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When it comes to DNS, there's nothing we love more - except DNS management. And maybe Secondary DNS. Or Failover. Even anomaly detection. Oh who are we kidding, if it's even remotely close to the topic of DNS, we got you covered!
Since we launched our new traffic optimization service, ITO, we have received a lot of feedback from clients who want to know why they should use ITO over our traditional regional traffic director service. ITO is used to route users to the fastest responding server in their region. I bolded that for a reason. You really only want to use ITO when you have multiple endpoints in a region and you want users to be sent to the fastest one. If you use it on a global scale, with only one endpoint per region, you'll run into some problems. We'll elaborate on this in a minute. GTD (Global Traffic Director) splits up the world into five regions. Each region has its own zone file. So when a user wants the IP address of a domain, they will be answered by the zone file designated for their region. That means you can have different responses depending on the region. Now that you have a basic understanding of the two services, let's look at some use cases to illustrate the differences between the two and when you would want to use one over the over.Each numbered use case corresponds to a numbered flowchartin the diagram below.
You have two data centers, each hosting a copy of your website. This could be a basic sort of CDN that is managed with DNS. Or you are expanding into a new market and want faster load times.
You want users to be routed to the fastest responding data center.
Seattle, WA USALondon, GB UK
Users will always be routed to the fastest responding data center.
The average response times used to calculate which data center is the fastest is using a global average. This data is essentially irrelevant to the user because it is not specific enough to their location. Instead, we recommend only using ITO pools when you have more than one data center or server in a region. This way, all responses are optimized based on the region of the querying user.
Same as before, we have two data centers: one in London and one in Seattle.
You want users to be routed to the closest data center.
Users will be routed to a data center in their immediate region. In almost every case, this will also be the fastest responding data center. You also have backup data centers designated in the event that the primary is unreachable.
You have a large network with multiple servers in each region. Or you are building your own CDN with multiple web servers in each region. Or you want to manage a multi-CDN configuration.
You want users to be routed to the fastest responding server in their immediate region.
We’ll only use one region for this example, US East. Washington, DCChicago, IL
Users are always routed to the fastest responding server in their region.
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