What is a CDN edge server?

An edge server within a CDN refers to a computer strategically positioned at the outermost periphery or “edge” of a network. It frequently acts as the intermediary between distinct networks, facilitating seamless connectivity. The primary objective of a CDN edge server is to store content in proximity to client machines that request it, resulting in decreased latency and enhanced page loading speed.

Functioning as an edge device, an edge server serves as a gateway into a network, alongside routers and routing switches. These edge devices are commonly deployed within Internet exchange points (IxPs) to enable interconnection and transit sharing among diverse networks.

How does an edge server work?

In a given network setup, various devices establish connections with each other following specific network patterns. When a network needs to connect to another network or the broader Internet, it requires a bridge to enable traffic flow between different locations. The hardware devices responsible for creating this bridge at the network’s edge are referred to as edge devices.

Networks are interconnected at the edge, typically seen in home or office networks where multiple devices like mobile phones or computers connect and disconnect through a hub-and-spoke network model. All these devices exist within the same local area network (LAN) and connect to a central router, which facilitates their communication with each other.

To establish a connection between two networks, the networks must be linked at some point. The device enabling the connection between networks is known as an edge device.

Consider a scenario where a computer in Network A needs to connect to a computer in Network B. The connection must traverse from Network A, across the network edge, and into the second network. This principle also applies to more complex scenarios, such as connecting across the Internet. The ability of networks to share data is dependent on the presence of edge devices between them.

When a connection needs to traverse the Internet, additional intermediary steps are involved between Network A and Network B. For simplicity, imagine each network as a circle, and the point where the circles touch represents the network edge. To move a connection across the Internet, it typically encounters multiple networks and passes through several network edge nodes. Generally, the farther the connection travels, the more networks it needs to traverse. It may pass through different Internet service providers and backbone infrastructure hardware before reaching its destination.

CDN (Content Delivery Network) providers strategically deploy servers in numerous locations, with particular emphasis on the edge points between different networks. These edge servers establish connections with multiple networks, enabling efficient and rapid traffic flow between them. Without a CDN, transit may follow a slower or more convoluted path from source to destination. In the worst-case scenarios, traffic may unnecessarily travel long distances, even when connecting to a device across the street, resulting in unnecessary delays. By placing edge servers in key locations, CDNs can swiftly deliver content to users within various networks. To learn more about the benefits of using a CDN, you can explore how CDN performance works.

What is the difference between an edge server and an origin server?

The origin server is the central web server that receives all Internet traffic when a web property does not utilize a content delivery network (CDN). When a website relies solely on an origin server without a CDN, every Internet request must travel back to the physical location of that server, regardless of the user’s location. Consequently, this leads to longer load times, especially for clients located far away from the server.

CDN edge servers, on the other hand, store and cache content in strategically positioned locations. By placing static assets like images, HTML, JavaScript files, and other content as close as possible to the user’s machine, an edge server cache significantly reduces the time it takes to load web resources. This distribution of content helps alleviate the load on one or more origin servers. However, origin servers remain crucial when employing a CDN, as they handle essential server-side tasks such as managing a database of hashed client credentials used for authentication. To learn more about Toffs CDN and its globally distributed edge servers, explore their services.