The Dzongkhag Network Upgrade Dilemma
A dzongkhag administration in eastern Bhutan is upgrading its network. The current setup uses a single 100 Mbps leased line shared by 120 staff across five departments. Users complain of slow access to the national e-government portal (hosted in Thimphu) and frequent timeouts during video conferences with the ministry. The IT officer proposes upgrading to a 1 Gbps fiber link, but the budget is limited. The dzongkhag also plans to introduce a new online public service portal that will serve citizens from 15 gewogs, many of whom access via mobile networks. The IT officer must decide between (a) upgrading the leased line to 500 Mbps and implementing QoS, or (b) keeping 100 Mbps but deploying a local cache server and optimizing traffic. The dzongkhag has 20% packet loss during peak hours (9 AM–11 AM and 2 PM–4 PM). The finance officer insists on a cost-benefit analysis before approving any upgrade.
1. Analyze the network symptoms and determine the most likely bottleneck. Justify your answer using the given data.
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The symptoms-slow access to a remote portal, timeouts during video conferencing, and 20% packet loss during specific peak hours-point to congestion on the leased line rather than a last-mile issue. The 100 Mbps link is shared by 120 staff; if each user averages even 1 Mbps during peak, that saturates the link. Packet loss during peak hours indicates buffer overflow at the router or ISP shaping. Video conferencing is sensitive to latency and jitter; timeouts suggest queuing delays. The fact that issues occur only during peak hours (9–11 AM and 2–4 PM) reinforces that the bottleneck is the shared uplink capacity, not the local LAN or the portal itself. A local cache server could help for static content from the portal, but video conferencing and interactive services require sufficient bandwidth and QoS. Therefore, the primary bottleneck is the 100 Mbps leased line capacity, compounded by lack of QoS. Upgrading to 500 Mbps with QoS would address both capacity and prioritization, while caching alone would not solve real-time traffic issues.
2. Evaluate the two proposed options (a) and (b) from technical and financial perspectives. Which would you recommend and why?
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Option (a): Upgrade to 500 Mbps and implement QoS. Technically, this directly addresses the capacity bottleneck. QoS can prioritize video conferencing and interactive portal traffic over bulk downloads. Financially, it requires higher recurring lease costs, but may be justified if the dzongkhag's services depend on reliable connectivity. Option (b): Keep 100 Mbps, deploy local cache and optimize traffic. Caching can reduce redundant downloads of static content (e.g., e-government portal pages, updates), potentially cutting bandwidth usage by 30–50% if many users access the same content. Traffic optimization (e.g., compression, blocking non-essential streaming) can further reduce load. However, caching does not help with real-time video or dynamic transactions, and 100 Mbps may still be insufficient during peak. A hybrid approach might be best: implement caching and optimization first (lower cost), monitor whether packet loss and timeouts persist, and if they do, upgrade to 500 Mbps with QoS. Given the limited budget and the finance officer's insistence on cost-benefit, I would recommend a phased approach: start with option (b) for 3 months while measuring performance; if issues remain, proceed to option (a). This balances cost and service quality.