Time for another e-mail from the Ask InetDaemon mailbag:

Dear InetDaemon,

I would like to know the difference between
LAN protocols and WAN protocols.

Local Area Networks

The terms Local Area Network (LAN) and Wide Area Network (WAN) are general descriptions of geographic size of the network and to some extent, the protocols in use.  The acronym LAN tends to be used to refer to a network that encompasses a single room or a building at distances measured in feet or meters.  A LAN is most often used to connect computer workstations and servers.  Typically, Physical Layer protocols that are high speed and transmit across short distances are used in LANs.

Examples of Physical Layer protocols used in LANs include:

  • Ethernet
  • Fast Ethernet
  • Gig Ethernet
  • WiFi
  • FDDI
  • Token Ring

Note that it is possible to use ATM in LAN Emulation mode (ATM LANE) in a LAN. ATM is most often used in WANs, but there are ATM LANE based networks out there.

Wide Area Networks

The acronym WAN is used to refer to networks spanning much areas larger than a LAN does and often include circuits provided by a telecommunications carrier or a private leased line.  Protocols that can transmit across longer distances measured in miles or kilometers are used to build WANs.  Examples of Physical Layer protocols used to build WANs include:

  • X.25
  • Frame Relay
  • T-carrier (T1, T3 etc.)
  • ISDN
  • DSL
  • ATM

Learn More at InetDaemon.Com

InetDaemon.Com has plenty of tutorials on LANs, WANs and all the protocols used to build them.