Cloud Digital Leader Practice Question: An architect is evaluating trade-offs between…

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  Google's private backbone uses faster optical fiber than public internet service providers

  Why it's wrong here

  The claim that Google's backbone uses faster optical fiber is physically inaccurate: both Google and public ISPs deploy fiber-optic cables where the propagation speed of light is essentially constant. The measurable performance advantage stems from routing efficiency, not from exotic cable materials. Traffic on Google's private backbone traverses fewer hops, avoids internet peering bottlenecks, and benefits from sophisticated traffic engineering and congestion management, resulting in lower latency and higher throughput. In contrast, public internet routing often involves many autonomous systems with variable queueing delays and suboptimal paths.

• ✓

  Traffic on Google's private backbone avoids public internet congestion and variable routing, providing consistently lower latency and higher throughput for traffic between regions and to users near Google PoPs

  Why this is correct

  This correctly identifies the advantage. Public internet traffic traverses multiple autonomous systems with variable congestion. Google's backbone provides a direct, high-quality path between regions. Applications using Cloud CDN or global load balancers benefit from traffic entering Google's network early and staying on the backbone.

• ✗

  Google's private backbone is free for customers while public internet egress incurs data transfer charges

  Why it's wrong here

  Google's private backbone is not free; customers are billed for data transfer, including egress to the internet and inter-region traffic that stays on the backbone. For example, moving data from a VM in one region to a VM in another region incurs inter-region data transfer charges at a per-GB rate. Ingress traffic typically has no charge, but egress, especially over Premium Tier, carries a premium price. Thus, contrary to the option, the backbone itself is monetized, and using it can cost more than standard internet egress when traversing between distant regions.

• ✗

  Using Google's backbone eliminates the need for application-level TLS encryption because the network is inherently secure

  Why it's wrong here

  Google's private backbone protects data in transit with physical and network-layer security, but it does not absolve applications from needing TLS. TLS provides end-to-end encryption, authentication, and integrity that survive beyond Google's network, including on the public internet when data leaves the cloud. Even inside Google's infrastructure, insider threats, misconfigurations, and compromised services are risks that are best mitigated by application-level encryption. Moreover, TLS is also a compliance requirement for many regulated workloads, irrespective of the underlying network's trustworthiness.

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