Telephone Terminology U-Z

U

USOC – Universal Service Order Code. The Bell System Universal Service Ordering Code (USOC) system was developed to connect customer premises equipment to the public network. These codes, adopted in part by the FCC, Part 68, Subpart F, Section 68.502, are a series of Registered Jack (RJ) wiring configurations for telephone jacks that remain in use today. The now-famous RJ-11 and RJ-45 came from this naming convention.

V

Variant - The particular protocol (i.e. National ISDN-1 or ETS 300) running on a specific switch. Not all variants are valid for a specific switch. The switch brand and model plus the variant defines the ISND protocol. Applies to configuring the 2101. See ISDN Protocol.

Virtual ISDN - An alternative to repeaters that uses a local Telco Switch to act as a repeater and which then sends the signal onto another switch supporting ISDN. See also Repeater.

VoIP – Voice over Internet Protocol. Communications services that are transported via packet-switched IP networks rather than the public switched telephone network (PSTN).

W

Work Order - See Trouble Ticket.

Y

Yellow Alarm - An alarm on a T-carrier circuit that is returned by the local equipment if it is in a Red Alarm state. A Red Alarm indicates a loss of inbound signal; a Yellow alarm indicates (indirectly) a loss of outbound signal. See Red Alarm, Blue Alarm, and LOS.