I am new in here and I hope to find my answer.
I'm working on sub ISP company which provide internet and ipvpn services to customers through infrastructure of main ISP.
We have a central data center which a lot of configuration in there and we have a router connected direct to ISP for internet and another router connected direct to ISP for DDA links which basically are l2vpn links for customers. so when a customer call us asking for internet link, we first ask main isp to connect the customer to our data center specfically to DDA router then by our own network setup we deliver the internet to the customer.
during the implementation of L2vpn with the main ISP, he provide us an ISP vlan to configure in our DDA router for the link between our company and main ISP. Also, he provide us a customer vlan to configure in the customer edge router between main isp and customer.
Please click on this link https://ufile.io/e0n7d to download an example of L2vpn setup.
My question now that I am really thinking how the main ISP is doing the L2vpn of connecting the customer to our DDA router, which technique he is using?
I know it's not any kind of mpls because they offer mpls l2 with higher price.
I'm looking forward to hear positive feedback from you.