MLS- and MLC-Model Telephones, 2Using Telephones

Intercom call

Outside call

Primary line

Secondary line

Standard phone

A call that is made using the [ Intercom ] button on an MLS- or MLC-model telephone, to call another system extension without tying up primary Centrex lines.

A call made from outside the Centrex system to an extension within the Centrex system, or from inside the Centrex system to a number outside the Centrex system. If your Centrex system uses a dial-out code (usually a “9”), you must dial it before you dial an outside telephone number.

The main Centrex line assigned to an extension, generally used to place and receive all calls for that extension. When a caller dials a phone number, the call rings immediately at the extension where the line is assigned as a primary line (unless line ringing is changed to let a user at another extension screen calls on the line). See also Secondary line.

A line assigned to an extension for call coverage purposes, generally with delayed or no ringing. When a call comes in on the line, it rings first at the extension where it is assigned as the primary line; only if there is no answer does it ring at the extension where it is a secondary line. See also Primary line.

An industry-standard touch-tone or rotary phone such as you might have in your home. Some standard phones include special feature buttons for frequently-used calling functions.

MLS- and MLC-Model Telephones

MLS-and MLC-model telephones have some buttons and indicators in common. Refer to pages 6-4and 6-5for an explanation of where they are and how they work. Call handling instructions for MLS- and MLC-model telephones and industry-standard phones begin on page 6-12.

Ringing Patterns and Dial Tones

Your Centrex system determines the ringing pattern you will generally hear when calls ring at your phone. (For example, there may be different ringing patterns for inside and outside calls.) If someone makes an intercom call to your phone, you will hear a ring and a beep (ring BEEP . . . ring BEEP . . . ring BEEP . . .).

When making most calls, you will hear the Centrex dial tone, indicating that you are connected with a Centrex line. (If you press [ Intercom ], you hear the intercom dial tone. See Appendix B for information on using the intercom button.)

6-2Using Telephones

II specifications

AT&T II, a pivotal case in the landscape of telecommunications regulation, emerged from the expansive antitrust actions against the American Telephone and Telegraph Company (AT&T). Following World War II, AT&T had established itself as a telecommunications behemoth, monopolizing the market. The ramifications of this dominance spurred a significant shift in regulatory measures, leading to the dissolution of the Bell System in 1984, which consisted of AT&T and its regional operating companies.

One key feature of AT&T II is its emphasis on promoting competition in the telecommunications sector. The court's decision aimed to dismantle the monopolistic practices that had stifled innovation and restricted consumer choice. By encouraging competition among various service providers, the ruling paved the way for an environment where new technologies could flourish.

The technologies that emerged post-AT&T II significantly transformed the telecommunications landscape. The introduction of new digital switching systems allowed for improved call quality and increased network efficiency. The evolution of fiber-optic technology also played a crucial role, enabling faster transmission speeds and greater data capacity. Moreover, innovative services, such as mobile telephony and broadband internet, proliferated as competition increased.

Another characteristic of AT&T II is its focus on accessibility and consumer protection. The ruling mandated that telecommunications services be available to a broader swath of the population, ensuring that underserved communities had access to essential communication services. This shift not only democratized access but also laid the groundwork for the modern internet revolution, fostering the growth of the digital economy.

The impact of AT&T II can also be seen in the regulatory frameworks that followed. The Federal Communications Commission (FCC) adopted policies aimed at enhancing market transparency and ensuring fair practices among competitors. These regulatory changes helped to create a more equitable playing field, allowing smaller companies to compete against established giants.

In summary, AT&T II marked a turning point in telecommunications history, characterized by a focus on competition, technological advancements, and consumer protection. The dissolution of AT&T's monopoly allowed for the rapid evolution of technology and services, ultimately benefiting consumers and fostering an environment ripe for innovation. This ruling not only redefined the telecommunications industry but also set a precedent for how markets are regulated in the United States.

AT&T II manual MLS- and MLC-Model Telephones, Ringing Patterns and Dial Tones, 2Using Telephones

Models: II