Every time you stream a video, listen to a podcast, or view a page full of high-res images without any delays, buffers, or blips, you should thank a Content Delivery Network (CDN). CDNs like CloudFlare, Akamai, and Fastly make sure end users around the world can get content – video, audio, images, documents, and more – quickly and reliably. When you have a perfect, uninterrupted streaming experience, a CDN has done its thing. 

A CDN’s main goal is to reduce latency and improve the delivery speed of web content, such as images, videos, audio files, documents, and other resources. To do this, CDNs strategically position servers that house cached copies of content in multiple geographic locations. 

These locations, also called “points of presence” or “PoPs,” are usually chosen to be the shortest distance away from the largest numbers of end users. People using the CDN service get better performance because they don’t have to wait for a response from a server that is really far from them. 

And just how do providers ensure incoming requests get to the server that will deliver the highest performance? That’s where border gateway protocol (BGP) anycast comes in.

Maintaining a High Traffic, Global Infrastructure is an Ongoing Challenge

To be effective, CDN service providers have a lot to juggle. With globally distributed infrastructure, the larger the CDN, the more complex it becomes to manage. Providers must ensure every end user has a seamless, smooth experience, even when traffic is heavy. Some of the challenges include:

Speed and Latency

Choosing just the right location for geographically distributed servers can be real challenges, especially when traffic and usage constantly shift. Finding the right network and infrastructure providers in each location – and figuring out what each deployment needs – all requires careful and continual planning. Avoiding network congestion in every location is also a challenge, and one that increases exponentially as your footprint grows.

Scalability and Optimization

As a CDN becomes successful, usage will increase, often rapidly. As this demand changes and fluctuates over time, CDNs must keep a close eye on each location to make sure they aren’t under or overprovisioned. Overprovisioning can lead to excessive costs, and underprovisioning can lead to poor performance. Keeping the right balance requires a lot of time, energy, and effort.

Security and DDoS Mitigation

Few things are a greater threat to a CDN than a Distributed Denial of Service (DDoS) attack. They are becoming increasingly common as well – a recent report from StormWall saw a 47% year over year increase. A DDoS attack can easily knock out one or more locations, causing major performance issues or even outages. CDN providers need to take security very seriously, and invest in real-time threat response, advanced traffic filtering, anomaly detection, and more to ensure their services are available and high performing.

Other challenges can include compliance and regional regulations, having to manage multiple, complex interconnectivity agreements, continuous monitoring, and more. Operating a CDN is no easy feat, and that’s why it’s important to incorporate the right technologies – including anycast – that can help address these challenges at multiple levels.

BGP Anycast Solves Many Challenges at the Network Level

The demand for fast, reliable content continues to grow, and end users are becoming increasingly distributed as global markets mature. In turn, CDNs must continually evolve their infrastructure strategy to keep up. One part of the infrastructure stack that can’t be overlooked is Border Gateway Protocol (BGP) anycast.

BGP anycast is a technology that allows multiple, distributed PoPs to all “sit” behind a single IP address. Not only does this simplify the networking architecture, it routes incoming requests to the nearest, most performant location automatically. Every incoming request is sent to the location that has the most optimal routing path. Often, this correlates to the one that is geographically closest. 

You can learn more about how it works in this video from the Learn About Anycast and Networking channel:

The largest CDNs, like Akamai, CloudFlare, and Fastly, all leverage BGP anycast to keep their services fast and highly available to end users around the world. Other types of providers, such as those that rely heavily on DNS-based services, will leverage anycast routing to optimally direct traffic to their distributed DNS servers.

By incorporating BGP anycast at the network level, CDNs can get: 

The Lowest Possible Latency Every Time

With every location announcing the same IP address, users are automatically sent to the PoP that is the shortest number of “network hops” away. (When a user sends a request, every time it changes network segment, it is considered a hop.) This makes sure every user gets the best performance possible every time, even with a large global footprint.

Much Simpler Scalability

Because the IP address stays the same, it’s easier to add locations as your traffic grows. You can even add more locations in a similar region, and users will still get automatically routed to the best performing one for them. This automatically distributes the load across multiple nodes so no single location gets overloaded. This often allows providers to avoid the need for external load balancers, simplifying their infrastructure.

Built-in Redundancy and Failover

BGP anycast also makes redundancy and failover much easier. If one PoP goes offline or otherwise becomes available for any reason, traffic is simply rerouted automatically to the next closest location. For CDNs, this can really minimize the risk of a service interruption. If you have multiple locations within a region, users may not ever notice if one of those locations goes offline.

A Hedge Against DDoS, Congestion, and Other Issues

Because BGP anycast automatically distributes traffic to the closest location, it allows CDNs to minimize the impact of a DDoS attack. If a PoP is being targeted, incoming requests can be dynamically redirected away to the next nearest location, with no interruption in service. Anycast can also intelligently route traffic if there is congestion or other localized network issues.

Easier Network and Infrastructure Management

When BGP anycast is part of a CDN’s infrastructure strategy, it makes network management much easier. Because of its dynamic routing capabilities, no one needs to make any configuration changes manually. It also makes adding, removing, and maintaining PoPs simpler, as every incoming request is automatically routed based on performance, not other factors.

With more and more content being delivered online every day, CDNs face numerous challenges making sure every end user has a smooth, seamless experience. One way to address many of these challenges is by incorporating BGP anycast into your infrastructure strategy. It ensures high performance and availability, while protecting against DDoS, network congestion, and other issues that come up when dealing with a large, global footprint. Anycast also simplifies infrastructure and network management, and makes disaster recovery and failover much easier.

NetActuate’s network of worldwide data centers put it in a unique position of supporting some of the largest CDN providers in the industry. You can easily deploy applications on VMs, bare metal, or bring your own servers for colocation. Schedule a call with the engineering team to discuss a 30-day proof of concept for your application at netactuate.com.