This chapter covers the following subjects:
OSI Layer 1 for Point-to-Point WANs: This section explains the physical cabling and devices used to create the customer portions of a leased circuit.
OSI Layer 2 for Point-to-Point WANs: This section introduces the data link layer protocols used on point-to-point leased lines, namely HDLC and PPP.
Frame Relay and Packet-Switching Services: This section explains the concept of a WAN packet-switching service, with particular attention given to Frame Relay.
In the previous chapter, you learned more details about how Ethernet LANs perform the functions defined by the two lowest OSI layers. In this chapter, you will learn about how wide-area network (WAN) standards and protocols ...