Overview
As the enterprise grows beyond a single location, it is necessary to interconnect the LANs in the various branches to form a wide-area network (WAN). This module examines some of the options available for these interconnections, the hardware needed to implement them, and the terminology used to discuss them.

There are many options currently available today for implementing WAN solutions. They differ in technology, speed, and cost. Familiarity with these technologies is an important part of network design and evaluation.

If all data traffic in an enterprise is within a single building, a LAN meets the needs of the organization. Buildings can be interconnected with high-speed data links to form a campus LAN if data must flow between buildings on a single campus. However, a WAN is needed to carry data if it must be transferred between geographically separate locations. Individual remote access to the LAN and connection of the LAN to the Internet are separate study topics, and will not be considered here.

Most students will not have the opportunity to design a new WAN, but many will be involved in designing additions and upgrades to existing WANs, and will be able to apply the techniques learned in this module.

Students completing this module should be able to:

  • Differentiate between a LAN and WAN
  • Identify the devices used in a WAN
  • List WAN standards
  • Describe WAN encapsulation
  • Classify the various WAN link options
  • Differentiate between packet-switched and circuit-switched WAN technologies
  • Compare and contrast current WAN technologies
  • Describe equipment involved in the implementation of various WAN services
  • Recommend a WAN service to an organization based on its needs
  • Describe DSL and cable modem connectivity basics
  • Describe a methodical procedure for designing WANs
  • Compare and contrast WAN topologies
  • Compare and contrast WAN design models
  • Recommend a WAN design to an organization based on its needs