Last weekend I was helping my niece research the history of telecommunications for a school paper. The following is my attempt to present some interesting historical facts in a way that would make even Kevin Bacon proud.
Alexander Graham Bell and his partner Gardiner Hubbard formed Bell Telephone Company in 1875. They formed the company after receiving a challenge issued in a memo from the company who was originally offered and declined the same telephone patent. Part of that company’s memo read, “… the idea of ‘telephone devices’ is idiotic, why would a person want to use this when he can send a messenger to our telegraph office and send a message to any large city in the United States?” By the way, the other company was Western Union.
It is amusing that Western Union is credited with deploying the first commercial manual telephone switching system for the public (PSTN) in the city of New Heaven, CT. This was of course after Alexander Bell obtained a controlling interest in the company. Very soon these PSTN systems spread rapidly to most major American cities creating new employment opportunities for telephone operators.
One of these cities was St. Louis, where a salesman by the name of Amon Strowger became upset at the telephone operators for keeping his line busy. He later found out that one of the operators was a competitor’s wife, who intentionally kept his lines busy while transferring his potential sales calls to her husband. Strowger developed the dial telephone to obviate the need for a manual operator within the system. Not far after, automated telecommunications switching systems such as the PABX began replacing manual systems.
Another automated system developed in the telecommunications field was the Automated Call Distributor, better known as the ACD. Continental Airlines contracted Rockwell Automation to develop the first ACD after being turned down by most major telephone providers because “there is no market for such a device”. Rockwell rolled out The Galaxy ACD, which resembled HAL 9000 from Space Odyssey with its various colored light bulbs, diodes and tacked on phones. The year was 1973… (decades later I had the privilege of using this system when I worked at Rockwell).
In 1973 Xerox developed the Ethernet. According to their patent filing the original Ethernet address had eight-bit destination and source address fields, unlike today’s MAC addresses. According to accepted software conventions, 16 bits after the destination and source address fields specify a “packet type.” Different protocols use disjoint sets of packet types to characterize the data carried in these packets, thereby allowing higher-level protocols to dictate the use of these packets.
A very common use of these packets in today’s networks is for Voice over IP and is controlled by higher-level protocols such as Session Initiation Protocol or SIP. Due to its properties of extensibility, flexibility (for more information click here to view my previous blog on this topic) and being light on the network, SIP is the defacto protocol for voice over IP. In fact IP providers have been using SIP to talk amongst their internal networks for several years and now have recently started offering it to us everyday consumers and businesses. One such SIP trunking product labeled as IP Flexible Reach is offered by AT &T which more than a century ago was better known as Bell Telephone Company.