4WAN & network virtualization

• 4.1WAN and wide-area connectivity

  Compares the characteristics of closed-network services connecting sites over a leased line, wide-area Ethernet, and MPLS (label switching)-based IP-VPN, versus an Internet VPN, and builds the judgment to choose the optimal circuit and access method from the tradeoffs among cost, quality (bandwidth guarantee, latency), and security.

• 4.2Wireless LAN and mobile

  Covers the evolution of the IEEE 802.11 standards (a/b/g/n/ac/ax (Wi-Fi 6)), frequency bands and channels, SSID, encryption via WPA2/WPA3, roaming, the hidden node problem, and 5G/LTE mobile communication, building the judgment needed to design a wireless environment given interference and security requirements.

• 4.3Network virtualization

  Covers SDN, which separates the control and data-forwarding functions (via OpenFlow), SD-WAN, which centrally controls a multi-site WAN in software, NFV, which turns dedicated appliance functions into software, and VXLAN (VNI), which builds an L2 network as an overlay on top of L3, building the judgment needed to decide when to migrate from a traditional network.

• 4.4Cloud and edge

  Covers the IaaS/PaaS/SaaS service models and cloud connectivity methods (dedicated connection/VPN), the VPC (virtual network), edge computing, which performs latency-sensitive processing near the device, the CDN, which accelerates content delivery, and IoT/M2M, building the judgment needed to design network connectivity between on-premises and the cloud.