Difficulty: Medium
Correct Answer: a and b both
Explanation:
Introduction / Context:
Gateways that connect private enterprise networks to public carriers must allow authorized devices to reach public services while giving administrators the tools to manage access, usage, and expenses. The design focus is on controlled, universal reachability and accountable use—not necessarily on readdressing internal endpoints.
Given Data / Assumptions:
Concept / Approach:
Two fundamental needs are: (1) universal accessibility for approved DTEs—ensuring endpoints can reach required external destinations subject to policy—and (2) adequate cost control mechanisms, such as metering, accounting, quotas, and policy enforcement. Address assignment for private DTEs is typically an internal function (e.g., DHCP), not a public gateway obligation, though gateways may perform translation (e.g., NAT) rather than assignment.
Step-by-Step Solution:
Verification / Alternative check:
Real-world deployments include firewalls, NAT/ALG, AAA integration, and usage logging—features aligned with accessibility plus cost/usage control, not device address assignment.
Why Other Options Are Wrong:
Common Pitfalls:
Confusing NAT (translation) with DHCP (assignment), and assuming public gateways must manage internal address plans.
Final Answer:
a and b both.
Discussion & Comments