Google Cloud: Your cloud network, your way
In Premium Tier, inbound traffic from your end user to your application in Google Cloud enters Google’s private, high-performance network at the POP closest to your end user, and GCP delivers this traffic to your application over its private network.
Outbound and Inbound traffic delivery
Similarly, GCP delivers outbound traffic from your application to end users on Google’s network and exits at the POP closest to them, wherever the end users are across the globe. Thus, most of this traffic reaches its destination with a single hop to the end user’s ISP, so it enjoys minimum congestion and maximum performance.
We architected the Google network to be highly redundant, to ensure high availability for your applications. There are at least three independent paths (N+2 redundancy) between any two locations on the Google network, helping ensure that traffic continues to flow between these two locations even in the event of a disruption. As a result, with Premium Tier, your traffic is unaffected by a single fiber cut. In many situations, traffic can flow to and from your application without interruption even with two simultaneous fiber cuts.
GCP customers use Global Load Balancing, another Premium Tier feature, extensively. You not only get the management simplicity of a single anycast IPv4 or IPv6 Virtual IP (VIP), but can also expand seamlessly across regions, and overflow or fail over to other regions.
Read the entire article here, Your cloud network, your way
via the fine folks at Google Cloud