Glossary

TEI (Terminal Endpoint Identifier) ‹ The Terminal Endpoint Identifier is used to identify a specific piece of equipment on an ISDN con- nection.

Telco ‹ Telco is a popular abbreviation for telephone company. The RBOCs are a subset of all telcos.

T Interface ‹ The interface point between the user premises network termination (NT1) and a switching or concentration point (NT2) such as PBX.

Tx ‹ Abbreviation meaning transmit, transmitter, or transmission.

U Interface ‹ The interface point between the user premises network termination (NT1) and the local digital exchange.

UNI ‹ See user to network interface.

User to network interface (UNI) ‹ The interface between the ATM end system (user) and the ATM network.

V.11 ‹ International interface recommendation electrically similar to RS-422.

V.24 ‹ International interface recommendation that defines interchange circuits. Similar to and operationally compatible with RS-232. (See RS-232.)

V.25 ‹ International interface recommendation for dial lines.

V.25 bis ‹ International interface recommendation for dial lines that includes an auto-dial command and response language.

V.28 ‹ International interface recommendation that defines electrical characteristics for the interchange circuits defined by V.24. Similar to and operationally compatible with RS-232. (See RS-232.)

V.35 ‹ International recommendation for a wide-band interface modem.

VN3/VN4 ‹ VN3 and VN4 are the French ISDN standards.

WAN (Wide Area Network) ‹ A network spanning a large geographical area that provides communications among devices on a regional, national, or international basis.

Workstation networked computer typically reserved for end-user applications.

X.21 ‹ (Packet-switched networks) International recommendation that defines a physical interface for X.25, using a 15-pin connector equivalent to V.11.

216

Interphase Corporation