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Force-System Resultants and Equilibrium
Published in Richard C. Dorf, The Engineering Handbook, 2018
In some packet-switched networks, the path traversed by a packet through the network is established during a call-setup procedure, and the network is referred to as a virtual circuit-packet-switching network. Other networks provide datagram service, which allows users to transmit individually addressed packets without the need for call setup. Datagram networks have the advantage of not having to establish connections before communications take place, but have the disadvantage that every packet must contain complete addressing information. Virtual-circuit networks have the advantage that addressing information is not required in each packet, but have the disadvantage that a call setup must take place before communications can occur. The datagram is an example of connectionless service, while virtual circuit is an example of connection-oriented service.
Packet switched networks
Published in J. Dunlop, D. G. Smith, Telecommunications Engineering, 2017
The topology of Fig. 13.2 is an example of a store and forward packet switched network as each node stores data until a complete packet is received and then queues the packet for forwarding to a neighbouring node. Clearly physical links must be provided between the individual nodes and there are essentially two packet transmission techniques which can be identified. A virtual circuit transmission system is one in which a path is set up between soure and destination and all packets follow the same path and arrive in the sequence in which they were transmitted. A datagram transmission is one in which individual packets are transmitted by whatever route is available when they are presented for transmission. No fixed route is set up and each intermediate node decides on the appropriate path, according to some routing algorithm. In the case of a datagram the packets do not necessarily arrive in the order in which they are transmitted, and each packet must identify its position in the transmitted sequence.
Wireless networking
Published in Matthew N. O. Sadiku, Optical and Wireless Communications, 2018
As a connection-oriented technique, a virtual circuit must be set up and established across the ATM network before any data can be transmitted from source to destination. An ATM connection is identified by two labels to the virtual channel identifier (VCI) and virtual path identifier (VPI). The relationships between a physical transmission path, VPIs, and VCIs are shown in Figure 6.6. The physical path can be a coaxial cable or fiber-based SONET. A physical path contains a certain number of virtual paths. Each virtual path has many virtual channels.
A Survey on Packet Switching Networks
Published in IETE Journal of Research, 2022
In a datagram packet switching network, the information is transmitted in the enclosed small packets from one place to another place and uses different paths for delivery. The packets reach the destination unordered. TCP/IP is an example of datagram packet switching networks. Whereas in virtual-circuit networks, the data packets travel in a sequence through a fixed path. Most of the technologies use the data-link layers addressing. This network is also known as a connection-oriented packet switching network.