Software

VPN systems may be classified by:

• the tunneling protocol used to tunnel the traffic
• the tunnel’s termination point location, e.g., on the customer edge or network-provider edge
• the type of topology of connections, such as site-to-site or network-to-network
• the levels of security provided
• the OSI layer they present to the connecting network, such as Layer 2 circuits or Layer 3 network connectivity
• the number of simultaneous connections