Single-user performance tests run on a two-computer setup with the three-tier architecture.
Computer A runs the client tests, and computer B runs the service tier and the database to represent the server. During the test, a network throttling tool was used on computer A to simulate limited bandwidth and high latency on the connection to computer B. The different settings on the network throttling simulate high-speed ISDN and different connection speeds for a typical ADSL connection that ranged from 128 kilobits per second (kbps) up to 50 megabits per second (Mbps). During the test, lost packages and network errors that can occur in a real-world Internet connection were not simulated.
The latencies represent the "different" distances between the client and the server. 
> 0 ms represents both computers being located in the same building or on the same site.
> 10 ms represents a short-distance link within a small country, such as Denmark. For example, the latency from Copenhagen to Aarhus (191 mi or 307 km) is 9 ms.
> 30 ms represents a country/region in Western Europe, such as Germany, Switzerland, or France.
> 60 ms represents countries or regions such as Turkey or Greece.
> 90 ms represents a long distance between countries or regions, such as Denmark to the United States.
> 200-250 ms represents a very long distance between countries or regions, such as China
> 310-3400 ms represents a very very very long distance (packet world tour !) between countries or regions (such Australia)
By Microsoft System Engineers Team