Choose the optimal VPN service

This section defines Virtual Private Networks, describes their typical topologies, as well as requirements and decision points you should consider when either buying or building a VPN service.

You could build your own VPN or buy it as a service from a Service Provider. This section describes the customer perspective of typical Service Provider offerings including:

• Layer-3 VPNs implemented with MPLS/VPN or EVPN/VXLAN technology
• Layer-2 point-to-point or point-to-multipoint circuits
• Virtual LAN (E-LAN or VPLS) services

You might want to build your own VPN on top of Internet to keep the costs low, or do the same on top of provider-built VPN because you don't trust their skill. This section gives you an overview of most popular technologies you could use.

Want to use MPLS/VPN as your primary WAN with Internet-based VPN as a backup? Or run your own MPLS/VPN on top of DMVPN or IPsec because you have many internal tenants but don't own WAN infrastructure?

This section describes several hybrid VPN architectures, and introduces Software-Defined WAN - most commonly an orchestration layer on top of a proprietary hybrid VPN solutions.