Choosing A CDN Provider: 4 Vital Factors To Look For

CDN, Content delivery network, or content distribution network, is a geographically distributed network of proxy servers and data centers. A good network must provide high performance and availability to end-users by distributing services appropriately. This helps every user worldwide, irrespective of the location, to view the same high-quality content without it taking forever to load. Thus, a content delivery network is a network of servers whose purpose is to deliver content quickly to users.

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What Do I Look Out For When Choosing A CDN?

CDNs are a great and highly reliable way to upgrade the accessibility of your applications or services to access a seamless internet connection. However, the process involved in picking the correct CDN provider is pretty much challenging. This article examines the factors to consider when evaluating CDN providers.

A good CDN provider should be able to offer these basic yet essential services.

1. Be faster than your original network provider
2. Always be reliable
3. Have the ability to deliver small files consistently
4. Be able to provide large payloads
5. Drastically reduce the rate of latency caused by geographical distance.

Apart from these basic features, to deliver small files consistently, which are expected from every CDS provider, below are four other things that should be considered:

DNS Response Time

A couple of CDN providers have very complex DNS setups that can drastically slow down performance. This often looks like a relatively fast wait time that gets offset by a slower DNS response time. As a result, last-mile and end-user DNS performance can differ from the tests run in the backbone. This is as a result of the fact that end-users are mostly reliant on the DNS resolvers of their Internet Service Providers (ISPs) or Public Resolvers.

On the other hand, backbone monitoring relies on resolvers that are incredibly close to the machine running the tests. There could be so many irregularities for enterprise customers and large broadcasters, and the provider might still be slow because a single CDN can be overloaded. Using a Multi-CDN delivery method is exceptionally dependable and very good for live streaming with large audiences. Smaller companies may find a single CDN inadequate if they wish to operate globally and experience difficulties. They should switch to a multi-CDN as it involves a combination of several CDNs in some cases from different providers.

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Connect Time

It is essential to properly review the differing connecting times to ensure that your CDN has excellent reliable network connectivity, low latency, and no packet loss. Furthermore, it is vital to make sure it does not get slower along the line, especially during peak hours, and that you are being routed to the correct network peering. For example, if an end-user is on Verizon FIOS, there is no reason to go through five different backbone networks because that CDN does not have direct peering with Verizon.

Wait Time

The Wait Time is a clear indicator for all forms of potential capacity issues and wrong configurations that may be located either within the provider's CDN network or your origin server. Wait time helps reveal whether your content is being served from the edge or if it is being fetched directly from your original server. You may be wondering why your content would not be available on edge because that is what you are paying for.

It is no news that CDNs deliver different performance levels for static assets that are considered 'hot' or requested over 100,000 times within the past hour as against others that are only asked a few times per hour. This is because CDNs are a shared environment, where popular assets need to be delivered the fastest.

Traceroutes

CDNs often use commercial geo-mapping databases to map their customers and direct them to the correct locations. However, a couple of times, customers are assigned incorrectly due to the wrong IP address. Therefore, it is essential to run traceroutes from monitoring to ensure that you are not mapped to the wrong place. For example, if you run a traceroute and discover that your CDN is sending requests to the United Kingdom from your home connection in Los Angeles, there is undoubtedly something going wrong.

You must include communicating regularly with your CDN provider and monitor their performance metrics against the origin at all times within your plans. Doing so will create a solid and symbiotic relationship between you and your provider, which will eventually benefit all parties in the long run.

Isabella Humphrey

Update 17 June 2021