This is known to be a circuit that will have the ability to use high-speed connection so that different forms of media can be transmitted in a fast amount of time. Take note that although it seems fast, there are more advanced connections that are available right now. Some can even triple the amount of speed that T3 can provide.
In other words, this is a baseline internet connection. Anything that is slower than this will not be able to provide the needed data immediately. This can make people cranky and impatient especially if they need the information that they are trying to access the internet soon.