Various factors should play a role in your choice of a CDN. Getting the best deal for your money should be in your best interest, so here are a few things you need to keep in mind when talking with the CDN service providers:
Your Bandwidth Needs
How much bandwidth do you use monthly? Will you need 60GB a month or 60TB a month? When you purchase a CDN, you will be charged by the amount of GB are transferred. So if you’re only delivering small traffic amounts, you may not need a CDN. All you would need to do is switch your current web host to a dedicated environment, rather than a shared environment. Even a business class host would be a great option. Besides, it doesn’t seem plausible to pay thousands of dollars to a Tier 1 CDN if you only deliver 4 videos a year.
Performance is Everything
Having great network performance is essential for delivering satisfaction to the traffic coming to your website. You must be careful when choosing a CDN because all will claim that they offer the best network. There are three types of CDNs, Internet Based, Peer to Peer (P2P) and Peering/Private based. Akamai, so far, is the only Internet based CDN. It also has thousands of servers located all over. This can route traffic from 1 PoP to another, thus getting to the ISP the end user is connected to.
With the peering/private CDN, the server has regionalized PoPs around the globe. This is when the Pops are peered or directly connected with a lot of ISPs and backbones (as many as possible). Then once a request is sent from the end user to view a piece of content, the file is transferred to the end user from the CDN, bypassing the Internet altogether. P2P is different than the other two; with this, everyone who views the content acts as a PoP — the content is replicated all over the world. There really isn’t an infrastructure for Peer 2 Peer; the content can be accessed on any ISP around the world. You should be careful dealing with P2P because your content can and will end up on hundreds or even thousands of computers (you’ll have no control over the content then).
Technology and Support
It is important that you ensure that the CDN you decide to go with supports the technology that you are using. Yes, the CDNs deliver content thorough HTTP Progressive download, but it may not support true Flash Streaming (RTMP), Quicktime, Real Media or Windows Media Streaming (MMS, RTSP). Also, if you’ll be using MP3 Live, will the CDN support it? All of this you need to keep in mind along your search for a CDN. The quality of the analytics should be high enough for your needs and easy to use. Some like CDNs that show the amount of requests that have been made per object.
Now, the support offered with the CDN service is highly important. You don’t want to get caught being on hold for hours and hours just to get disconnected. Then you want to have access to knowledgeable customer service reps that are able to help you. What are the hours and days of operation?
Cost, Contract and Longevity
What type of contract are you looking for and what does the CDN you’re considering offer? The available contract options include month-to-month, six-month and annual. Before picking up a CDN service, find out how long they’d been in business. Are they a venture that’s capitally funded and are they in debt? The cost of the CDN should be reasonable and within your budget, of course, so check around for the best rates before signing any contracts.