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Supercharging Streaming Media with Multi-CDN

Streaming media is everywhere, consumed by almost all of us at all times of the day.

Streaming media providers are required to deliver audio, video and other media at unprecedented scale, while ensuring a great user experience for users in all corners of the globe.

This page will help you understand:

  • The streaming media lifecycle
  • Common streaming media protocols
  • What affects the streaming media user experience
  • CDN and multi-CDN strategies for delivering streaming media
  • How multi-CDN improves the streaming experience
  • 4 more ways to improve performance and cost
  • How NS1 empowers multi-CDN with next-gen DNS

The single most important strategy for improving the streaming experience is a Content Delivery Network (CDN). Advanced providers are using multiple CDNs to combine their strengths, build in redundancy and failover into their workflows, and ensure each user gets an optimal experience. Learn how multi-CDN can supercharge the streaming media experience, and how next-generation traffic steering technology from NS1 can help you make the most of your multi-CDN investment.

What is Streaming Media?

Streaming is the transmission of rich media like audio and video files between servers, known as streaming servers, and clients such as desktop computers or mobile phones. It enables billions of users to consume podcasts, TV shows, user-generated videos, and even live events.

Before streaming technology, users had to download a media file in its entirety in order to view it. In a streaming model, the server transfers media to the client a few seconds at a time, allowing clients to access content much more quickly, without taking up local storage.

Video streaming cta

The Streaming Media Lifecycle

The streaming media lifecycle is composed of several stages:

1. Capturing video or audio content

2. Encoding the content into a format like MP4, MOV or AVI

3. Uploading the content to the streaming server

4. Processing the content on the streaming server

5. Delivering content to the user over the Internet

6. Playing content on the user’s client device

What is NS1?

NS1 provides active traffic steering across multiple CDNs, which helps streaming content providers ensure the best experience for each user.

Streaming Protocols: How Streaming Media Works

Streaming servers use a variety of protocols to stream media to client devices, each with different capabilities in terms of latency, streaming quality and reliability. Below are some of the more common streaming protocols.


Technical features


HTTP Live Streaming (HLS)

Developed by Apple, adjusts the bitrate of the media stream to client capabilities and bandwidth.

Video codecs: AAC-LC, HE-AAC+, MP3

Latency: up to 30 seconds

Buffering: Supports buffering but tries to avoid it by adjusting bitrate

Google Chrome, Android, Microsoft devices, all Apple devices, smart TVs


An open protocol developed by the MPEG organization. Dynamic streaming protocol over HTTP.

Video codecs: Works with any codec

Latency: up to 30 seconds

Buffering: Supports buffering but tries to avoid it by adjusting bitrate

Google Chrome, Android, smart TV, Safari, but not iOS devices.

RTMP Streaming

Designed by Adobe, originally used by the Flash Player, but still used today even as Flash is phased out.

Video codecs: H.264, VP8, VP6

Latency: 5 seconds

Buffering: None

Flash player, Adobe AIR and a small number of compatible players


A new protocol that enables real time communication (RTC) with very low latency, designed to support unified communications.

Video codecs: VP8, VP9

Latency: Under 500 milliseconds

Buffering: Supported

Google Chrome, Safari, Firefox. Other browsers can support the protocol via a plugin.

RTSP Streaming

UDP-based stateful protocol, mainly used to transfer media data. Does not support client-side commands.

Video codecs: AAC, HE-AAC+, MP3

Latency: 2 seconds

Buffering: None

Quicktime player, VideoLAN player, small number of compatible players.

There are also several efforts to develop low latency delivery formats to reduce end-to-end latency to less than three seconds.

Chunked encoding and transfer for CMAF (Common Media Application Format) breaks up a video segment into smaller chunks which can be immediately published upon encoding and transferred through a CDN to the player rather than buffering to wait for the full segment to complete. CMAF is a manifest independent and can be used for both HLS and DASH media presentation protocols.

Apple Low Latency HLS is an extension to HLS that uses shorter media chunks and mimics the chunk-transfer approach by using the tag #EXT-X-PRELOAD-HINT. Since the specification is still evolving, the requirements remain fluid and vendors implementing against it must adapt as it changes.

What Affects the Media Streaming User Experience?

Organizations managing streaming media go to great lengths to improve the user experience. The main parameter that determines stream performance is the streaming protocol. The diagram below shows common latencies for video streaming per use case and streaming protocol.

Within the performance boundaries of the protocol you select, the user experience will be determined by two groups of factors: network-related and user-related.

Network Related Problems

Network availability - infrastructure or operational issues that make a network path unavailable for some period of time

Network latency - the time takes for media to travel from server to the client across the network

Network congestion - current usage of the network path between streaming server and user

User Related Problems

Network bandwidth - available bandwidth on the end user’s device or nearby upstream networks (for example, local LAN and ISP)

Device capabilities and connectivity issues - the user’s local device performance and quality of its WiFi or wired connection often referred to as last-mile problems

CDN and Multi-CDN Strategies for Delivering Streaming Media

Content Delivery Networks (CDN) are considered a must for delivery of modern streaming media. A CDN is a group of Point of Presence (PoP) servers distributed around the world, allowing streaming providers to host media files near the physical location of end users.

CDNs can reduce streaming latency, improve reliability, and also distribute the load across multiple CDN servers. This removes much of the burden of scalability and high availability from the streaming provider to the CDN operator.

Many streaming media providers are adopting multi-CDN strategies. Combining several CDNs can be highly effective, because CDN performance can vary over time, and different CDNs have different strengths in terms of PoPs in specific geographical location, service features, and cost relative to performance.

Multi-CDN can provide the following benefits for streaming media:

  • Geographic distribution - when streaming to a global audience, it can be useful to divert specific audiences to CDNs that provide better support in their region.
  • Service features - different types of streaming content can be split between CDNs that provide specialized features, for example live events can be streamed on CDNs that support lower latency and high reliability.
  • Cost optimization - different CDNs offer different costs depending on volume, region, and other parameters.

How Does Multi-CDN Improve the Media Streaming User Experience?

A multi-CDN infrastructure can solve the network-related issues that affect streaming user experience:

  • Network availability - With a single CDN provider, any outages or operational issues immediately impact all users. Using multiple CDNs can minimize the impact of issues because users can be routed, or switched, to other CDNs until the problem is resolved, thus improving the resiliency of the media streaming service.
  • Network latency – A multi-CDN strategy can improve network latency in a number of ways. Some CDNs will have better PoP coverage in certain geographies than others, therefore using a combination of CDNs can bring the content closer to users in a wider range of geographies, resulting in lower latency for more users. Additionally, a CDN’s performance can vary significantly over time, therefore using a combination of CDNs enables streaming providers to dynamically route users to the best performing CDN at the time.
  • Network congestion – Multi-CDN infrastructure gives streaming media providers more options for handling network congestion issues and improving throughput than a single CDN. Distributing users across multiple CDNs ensures that the video and audio streams can be efficiently delivered during extreme spikes in user demand, such as the first minutes of a live event.

To address user-related issues affecting streaming experience, the streaming media provider would have to analyze metrics collected from the user’s local device and from CDNs to determine what actions, if any, could be taken to improve performance.

NS1 Steers Traffic to the Optimal CDN based on business logic

NS1 helps streaming service providers monitor multiple CDNs, identify issues, and use easily configurable routing policies to automatically steer users to the optimal CDN based on availability, latency, congestion and quality of user experience.

5 More Ways to Improve Performance and Cost

There are more ways streaming media providers can improve performance and reduce their CDN costs. Here are five of the most common methods, and how NS1 can help you implement them.


Allows you to “fence in” users from a specific geographical location. This can be used to direct users to a specific CDN that provides better service in their location. It can also be used to enforce rights management in different territories.

How NS1 Can Help

NS1 can perform geo-fencing based on accurate geolocation data, and can combine location with any other parameter such as type of content or user attributes.

CDN Performance Monitoring

Provides real-time analytics measuring how CDN are performing and their impact on user experience of video or audio streaming. This allows streaming providers to make data-driven decisions to improve performance.

How NS1 Can Help

NS1 automatically detects changing conditions across multiple CDNs and adjusts routing decisions to shield users from CDN

outages or localized network events.

User Quality of Experience (QoE) Monitoring

Provides real-time analytics collected from users’ local devices, which allows streaming providers to understand how last-mile issues impact user experience of video or audio streaming.

How NS1 Can Help

NS1 combines CDN performance data and third-party QoE data to select the best performing CDN for each user. It can route user requests to a CDN based on live quality of experience data.

Mid-Stream Switching

When users view long media streams or live events, performance can degrade at one or more points during the stream. Mid-streaming switching lets providers identify performance degradation and switch users in mid-stream to another CDN.

How NS1 Can Help

NS1 integrates with mid-stream switching processes by detecting problems with leading indicators, providing data comparing alternative CDNs, and providing a simple way to change CDN routing policies on-the-fly.

Dynamic Cost Optimization

For streaming providers, CDN can represent a major expense. CDNs have different costs, with varying pricing structures based on volume, region, and other parameters. It is inefficient to send all traffic to one CDN or split traffic evenly between CDNs. To optimize costs, you should dynamically select the CDN that will give users the best possible experience while conserving costs.

How NS1 Can Help

NS1 helps you distribute traffic smartly between CDNs to balance your cost and quality of experience goals. Avoid higher-priced CDNs when another provider can offer a similar experience at a lower price.

NS1 Empowers Streaming with Intelligent Traffic Steering Across Multiple CDNs

NS1 is the smart choice for video and audio streaming providers implementing a multi-CDN strategy. NS1 efficiently routes users to the best CDN based on geographical coverage, real-time performance analysis, and other business factors such as CDN commits or cost. Media providers have complete flexibility over which routing parameters and performance metrics are used, and how they are combined to make smart CDN selection decisions.

NS1 Advanced Traffic Routing for Multi CDN

Turnkey Performance-Based Steering

NS1’s Pulsar solves the problem of static load balancing between CDNs by using a real-time dynamic map of internet conditions across all major CDN for immediate performance-based routing.

Ns1 feature search inspect

Real User Monitoring

NS1’s Pulsar collects billions of metrics from actual users worldwide to provide insight into availability, latency, and throughput of each CDN in real-time. Based on this data, it can dynamically route each user to the CDN likely to provide users with the best experience.

Automatic Response to Network Disruptions

NS1 automatically detects changes in CDN availability, latency, and throughput and shields users from outages and localized network events by routing them to optimal alternatives.

Point-and-Click Configuration

NS1’s code-free configuration of traffic steering policies simplifies multi-CDN orchestration so streaming providers can guarantee optimal user experience while meeting business KPIs such as costs or usage commits.

Analyze Traffic Distribution

Validate you're getting the desired traffic distribution, with full visibility into user routing decisions.