Wide Area Network (WAN)

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Where a LAN operates at a single site, a wide area network (WAN) spans multiple geographic locations.

• E.g., the Internet, a global network of networks
• network of networks, connected by long-distance links
• A company dedicated to facilitating access to the Internet from local networks is called an Internet Service Provider (ISP)
• Most private or enterprise WANs use cabling and equipment leased from an ISP to interconnect two or more LAN sites
  • E.g., a company might use a WAN to connect branch office sites to the LAN at its head office
• WAN could link two or more large LANs or for remote workers connecting to LAN from public network
• WAN links used to connect datacenters to one another