Page 19 - Handout Computer Network.

communication capabilities that used to be possible only if people were in the same physical office.
Collaboration software provides access to real-time information and resources that allow meetings
to be held remotely instead of in person. Wide-area networking has also created a new class of
workers called telecommuters—people who never have to leave home to go to work.
WANs are designed to do the following:

• Operate over large, geographically separated areas
• Allow users to engage in real-time communication with other users

• Provide full-time remote resources connected to local services
• Provide e-mail, World Wide Web, file transfer, and e-commerce services

Here are some common WAN technologies:

• Modems
• Integrated Services Digital Network (ISDN)

• Digital Subscriber Line (DSL)
• Frame Relay

• T (U.S.) and E (Europe) carrier series—T1, E1, T3, E3, and so on
• Synchronous Optical Network (SONET)—Synchronous Transport Signal level 1
(STS-1) (Optical Carrier [OC]-1), STS-3 (OC-3), and so on

https://www.youtube.com/watch?v=6TF2ph6jiEI

2.4.3 Metropolitan-Area Networks (MANs)

A MAN is a network that spans a metropolitan area, such as a city or a suburban area. MANs
are networks that connect LANs separated by distance and that are located within a common
geographic area, as shown in Figure 2-3.
For example, a bank with multiple branches might use a MAN. Typically, a service provider
connects two or more LAN sites using private communication lines or optical services. A MAN also
can be created using wireless bridge technology by beaming signals across public areas. The higher
optical bandwidths that are currently available make MANs a more functional and economically
feasible option than in the past.
The following features differentiate MANs from LANs and WANs:

• MANs interconnect users in a geographic area or region larger than that covered by a
LAN but smaller than the area covered by a WAN.
• MANs connect networks in a city into a single larger network (which can then also offer
efficient connection to a WAN).

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