/wæn/
noun — "the network that stretches far beyond your office walls."
WAN, short for Wide Area Network, is a telecommunications network that connects multiple local area networks (LANs) over large geographic areas, such as cities, countries, or even continents. WANs enable data exchange between remote sites, branch offices, and cloud services, often relying on leased lines, MPLS, or Internet connections.
Technically, a WAN uses routing protocols like BGP and OSPF to manage traffic efficiently, ensure reliability, and optimize latency. Security measures such as VPNs (VPN) and firewalls (Firewall) are commonly deployed to protect data as it travels across public or shared networks.
Key characteristics of WANs include:
- Geographic reach: connects networks across cities, countries, or continents.
- Traffic routing: uses protocols like BGP and OSPF for path selection.
- Security: VPNs and firewalls protect data in transit.
- Bandwidth optimization: ensures efficient use of long-distance links.
- Redundancy and reliability: multiple paths and failover mechanisms.
In practical workflows, organizations use WANs to link branch offices, remote workers, data centers, and cloud applications, allowing centralized management and consistent access to corporate resources.
Conceptually, a WAN is like an interstate highway system connecting distant cities, allowing data to travel long distances quickly and reliably.
Intuition anchor: WAN extends your network’s reach far beyond the local office.