evolved substantially for digital data communications. It was designed to provide a more efficient facility than circuit switching for bursty data traffic. • Two types of packet switching: – Datagram (such as today’s Internet) – Virtual circuit (such as Frame Relay, ATM)
Switched communications Networks Long distance transmission between stations(called end devices") is typically done over a network of switching nodes Switching nodes do not concern with content of data Their purpose is to provide a switching facility that will move the data from node to node until they reach their destination(the end device) a collection of nodes and connections forms a communications network In a switched communications network data entering the network from a station are routed to the destination by being switched from node to node
3 Switched Communications Networks • Long distance transmission between stations (called “end devices”) is typically done over a network of switching nodes. • Switching nodes do not concern with content of data. Their purpose is to provide a switching facility that will move the data from node to node until they reach their destination (the end device). • A collection of nodes and connections forms a communications network. • In a switched communications network, data entering the network from a station are routed to the destination by being switched from node to node
Simple Switching Network Mainframe Personal computer 2 Server 3 Personal 5 Personal computer Switching E 4 Node 量 compute 7 F
4 Simple Switching Network
Switching Nodes Nodes may connect to other nodes or to some stations Network is usually partially connected -However some redundant connections are desirable for reliability Two different switching technologies Circuit switching -Packet switching
5 Switching Nodes • Nodes may connect to other nodes, or to some stations. • Network is usually partially connected —However, some redundant connections are desirable for reliability • Two different switching technologies —Circuit switching —Packet switching