ATM (Asynchronous Transfer Mode)

A standard which defines high-load, high-speed (1.544 Mbps through 1.2 Gbps), fixed-size packet (cell) switching with dynamic bandwidth allocation. ATM is also known as “fast packet”.

BRI (Basic Rate Interface) An ISDN service referred to as 2B+D. BRI provides two 64 Kbps digital channels to your desktop. It’s capable of simultaneously transmitting or receiving any digital signal – voice, video or data. ISDN Terminal Adapters replace modems as the customer-premise connection to this service, enabling you to make direct connections of data terminals and telephones. ISDN BRI can be used for a myriad of purposes from a standard desktop or laptop PC. Applications are similar to a modem, although there are some significant advantages for ISDN:

• 64kbps or 128kbps Internet connection, with 1-3 second dialup time
• Send/Receive faxes: Group 3 and Group 4 (64kbps digital)
• Concurrent Internet access and phone / fax usage
• Telephony with multiple phone numbers
• Point-to-point video conferencing

ISDN BRI is truly ideal for remote working (teleworking) since it gives access to most of the services available in an office such as telephony, fax, email and Internet. The faster dialup speeds, coupled with high throughput (when compared to a conventional modem) offers a more effective remote working environment.


IP (Internet Protocol)

The protocol used to transmit packets of data over the Internet and routing them to their destination. An industry standard, connectionless, best-effort packet switching protocol used as the network layer in the TCP/IP protocol suite.

ISDN (Integrated Services Digital Network)

ISDN, which stands for Integrated Services Digital Network, is a system of digital phone connections. This system allows data to be transmitted simultaneously across the world using end-to-end digital connectivity. It is a CCITT standard for a network that accommodates a variety of mixed digital-transmission services; the access channels are basic rate (144 Kbps) and primary rate (1.544 Mbps). Dialup is fast. ISDN calls typically dial and connect in 1 to 3 seconds. It's a multi-mode medium in that a "B" channel can carry data, voice, fax or video. It also concentrates calls where a PRI connection can deliver 30 concurrent calls through one cable, and a BRI delivers 2 calls through one cable.

PRI (Primary Rate Interface)

An ISDN service that operates at a rate of 1.544 Mbps. This service provides 23 B channels at 64 Kbps and one D channel at 64 Kbps. The system uses eight Kbps for framing bits. In Europe the service provides 30 B channels at 64 Kbps and one D channel at 64 Kbps, and uses 64 Kbps for framing bits. This service allows for simultaneous transmission over all B channels and the D channel.

T1

A digital carrier used to transmit a DS-1 formatted digital signal at 1.544 Mbps. A T1 carrier can transmit large volumes of information across great distances at high speeds at a (potentially) lower cost than that provided by traditional analog service. A T1 carrier uses time-division multiplexing to manipulate and move digital information. It consists of one 4-wire circuit providing 24 separate 64-Kbps logical channels; the aggregate data equals 1.544 Mbps.