Communication between Devops pipelines and Self hosted build agent

Question

When a DevOps organization/Pipelines and a self-hosted agent on a virtual machine (VM) in the cloud are in the same region, is the connection established via the private Microsoft backbone network?

https://learn.microsoft.com/en-us/azure/devops/pipelines/agents/linux-agent?view=azure-devops#im-running-a-firewall-and-my-code-is-in-azure-repos-what-urls-does-the-agent-need-to-communicate-with

https://learn.microsoft.com/en-us/azure/devops/pipelines/agents/agents?view=azure-devops&tabs=yaml%2Cbrowser#communication-with-azure-pipelines

https://learn.microsoft.com/en-us/azure/devops/organizations/security/allow-list-ip-url?view=azure-devops&tabs=IP-V4#outbound-connections