Plain old telephone service
is the analog telephone line that leaves your house or business and consists of either four or eight wires.
The Central Office
Consists of the equipment that generates a dial tone, interprets the telephone number dialed, checks for special services and connects the incoming call to the next point.
local access transport area (LATA)
is a geographic area such as a large metropolitan area or part of a large state.
does not have a telephone number associated with it because it can carry hundreds of voice and data channels.
Modified Final Judgement
1984 Court’s ultimate ruling, required the divestiture or breakup of AT&T into separate companies. Allowed for competition in the telephone provider market.
local exchange carriers (LECs)
Another name for Local telephone companies
Interexchange Carriers (IECs or IXCs)
Another name for Long Distance Telephone Companies
Centrex (Central Office Exchange Service)
A service from local telephone companies in which up-to-date telephone facilities at the telephone company’s central local office are offered to business users.
Private branch exchange (PBX)
Large, computerized, self-contained telephone system that sits in a telephone room on a company’s premises. Handles all in-house calls and places calls onto outside telephone lines.
Private lines or tie lines
leased telephone lines that require no dialing. They are permanent connections between two specified points.
Telecommunications act of 1996
paved the way for any carrier to offer a local telephone service to home and businesses.
Competitive local exchange carriers (CLECs)
These were the providers that emerged from the Tel. Comm. act of 1996. They included IECs, cable television operators, small companies, and electric power companies.
Incumbent local exchange carriers (ILECs)
Existing local telephone companies before the Tel. Comm. act of 1996.
V.90 Modem Standard
First standard to appear that supported 56k dial-up modems.
V.92 Modem Standard
The upstream link supports connections up to 48 kbps. Can place calls on hold (call waiting).
Digital Subscriber Line (DSL)
Technology that allows existing twisted pair telephone lines to transmit multimedia materials and high-speed data.
Has a faster downstream transmission speed than its upstream speed.
The downstream transmission speed is equal to the upstream speed.
When no splitter is used to separate the DSL signal from the POTS signal.
ADSL (Asymmetric digital subscriber line)
Transmits the downstream data at a faster rate than the upstream rate.
A slower format compared to ADSL; also known as Universal DSL, G.Lite and splitterless DSL. Typical transmission speeds are in the 200 kbps range.
Very high data rate DSL2 (VDSL)
A very fast format 100-Mbps downstream and upstream, over a very short distance.
Rate-adaptive DSL (RADSL)
A format in which the transfer rate can vary depending on noise levels within the telephone line’s local loop.
high-speed communications service that allows high-speed access to wide area networks such as the Internet via a cable television connection.
All-digital connection that can transfer either voice or data at speeds up to 1.544 Mbps.
A packet-switched network that was designed for transmitting data over fixed lines.
Permanent Virtual Circuit (PVC)
The permanent connection that is necessary to transfer data between two endpoints.
Layer 2 Protocol
Protocols that are part of a network application and reside at the data link layer.
Commitment information rate (CIR)
Agreed parameters between a customer and a frame relay carrier. This is a type of LSA.
Service Level Agreement (LSA)
Agreement signed between a customer and a carrier before any virtual networks are established.
Allows a customer to exceed the committed information rate by a fixed amount for brief moments of time.
Asynchronous Transfer Model (ATM)
Very high speed packet switched service that is offered by a number of communication companies. A Business that wants to send data between two points at very high transfer rates might consider using this.
53-byte data packages sent through the Asynchronous Transfer Model (ATM)
Virtual Channel Connection (VCC)
Logical Connection required before ATMs can transfer any data. Must be created over a virtual path connection (VPC)
Virtual path connection (VPC)
A bundle of Virtual Channel Connections that have the same endpoints. Used for control signaling, network management and routing.
When a VCC transmits user-to-network control signaling.
When a VCC transmits network management and routing signals.
Class of Service
Definition of a type of traffic and the underlying technology that will support that type of traffic.
Constant Bit Rate (CBR)
Similar to a current telephone system leased line, CBR is the most expensive class of service. Delivers a high-speed continuous data stream that can be used with transmission-intensive applications.
Variable Bit Rate (VBR)
Used for real-time applications, the applications that use VBR send bursts of data, and the Asynchronous Transfer Model network guarantees that the VBR traffic is delivered on time.
Available Bit Rate (ABR)
Good for traffic that does not have to arrive in a certain amount of time, provides feedback that indicates if a part of the Asynchronous Transfer Model network is experiencing congestion.
Unspecified Bit Rate (UBR)
There are no promises to when the data may be sent, there is no congestion feedback as opposed to ABR. Transmission using UBR might not make it to the final destination. Least expensive service.
Computer Telephony Integration (CTI)
Combines traditional voice networks with modern computer networks.
Users utilize a single desktop application to send and receive e-mail, voice mail and faxes
Interactive Voice Response
When a customer calls a company, his or her telephone number is used to extract the customer’s records from a corporate database. The customer records are displayed on a service representative’s workstation as the representative answers the telephone.
Integrated Voice Recognition and Response
A user calling into a company telephone system provides some form of data by speaking into the telephone, and a database query is performed using this spoken information.
Third party call control
users have the ability to control a call, for example, set up a conference call without being a part of it.
PBX Graphical user Interface
GUI representing call hold, call transfer, and call conferencing and other telephone communications options.
users can specify telephone numbers that are allowed to get through. All other calls will be routed to an attendant or voice mailbox.
Customized Menuing Systems
The capability of interactive phone menu system. “If you would like to make a call press 1, if not press 2, press 4 to speak to the operator”
Convergence of real-time and non real time communication services such as telephony, instant messaging, video conferencing, speech recognition, voice mail, e-mail, etc.