Cisco Systems 78-11450-03 See Universal Broadband Router, See Clear channel DS3, GL-14

Glossary

U

UBR	See Universal Broadband Router.
Unchannelized DS3	See Clear channel DS3.
Unicast	A message sent to a single network destination. Compare with Broadcast and Multicast.
Universal	A Cisco Cable Modem Termination System (CMTS) and carrier-class router that provides broadband
Broadband Router	high-speed data, broadband entertainment, and IP telephony solutions over a coaxial cable network.
Utility Card	Another name used in the software screens for the Timing, Communication, and Control Plus (TCC+)
	card.

V

Virtual Private Network

VLAN

VoIP

VPN

VT-n

See VPN.

Virtual LAN. A group of devices on one or more LANs that are configured (using management software) so that they can communicate as if they were attached to the same wire, when in fact they are located on a number of different LAN segments. Because VLANs are based on logical instead of physical connections, they are extremely flexible.

Voice over IP. Voice over IP enables a router to carry voice traffic (for example, telephone calls and faxes) over an IP network.

Virtual private network. A secure, end-to-end private network constructed over a third-party or public network such as the Internet.

Virtual tributary level n. The SONET format for mapping a lower-rate signal into a SONET payload. For example, VT-1.5 is used to transport a DS1 signal. See also DS1 and SONET.

W

WAN	Wide-area network. A data communications network that serves users across a broad geographic area
	and often uses transmission devices provided by a common carrier (such as a telephone company or
	service provider).

Weighted Fair

Queuing

Weighted Random Early Detection

WFQ

See WFQ.

See WRED.

Weighted Fair Queuing. Congestion management algorithm that identifies conversations (in the form of traffic streams), separates packets that belong to each conversation, and ensures that capacity is shared fairly between these individual conversations. WFQ is an automatic way of stabilizing network behavior during congestion and results in better performance and fewer retransmissions.

	Cisco uBR10012 Universal Broadband Router Hardware Installation Guide
GL-14	78-11450-03 Rev.B0