I need some one expert in ns3 to add routing metric

I already finish the work and my project did not have any errors, but my routing protocol did not get the path based on thats metric. I Already did the process to measure link quality by probing periodic packets. But its not measured the delay as expected. If any one have experiance to solve the problem please help me.

VPN network design

I have 3 offices that need to communicate via VPN. Some of the services use netbios. A layer 2 solution would probably be the easiest for me. All 3 offices need to communicate with a Google cloud PBX, which will also need to be VPN'ed. The google cloud instance is Debian linux. The offices are Windows 7,10,2012,2016,2019 environments over cable modems. I'm looking for a solid design that will allow me to have essentially one network to manage so I can centralize resources. I'm on a budget, so I don't want to purchase multi-thousand dollar Cisco or Juniper devices, etc. They are all small, 2 or 3 person offices. I'm looking for an encrypted VPN design approach, including equipment I might need to purchase, etc. Looking for bids on the detailed design.