E-VPN, I-VPN, VPN, A-VPN explained
EVPN – This is a package VPN solution provided by Carries such as AT&T. Enhanced Virtual Private Network is actual a VPN provided over MPLS and isn’t encrypted. So it’s a virtual private network using MPLS over a carries network (Sonnet/SDH/ATM/Ethernet). If encryption is required then IPSec is required. So EVPN is basically a straightforward tunnel over a network using MPLS.
IVPN – This is Internet Protocol virtual private network, and this is an encrypted virtual private network. It’s the type of VPN that the person thought was the only one. It’s when a connection (tunnel) is made over the Internet using encryption to keep the traffic safe. It’s often set up between firewalls, but can be set-up between routers too.
The key here is EVPN’s are tunnels set-up across a carries own network, upon which it has a level of control, and is used to separate out all of its customer’s traffic. IVPN’s on the other hand, are tunnels across other people’s networks, where there is no control over where the traffic goes.
AVPN is the same as EVPN there’s just a difference in CPE ownership. In EVPN all hardware including CPE is owned by the telco (in this case AT&T). For AVPN the CPE is provided by the customer and is not managed. There are also some minor CDR pricing changes.