Analysing Google Cloud routing tiers
Back in 2017, Google Cloud launched a low-performance tier and effectively gave an option to their customers of “cheaper” bandwidth with slightly reduced performance. This page describes their network tiers in detail.
That page says - “Cost optimized: Traffic between the internet and VM instances in your VPC network is routed over the internet in general.”
Background For a while, I wanted to find out how this works. In network routing this concept is known as “hot potato routing Vs cold potato routing”.