In the past, we watched videos using physical mediums like DVDs and VHS tapes. Today, most of us rarely look for a DVD because streaming services are so prevalent. This prevalence has strained content providers’ network infrastructure and pushed companies to upgrade their network technology. As a result, content delivery networks have become more robust and prolific. What is the connection between video streaming and content delivery networks?
Content delivery networks (CDNs) improve streaming performance. A CDN cuts page load times by two-thirds or more, providing end-users with better performance. Improvements in latency enable content providers to offer more latency-dependent applications and web content to their users.
Content delivery networks enable these benefits by storing popular and latency-sensitive data closer to users. For example, the top shows on Netflix are handled by a CDN so that peak traffic doesn’t hurt user experience. By positioning edge points of presence (PoPs) and edge nodes closer to users, the CDN balances network loads, ensures content availability, and lowers latency. By breaking down the CDN’s components, we can understand how they help companies improve user experience.
Breaking Down CDN Architecture
In a classroom, effective teaching is impacted by the subject matter, classroom size, and resources available. For instance, by reducing classroom size, teachers can better focus on individual student needs. Similarly, CDN architecture is dependent on network size, network infrastructure, and the type of content delivered. The distribution of servers will depend on what your network needs to prioritize, such as speed, coverage, or other metrics.
Businesses that want to use a CDN have to choose between a consolidated or scattered network infrastructure. The consolidated network uses fewer, high-capacity servers, and the scattered network uses more, lower-capacity servers. If latency needs are very high, it is best to have servers placed as close to the user as possible, which favors a scattered network setup. In contrast, when delivering static content to a predictable amount of users, a consolidated network will work better while saving on server costs.
When we go deeper, we see that the nodes of a CDN have specialized purposes. A CDN may contain control nodes, storage nodes, delivery nodes, and origin servers. What is the job of these components?
- Origin servers are the source of your data. Content is either pushed or pulled from the origin servers and stored at edge nodes designed for delivery or storage.
- Control nodes are where management, routing, monitoring, and security tools reside. However, in some CDN architectures, the delivery or storage nodes may also have the capacity for security tools.
- Delivery nodes are the key to content delivery. Content providers can cut data transfer rates by two-thirds or more by positioning delivery edge nodes as close to the user as possible. These nodes work in conjunction with origin servers to receive or pull data as needed and then distribute it to their dedicated regions. Once the data goes to the edge node, there is no need to access the origin servers directly — increasing network security.
- Storage nodes add efficiency to the CDN in large networks. Instead of pinging the origin servers, delivery nodes can ping strategically placed storage nodes to improve latency and lower demand on the origin servers.
When linked together, these three nodes distribute the workload evenly, provide DDOS protection by reducing direct access to the origin server, and shorten the distance between users and your content.
Combine Optimal CDN Design With High Performing Hardware
Planning your infrastructure in a way that best serves your customers is just one part of a high-performing CDN. Well-informed hardware choices play a significant role in network reliability, performance, and cost control. CDN infrastructure may be globally distributed and requires hardware that can flex to the unique needs of each region and scale with ease.