PoPs in CDN: the more the better?

Coverage and efficiency of CDN (content delivery network) greatly depends on the number and quality of PoPs (points of presence). Let’s get insight into this aspect and find out whether PoP quantity equals connection quality.

What is a point of presence?

To understand that, we need to dig deeper and realize how Internet connection is established. Every computer that establishes connection to the Internet becomes a part of a network, no matter where you get access from – your home or office. At home, you can use a modem and dial a local number to access the network provided by your ISP (Internet Service Provider). At work, local area network (LAN) may be used, but you still will be using an ISP that the company has. Working with ISP you become a part of the network that can connect to a larger network.

The vast majority of large communications companies use their private dedicated backbones to establish connection between various regions. In every region, a company has a Point of Presence (PoP). This is a place for local users to access the organization’s network, sometimes via a local phone number or dedicated line. Note that there is no controlling network, instead, a few high-level networks are connected with each other via Network Access Points.

Access node or point of presence (POP) is a starting point for the fiber path to the user. A point of presence performs several functions:

1. It houses all active connection and transmission equipment from provider.
2. It manages all fiber terminations.
3. It contributes to simpler and faster interconnection between optical fibers and equipment.

Points of presence are usually located in special datacenters, or ground floors of existing buildings belonging to companies. The locations are connected through main network cables and are connected to active equipment. Other devices and equipment like Optical Distribution Racks (ODRs) and fiber guiding systems help in fiber management.

The role of PoPs in content delivery

Being a network of interconnected edge servers and the main server, content delivery network caches static website content (images, media, CSS, JavaScript) in multiple locations. Whenever a user accesses a website, he is guided to the closest edge server to reduce physical distance for the content to travel. That helps to boost loading times and minimize latency.

Therefore, CDN service is suitable for websites that have target audience spread over several regions, countries, or even continents. Point of presence is the place where an edge server with cached content is located. Does it mean that you should opt for a CDN with the highest number of PoPs?

Both yes and no. First and foremost, you should pay attention to the coverage of CDN network. The location of PoPs is the key factor. If you have target audience in Europe, Asia and Pacific regions, there’s no point in overpaying for edge servers placed in the North and South America. Analyze what regions you want to target and choose CDN hosting with corresponding coverage. Comparing similar CDN networks that comply with your demands you may prefer the one that offers a higher number of PoPs.