CCNA Cisco Certified Network Associate Study Guide - FTP Server

Wide Area Networks 479
Demarcation (demarc) The last responsibility of the service provider,
usually an RJ-45 jack located close to the CPE. The CPE at this point
would be a CSU/DSU or ISDN interface that plugs into the demarc.
Local loop Connects the demarc to the closest switching office, called a
central office.
Central office (CO) Connects the customers to the provider’s switching
network. A CO is sometimes referred to as a point of presence (POP).
Toll network Trunk lines inside a WAN provider’s network. It is a collection
of switches and facilities.
It is important to familiarize yourself with these terms, as they are crucial
to understanding WAN technologies.
WAN Connection Types
Figure 10.1 shows the different WAN connection types that can be used to
connect your LANs together over a DCE network.
FIGURE 10.1 WAN connection types
Dedicated
Circuit-switched
Packet-switched
Synchronous serial
Asynchronous serial, ISDN
Telephone
company
Synchronous serial
Service
provider