CDN stands for "Content Delivery Network". CDN Access which is provided on our Pro, Business, and Enterprise plans, can in many cases provide a faster response to an API query from our network. As a TrueCNAM customer on a plan that supports CDN Access, you may use the CDN PoP (Point of Presence) address, or our regular non-CDN PoP addresses, depending on which you find to be better for you.
1. A user in Ireland, which is relatively "far" geographically from our closest PoP, and typically has ~75ms of RTT (Round Trip Time) latency to our server on the east coast in the US, will generally see the following:
- Queries on average will take 326ms to our api.truecnam.net PoP address
- Queries on average will take 156ms to our cdn-api.truecnam.net CDN PoP address
In this example, the CDN access will return responses to queries in less than 1/2 the time, and ~170ms faster on average. The consistency of latencies will also frequently be more uniform and less dispersed using CDN PoP addresses as well.
Why it's frequently faster
API queries to our CDN Access PoP is frequently faster because the CDN network we use has 52 PoP's worldwide that sit in front of our network, and are frequently "closer" to you on the internet. These CDN PoP's perform what is known as "Early SSL Termination" which frequently speeds up the amount of time your device or software needs negotiating an SSL (encrypted) connection.
A basic explanation of Early SSL Termination is that when an SSL connection occurs, it requires several transaction which go back-and-forth between you and the server you are connecting to. Longer latencies (delay) over the internet can cause these connections to take a longer amount of time to establish. Early SSL Termination causes the negotiation between you and the server to be pushed "closer" to you in many cases, reducing the delay in establishing the SSL connection. You can find some more detailed descriptions of Early SSL Termination here and here.
NOTE: While this is known as "Early SSL Termination", your queries are still encrypted all the way from you to our network.