13 - 238 CCNA 2: Routers and Routing Basics v3.1 Instructor Guide – Module 1 Copyright © 2004, Cisco Systems, Inc.
1.1.4 Role of Routers in a WAN
There are several encapsulations associated with serial lines:
HDLC
Frame Relay
PPP
SDLC
SLIP
LAPB
Some of the most common WAN technologies are as follows:
POTS
ISDN
X.25
Frame Relay
ATM
T1, T3, E1, and E3
DSL
SONET
Ask students to briefly explain each of the WAN technologies and discuss the differences
between technologies and encapsulations. They will be covered in detail in CCNA 4.
It is important to encourage student interest and enthusiasm in this TI. The world of WAN
technologies is briefly introduced. Many students will be familiar with one or more of the
technologies used. Many of these topics will be covered in CCNA 4 and students should be
encouraged to do additional research on one of these technologies and present it to the class.
1.1.5 Academy approach to hands-on labs
In the Networking Academy lab, all the networks are connected with a serial or Ethernet cable.
This allows the students to see and touch all of the equipment. In a real network, the routers
would not be in one physical location. In the Networking Academy lab, the serial cables are
connected back-to-back. However, in the real world the cables would be connected through a
CSU or DCE device.
Discuss the differences between real networking environments and the router lab setup. Help
the students visualize the components between the V.35 connectors. If they can understand
this picture, then they will realize that they are working with a complete WAN minus the carrier
services.