The Range Summary report is designed to give a high level view of calls into and out of a group of phones.  If you have several locations, or groups of phones, all beginning with the same digits, you will be able to show calls into and out of all of them.

For example, if the Pittsburg office has phones that all start with 42, and the Orlando office has extensions that start with 43, we can use one range summary search for each office.

Here we are looking for calls into our Pittsburg office (extensions that begin with 42)

Here, we can search for outbound calls from our Orlando office (extensions that start with 43)

You can get more information by clicking on the "open in new window" link next to the number of calls.