What factors are contributing to the sudden 30% increase in latency for Zayo Group's Wavelengths service in the Northeast region this month?

Introduction

The sudden 30% increase in latency for Zayo Group's Wavelengths service in the Northeast region this month is a critical issue that demands immediate attention. As we dive into this analysis, we'll systematically identify potential root causes, validate our hypotheses, and develop a comprehensive plan to address the problem.

I'll approach this issue by first clarifying key details, ruling out external factors, and then diving deep into the product's user journey and metrics. We'll generate data-driven hypotheses, conduct a thorough root cause analysis, and propose validation methods and solutions. Throughout this process, we'll consider both short-term fixes and long-term strategic implications.

Step 1

Clarifying Questions (3 minutes)

• Looking at the timing, I'm thinking this could be related to recent network changes. Have there been any significant infrastructure updates or maintenance activities in the Northeast region in the past month?

Why it matters: Infrastructure changes often impact service performance. Expected answer: Yes, there was a major router upgrade. Impact on approach: If confirmed, we'd focus on post-upgrade configuration issues.

• Considering the specificity of the increase, I'm wondering about our measurement accuracy. Has there been any change in how we measure or report latency for the Wavelengths service?

Why it matters: Ensures we're addressing a real issue, not a measurement anomaly. Expected answer: No changes in measurement methods. Impact on approach: If there were changes, we'd need to validate the new measurement system.

• Given the regional nature of the issue, I'm curious about traffic patterns. Have we seen any unusual spikes in data traffic or changes in usage patterns specific to the Northeast region?

Why it matters: Helps identify if the issue is demand-driven or infrastructure-related. Expected answer: Normal traffic patterns with seasonal variations. Impact on approach: Unusual patterns would shift focus to capacity planning and load balancing.

• Considering potential external factors, I'm wondering about our peering agreements. Have there been any changes in our peering relationships or interconnection points in the Northeast?

Why it matters: Peering changes can significantly impact network performance. Expected answer: No major changes in peering agreements. Impact on approach: If changes occurred, we'd investigate the impact of new peering arrangements.