A point-of-presence, often referred to as a POP, is the physical location where two or more types of communication devices establish a connection. A traditional example of a point-of-presence is found with the local telephone switch, which acts as the connection facility between local telephone lines and long distance services. In recent years, the term has been applied to connection points between users and the Internet, as well as between users and wireless devices.
In all its incarnations, the point-of-presence supplies the necessary link that makes the exchange of communications functions possible. With a local telephone switch, the POP allows end users to initiate a telephone call, with the signal routing through the local phone switch and jumping onto the long distance link to that local switch. Thanks to the POP, the signal is able to reach its destination, where a return signal confirms the successful connection and allows voice communication to take place.
With the advent of the Internet, the point-of-presence came to be identified with switches and routers that allowed users to establish a connection to the World Wide Web. Using existing digital telephone technology, it was possible to create this link in much the same manner as establishing a standard telephone call. The difference was in the type of data that was converted and transferred through the POP. Over time, enhancements to technology have made it possible for a POP to handle increasingly high volumes of data, leading to the development of today’s high speed communications capabilities.
Along the way, the concept of a wireless point-of-presence came into being. Early wireless methods allowed mobile phone users to be able to communicate with facilities that were capable of translating a satellite or radio signal into a form that could be understood by a standard telephone switch. This made it possible for cell phone users to call people with landlines, and vice versa. The same general principal has expanded in recent years to allow innovations like Voice over Internet Protocol, which effectively converts a standard audio transmission into a data stream, then converts the stream back into a digital phone signal at a point-of-presence near the point of termination.
The typical setup for any type of point-of-presence will include a combination of routers, servers, frame relays, digital and analog aggregators, and different types of telephone switches, including wireless equipment. This combination makes it possible for all sorts of electronic signals to be received at the POP, converted into the proper format, then routed on to the point of termination. In order to accomplish this, even smaller communities are likely to have dozens if not hundreds of POPs in place, allowing users to enjoy everything from efficient local phone service to wireless international exchanges of voice and data.