VLAN Assistance

[jonaskiwia]

I am currently managing a small WISP and our network is very basic but growing fast. I have purchased netonix switches for my tower and HQ. I tried viewing the video on VLANs you have on youtube and also going through the forum. But i'm not getting the exact idea of how to setup. I have therefore spent a lot of time in actually drawing my network with the idea of what I want to implement.
Basically below is how we have our devices and IP setup at the moment.
All Switches, Sector Antenna's, Client CPE's and PTP links are on 172.16.0.0/21 IP range, once the link is established at the customer's site we then configure his router with Static IP e.g 10.120.1.20/30 (10.120.1.21 configured on Mikrotik as gateway and 10.120.1.22 as customers IP)
The problem comes when customer wants to expand his network to branch offices and wants his HQ DHCP to give out IP's to branch office through my network, it messes up all my customers.
We therefore want to have separate VLAN's for such scenarios and also want to separate residence customers from corporate customers.
I will really appreciate if you could guide us step by step, from setting up the VLANs & Trunks on Mikrotik, Switches, Sector Port, and Client side CPE.
If there is any paid service available, we are also ready as long as our network improves.
I have attached my network setup, any assistance will be highly appreciated.
Thanking you in advance.

[slowe]

You could do this with vlans but I think its barking up the wrong tree. Best way would be a site to site VPN on the client side Firewall. There is a reason no other ISP does it via vlans

[sirhc]

I agree that is the wrong way to do it as VLANs mean a large flat network which is not in your future.
You do not want to give customers layer 2 access to your network.

You give them an IP they use a router and do a VPN with GR Tunnels if they want to simulate a single large layer 2 network but that also is dumb on their part, they want a different networks that route to each other across a VLAN