widearea

Wide area networking, commonly abbreviated WAN, is a telecommunications network that spans broad geographic areas and connects multiple local area networks (LANs) or metro area networks (MANs). WANs enable organizations to extend internal networks to remote offices, data centers, cloud services, and partner networks. They rely on public or private transmission facilities, including leased lines, fiber, satellite, and cellular links, and can traverse national borders. WANs differ from LANs by covering larger distances and often involve telecommunications carriers or service providers.

Common WAN architectures include hub-and-spoke and full-mesh topologies. Traditional WANs used dedicated leased lines and circuits such as T1/E1 or SONET/SDH. Modern WANs rely on IP transport and virtual private networks over the public internet, and increasingly use MPLS for performance and reliability. Software-defined WAN (SD-WAN) abstracts transport networks, enabling centralized policy control, application-aware routing, and easier hybrid connectivity to branch offices and cloud services.

Performance considerations include latency, jitter, bandwidth, and packet loss. Quality of service (QoS), traffic engineering, and WAN optimization help ensure acceptable performance for real-time applications such as voice and video. Security includes encryption for data in transit, site-to-site VPNs, firewalls, and remote access controls, with growing emphasis on zero-trust principles for branch and cloud connectivity.

Deployment models range from private WANs operated by a single organization to managed WAN services provided by telecom carriers. The rise of cloud computing and remote work has driven adoption of SD-WAN, cloud connectivity options, and more flexible, software-defined management. Trends include integration with 5G networks and satellite links for remote or underserved locations.