23 U

U

Rack Unit

In its strictest sense, a rack unit (U) is a unit of measure that describes the height of a component mounted in a standard 19-inch rack. One rack unit (1U) is 44.45 mm (1.75 in) high. In this example, a “standard 44U frame” refers to the amount of vertical space occupied by this 19 inch-wide frame, which is 77.0 (1.75 inches x 44) inches high.

UA

ETF User Adaptation Layers

User Agent

UAA

User Authorization Answer (Diameter Cx)

UAC

User Agent Client

UAL

User Application Layer

UAM

Unsolicited Alarm Message

A message sent to a user interface whenever there is a fault that is service-affecting or when a previous problem is corrected. Each message has a trouble code and text associated with the trouble condition.

UAPS

UA Parameter Set

UAR

User Authorization Request (Diameter Cx)

UART

Universal Asynchronous Receiver Transmitter

UAS

User Agent Server

UBA

Unblocked Acknowledgement

UCIC

Unequipped Circuit Identification Code

Unidentified Circuit Identification Code

UCP

Universal Computer Protocol

Protocol used to connect to SMSCs.

UCS-2

2-byte Universal Character Set

UCS-2 coded SMS contains a maximum of 70 characters. It is in use in countries that needs more then the standard 7/8 bit to code their character set. Each character is represented by 2 bytes.

UDA

User-Data-Answer

Sent by a server in response to the User-Data-Request command.

UDM

User Defined Messages

UDP

User Datagram Protocol

UDR

User Data Repository. A logical entity containing user data.

User-Data-Request. A user-identity and service indication sent by a Diameter client to a Diameter server to request user data.

UDRBE

UDR Back End

UDRFE

UDR Front End

UDSA

User Defined Stop Action

UDT

Unitdata Transfer

UDTS

Unitdata Transfer Service

An error response to a UDT message.

UE

User Equipment

UG

User Guide

UHC

Upgrade Health Check

UI

User Interface

UIAS

User Interface Application Side

UID

User ID

UIM

Unsolicited Information Message. A message sent to a user interface whenever there is a fault that is not serviceaffecting or when a previous problem is corrected. Each message has a trouble code and text associated with the trouble condition.

Unified Inventory Management

UIMRD

UIM Redirect

UIS

User In Service

UISC

User Interface Session Control

UITS

User Interface Terminal Side

UL

Underwriters Laboratories

ULA

Update Location Answer

ULP

Upper Layer Protocol

ULR

Update Location Request

UMA

Unlicensed Mobile Access

A technology comparable with the activities of IEEE 802.21. UMA supports roaming and handover between cellular networks, GSM, GPRS, Bluetooth, and 802.11 type WLANs. UMA vendors do not guarantee interoperability.

UMTS

Universal Mobile Telecommunications System

The standard for 3G used by GSM service providers. UMTS includes voice and audio services, for fast data, graphic and text transmissions, along with transmission of moving images and video.

Unchannelized E1

Synchronous E1 High Speed Link

Unchannelized T1

Synchronous T1 High Speed Link

UNI

User-Network Interface

Unique Connection

A connection established that can be deterministically mapped to a Diameter configured connection.

Universal License Key

A license key that works on any OAP. This key is not dependant on the unique host ID of the machine.

UNKN

FNAI class Unknown

Unsolicited Alarm Message (UAM)

See UAM

Unsolicited Information Message

See UIM

Untrusted Network

A Diameter network which has topology information hidden by the Topology Hiding features.

UOS

User Out of Service

UPA

UltraSPARC Port Architecture

User Part Available

UPD

Update

User Datagram Protocol. The User Datagram Protocol is one of the core protocols of the Internet protocol suite. Using UDP, programs on networked computers can send short messages sometimes known as datagrams to one another.

Upgrade

A stage in the lifecycle of a Virtual Network Function (VNF) or a network service (NS) that updates, upgrades, or maintains the VNF or service (support VNF software and/or configuration changes of various complexity).

UPL

User Program Layer

Uplink Set

A pair of egress fabric links used to connect the T5100 platform with the customer. The pair functions as an active/backup high-availability link.

UPLU

User Program Layer Utilities

Upstream

The direction of a particular Diameter message from the Diameter client toward the home server.

Upstream Peer

Diameter Node to which Request messages are forwarded.

UPT

User Part Test

UPU

User Part Unavailable

An MTP3 management message.

URI

Uniform Resource Identifier

An internet protocol element consisting of a short string of characters that conform to a certain syntax. The string comprises a name or address that can be used to refer to a resource.

URK

Unregistered Routing Key

URL

Uniform Resource Locator

USB

Universal Serial Bus

USB Port

Receptacle for flash memory drives on personal computers. On the E5-MDAL card, a flush-mounted USB port used with credit card flash memory drives for upgrade. On the E5-MCAP card, a latched USB port for use with flash memory ”thumb” drives for installation and backup of customer data.

U-SBR

Universal SBR

USDA

User Defined Stop Action

User-Configurable Parameter

A user-configurable parameter is a configuration parameter that can be modified by the operator using a standard user interface. In general, when a user-configurable parameter is modified, the configuration change will take effect immediately without restarting the software, unless specified otherwise.

User Datagram Protocol

The User Datagram Protocol is one of the core protocols of the Internet protocol suite. Using UDP, programs on networked computers can send short messages sometimes known as datagrams to one another.

User Data Repository

See UDR

User Local Time

Local time of a UE that is calculated as an offset from UTC for the location of a UE.

User Local Time Context

Indicates that user local time is to be applied to policy rules.

USIS

User-to-User Indicators

USL

User Systems Language

USM

User Security Management

USR

User-to-User information

USSD

Unstructured Supplementary Service Data

UTC

Coordinated Universal Time

UTF-8

Variable-length character encoding for Unicode that is backward-compatible with ASCII.

Utility

The application that is used by the factory for testing. This application has no use in the field.

UTP

Unit Test Plan

Untwisted Pair