A carrier is the company you pay for your paging service. They control the antennas, satellites, broadcast, and computer systems that are used to send the messages to your pager. You may purchase your paging service from a reseller who represents several paging carriers. They resell the paging service, but are not actually the paging carrier. When setting up WebGate, you will need some information about the actual carrier that your pager is serviced by (see the installation part of the documentation for specifics).