Backbone tests run from nodes in the Synthetic Classic Portal. A node is a unique combination of a geographic location and network provider; for example, "FINLAND: Helsinki - TeliaSonera".
Synthetic Classic nodes are located in data centers around the world. You can select any combination of nodes to test response time and overall availability of your web applications. The more nodes on which you run a test, the more thorough and comprehensive the picture of the web application's performance will be.