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WAN Technologies and Service Providers

CCNA: 0 to Hero - Comprehensive Network Engineering Bootcamp

Lesson 47: WAN Technologies and Service Providers

Wide Area Networks (WANs) connect dispersed LANs. Since the distance is great, organizations rent bandwidth from service providers (SPs).

Key WAN Technologies

  • Leased Lines: Dedicated, point-to-point physical circuits (e.g., T1/E1). Expensive but guaranteed bandwidth.
  • Ethernet WAN (Metro Ethernet): SPs extend Ethernet over their fiber backbones, allowing organizations to use standard Ethernet interfaces for WAN connectivity.
  • MPLS (Multiprotocol Label Switching): SP backbone technology that uses 'labels' for extremely fast forwarding decisions. Common for enterprise VPN services.
  • Internet VPNs: Using tunnels (like IPsec VPN) over the public Internet to create secure, private connections between sites.

The Customer Edge vs. Service Provider Edge

  • CPE (Customer Premises Equipment): Equipment owned and managed by the customer (e.g., the customer's router).
  • Demarcation Point (Demarc): The point where the SP's network ends and the customer's network begins (usually defined by a contract).