TCP is a reliable stream-delivery, virtual circuit connection-oriented protocol that runs on top of IP. Telnet, FTP, and login use TCP connec- tions.

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 ◆ Internationalinterfacerecommendationelectricallysimilarto 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 ◆ Internationalinterfacerecommendationthatdefineselectrical 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.

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