For Dummies CCNA Certification All-In-One 978-0-470-48962-8 User Manual
Product codes
978-0-470-48962-8
Chapter 1: Wide-Area
Networking Basics
Networking Basics
Exam Objectives
✓
Defining wide-area networking
✓
Explaining WAN connection types
✓
Describing WAN protocol encapsulation methods
✓
Introducing Cisco router cabling standards
✓
Identifying AUX and COM port connectors
✓
Understanding popular DSL technologies
✓
Recognizing the differences between DCE and DTE devices
Introducing WANs
A
wide-area network (WAN) is a connection between two or more
local-area networks (LANs) spanning across a large, spread-out
local-area networks (LANs) spanning across a large, spread-out
geographical area. A single LAN is usually considered to be confined to the
same building or office that does not communicate over public transportation
methods. A metropolitan-area network (MAN) limits its communications to
a specific city function or campus area, while a WAN uses dedicated leased
lines from telephone companies to establish links between geographically
dispersed LANs and/or MANs. WAN technologies are generally represented
by the three lower layers of the OSI model, namely, the network, data link,
and physical layers.
same building or office that does not communicate over public transportation
methods. A metropolitan-area network (MAN) limits its communications to
a specific city function or campus area, while a WAN uses dedicated leased
lines from telephone companies to establish links between geographically
dispersed LANs and/or MANs. WAN technologies are generally represented
by the three lower layers of the OSI model, namely, the network, data link,
and physical layers.
The Internet is the best example of a WAN and is the largest public
network on the planet. As you can see in Figure 1-1, private WANs are used
to establish permanent communications links between company sites and
branch offices. Using routers, traffic is managed and sent to the proper
destination LAN. The traffic is then transferred to LAN switching devices
until the data reaches the intended recipient. Private WANs may use a
number of methods to connect to remote sites, such as dedicated telephone
lines, ATM, Frame Relay, and satellite links. Private WANs may also use
public networks to communicate. Setting up an encrypted VPN over a local
ISP’s DSL service or dialup connection is another cost-friendly alternative
for secure communications.
network on the planet. As you can see in Figure 1-1, private WANs are used
to establish permanent communications links between company sites and
branch offices. Using routers, traffic is managed and sent to the proper
destination LAN. The traffic is then transferred to LAN switching devices
until the data reaches the intended recipient. Private WANs may use a
number of methods to connect to remote sites, such as dedicated telephone
lines, ATM, Frame Relay, and satellite links. Private WANs may also use
public networks to communicate. Setting up an encrypted VPN over a local
ISP’s DSL service or dialup connection is another cost-friendly alternative
for secure communications.
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