How to forward N vlan through the operator's network?

Question

D-Link

Good afternoon.
The task is to forward the vlans through the operator's network at the ends of the network are D-Link 3200-28.
There are client ports on each side, how to accept vlans with any id on it and transfer it
through the network with one operator vlan-id?
vlan-id 100,200,300 port1/port25 -----vlan-id 400----- port25/port1 vlan-id 100,200,300
something like this, there is a port to which tagged vlans come, they are additionally marked with 400 and already as one vlan go through the operator's network (equipment is different) on the final port of the client acc. the operator tag is removed and given to the port
began to read, but more confused
I would be grateful for any advice, link
Thank you

Answer 1

QinQ technology, port 25 trunk vid 400, port 1 dot1q-tunnel, access. Further from port 1 catch them with tags.