Digital DID Technical Detail

New York City Telephones circa 1900

Businesses ran dedicated telephone lines to each others businesses in NYC. This made for an unsightly skyline. 

Later, common tie cables ran to various switch boards and only then to the customer. Cables went underground. The NYC skyline looked better.

Yet, today's analog business telephone service requires too many dedicated lines to each customer's premise.

Analog Service is "Shocking"!

Dialing an analog telephone number rings a telephone line connected to a specific analog port on your business telephone system. The system routes the call based solely on the pre-programmed route for the port that is rung. An analog line actually "shocks" the telephone systems with a 90 volt ringing current to get the telephone system to answer the call. Your home telephone works on this same principle.

This electrical shock is a rather primitive routing signal. Shock on lines 1,2 or 3 and the receptionist rings.  Shock on lines 4 or 5 and accounting rings. Shock on line 7 and the bosses phone rings. Thus, a company with many departments needs many individual groups of analog lines to handle call volume to all departments.

In the analog world, you buy specific quantities of lines to satisfy the peak call volume of each extension, device or department in your business. Analog lines do not share!

Digital Direct Dial Service is Efficient

Digital DID service does not shock the telephone system to make it answer. It transmits a specific routing code to the telephone system on any available channel. Digital service moves some of the telephone call switching decisions to the customer's premise.

With digital service, you buy enough channels to meet the aggregate peak call volume of all extensions, devices and department hunt groups at your business. Digital channels share!

Infotel Systems - Richmond, Virginia - Business Telephone Systems, Voice & Data Networks, Cabling, Carrier Services  804-266-6600