What caused the sudden spike in latency for Infobip's Voice calls in the APAC region yesterday?

Introduction

The sudden spike in latency for Infobip's Voice calls in the APAC region yesterday is a critical issue that demands immediate attention and thorough analysis. As we delve into this problem, we'll employ a systematic approach to identify, validate, and address the root cause while considering both short-term fixes and long-term strategic implications.

Step 1

Clarifying Questions (3 minutes)

• Looking at the regional specificity, I'm wondering about network infrastructure. Has there been any recent changes to our APAC network topology or CDN providers?

Why it matters: Network changes could directly impact latency. Expected answer: No recent changes, but possible unplanned outages. Impact on approach: If confirmed, we'd focus on network stability and redundancy.

• Considering the suddenness of the spike, I'm curious about traffic patterns. Have we seen any unusual spikes in call volume or user behavior in the APAC region?

Why it matters: Unexpected traffic surges could overwhelm systems. Expected answer: Slight increase, but within normal range. Impact on approach: If confirmed, we'd investigate capacity planning and load balancing.

• Thinking about system dependencies, I'm interested in any recent updates. Have there been any software deployments or configuration changes in the last 48 hours?

Why it matters: Recent changes are often culprits in sudden performance issues. Expected answer: Minor update to call routing algorithm. Impact on approach: If confirmed, we'd scrutinize the update and its impact.

• Reflecting on monitoring systems, I'm concerned about data accuracy. Can we confirm that our latency measurement tools are functioning correctly and consistently?

Why it matters: Ensures we're addressing a real issue, not a monitoring anomaly. Expected answer: Monitoring systems verified and operational. Impact on approach: If issues found, we'd need to reassess the severity of the problem.