Introduction

In this tutorial you will learn how to use client observability to monitor real-time quality metrics for a video call with the Vonage Video iOS SDK (Swift).

Client observability is the Vonage Video SDK feature that exposes stream-quality metrics on the device—packet loss, bytes sent or received, estimated bandwidth, network condition scores, and more—for any published or subscribed stream. Use it to debug calls, log quality trends, or show users actionable connection feedback while a session is live.

What You Will Build

An iOS app (Swift, SwiftUI) that joins a Vonage Video session and shows a semi-transparent stats overlay that updates as metrics arrive.

The goal is to show how your app can surface live call-quality data while a user is subscribed to a remote stream. You will implement OTSubscriberKitNetworkStatsDelegate on the subscriber, enable sender-side statistics on the publisher, and display the results in an on-screen overlay.

For conceptual information on the Video API, see the General overview.