[SOLVED] Communication between Devops pipelines and Self hosted build agent

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?

enter image description here

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

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

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

Based on my knowledge, the pipeline and self-hosted agent communicate through the public network, even if your organization and Azure VM are in the same region. According to this official doc Allowed IP addresses and domain URLs, there are only outbound connections and inbound connections used in different scenarios without any private network mentioned.