The Cable Center

This glossary of cable and telecommunications terms is intended to enhance your understanding of this dynamic industry. We are able to present this information with the generous help of CableLabs - consult their website for the most up-to-date information about cable technology.

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10Base-T
One of the more common types of Ethernet Local Area Networking (LAN) cabling. Specifies 10 Mbps (baseband) carried over twisted pair.

100Base-T
One of the more common types of Ethernet Local Area Networking (LAN) cabling. Specifies 100 Mbps (baseband) carried over twisted pair. Also known as Fast Ethernet.

1000Base-T
One of the more common types of Ethernet Local Area Networking (LAN) cabling. Specifies 1000 Mbps (baseband) carried over twisted pair. Also known as Gigabit Ethernet or GigE.

2B1Q
Short for 2 Binary, 1 Quartinary. 2B1Q is a full-duplex digital signaling technique used by many digital communications technologies (like ISDN) to send data over a single pair of wires. It uses a system of three different voltages: one for each of the two binary states (the 2B part of “2B1Q”) and a third, quartinary voltage that indicates both ends of the data connection are sending the same binary value.

56Kbps Modems
More appropriately called Pulse Code Modulation (PCM) Modems, these modems manipulate the way the telephone system works to send data to an analog “modem” type device at speeds of up to 56,000 bits per second (56Kbps). 56K modems work by using ISDN telephone equipment at one end of the connection to manipulate the PCM codes sent across the telephone network. When these PCM sample codes reach the Codec they are translated into a specific series of voltage changes that a PCM modem knows how to interpret. Data sent out by a 56Kbps modem is subject to the same physical restrictions of any modem, so its top “back channel” speed is 33.6Kbps. 56Kbps modems are built against the ITU-T V.90 or V.92 standards.

5C
Refers to the five founding companies of the Digital Transmission Content Protection (DTCP) technology. Sony, Matsushita, Intel, Toshiba and Hitachi. Also used to refer to 5C digital certificates.

5ESS
A telephone company central office switch manufactured by Lucent Technology (an AT&T spin-off company) which has ISDN and other digital telephony capabilities. Frequently abbreviated to 5E. See also DMS-100.