ABSTRACT
Two types o f networks can be used to transport video/data conferencing signals, circuit-switched and packet-switched. In this chapter, we will discuss circuit-switched networks; in the next, we will discuss packet switching. Until Ethernet really became established, in 1979, the concept of packet switching was scarcely implemented anywhere. Today, packets traverse LANs and WANs all over the world; indeed, many people use the word networking to refer to packet-switched service exclusively, without acknowledging that circuit switching, a different type of networking, is older by almost a century.
