d correctly. Comparing Circuit Switching and Packet Switching What does the future hold for circuit switching and packet switching? Circuit switching is superior to packet switching in terms of eliminating queuing delays, which results in completely predictable latency and jitter in the backbone. Given the trend toward real-time visual and sensory communication streams, this seems to be the most important characteristic for us to strive toward. With the large capaci- ties afforded by the new DWDM systems and other optical network elements, mini- mizing latency becomes more important than optimizing bandwidth via statistical multiplexing. (DWDM and other forms of multiplexing are discussed in Chapter 1.) We're likely to see the use of statistical multiplexing continue to increase at the edge and at the customer premises, as a means of economically integrating and aggregat- ing traffic from the enterprise to present it over the access link to the network. In the core, fiber-based and circuit-switched networks are likely to prevail. Table 3.1 briefly compares circuit switching and packet switching. As you look at the table, keep in mind that as we get more bandwidth, circuit-switched net- works do not have to be SO concerned with bandwidth efficiency. And as QoS is added to packet-switched networks, these networks are able to support real-time applications. Again, the prevailing conditions have a lot to do with what is best in a given network. Chapter 3 Establishing Communications Channels Table 3.1 Circuit Switching Versus Packet Switching Characteristic Circuit Switching Packet Switching Origin Voice telephony Data networking Connectionless or Connection oriented connection oriented Key applications Real-time voice, streaming media, Bursty data traffic that has long con- videoconferencing, video-on- nect times but low data volumes; demand, and other delay- and loss- applications that are delay and loss sensitive traffic applications tolerant Latency/delay/jitter Low latency and minimal delays Subject to latency, d