Here is a list of all struct and union fields with links to the structures/unions they belong to:

### - u -

- ucf : H323GatekeeperURQ
- udpPorts : OpalManager
- UdpPrefix() : OpalTransportAddress
- UDPTL() : OpalFaxSession
- Uganda : OpalLineInterfaceDevice
- Ukraine : OpalLineInterfaceDevice
- Unallocated : IAX2IeCauseCode
- UnallocatedNumber : Q931
- Unavailable : SIPHandler
- UnCompressSubClass() : IAX2FullFrame
- Undefined : SDPCommonAttributes, RTPExtensionHeaderInfo
- undefType : IAX2Frame
- UnitedArabEmirates : OpalLineInterfaceDevice
- UnitedKingdom : OpalLineInterfaceDevice
- UnitedStates : OpalLineInterfaceDevice
- unkeyRadio : IAX2FullFrameSessionControl
- UnknownCauseIE : Q931
- UnknownCountry : OpalLineInterfaceDevice
- UnknownDirection : H323GatekeeperCall
- UnknownPlan : Q931
- UnknownType : Q931
- UnLockSinkTranscoder() : OpalMediaPatch
- Unregister() : SIPEndPoint, IAX2RegProcessor, IAX2EndPoint, H323RegisteredEndPoint
- UnregisterAll() : SIPEndPoint
- UnregisterCodecPlugins() : OpalPluginCodecManager
- Unregistered : IAX2IeCauseCode
- UnregisteredByGatekeeper : H323Gatekeeper
- UnregisteredError : IAX2EndPoint
- UnregisteredFailureUnknown : IAX2EndPoint
- UnregisteredLocally : H323Gatekeeper
- UnregistrationRejectReasonMask : H323Gatekeeper
- UnregistrationRequest() : H323GatekeeperListener, H323Gatekeeper
- Unsigned2String() : PluginCodec_Utilities
- Unsigned32 : OpalMediaOption::H245GenericInfo
- UnsignedInt : OpalMediaOption::H245GenericInfo
- UnsubcribeAll() : SIPEndPoint
- Unsubscribe() : SIPEndPoint
- Unsubscribed : SIPHandler
- Unsubscribing : SIPHandler
- Update() : SIPDialogContext, SIPHandlersList, OpalMediaFormat
- UpdateDescriptor() : H323PeerElement
- UpdateHandlerIndexes() : SIPEndPoint
- UpdateMediaFormat() : OpalMediaPatch::Sink, OpalMediaPatch, OpalMediaStreamPacing, OpalMediaStream, H323Capability
- UpdateMediaFormats() : OpalFramedTranscoder, OpalTranscoder, OpalVideoTranscoder, OpalPluginVideoTranscoder, OpalPluginStreamedAudioTranscoder, OpalPluginFramedAudioTranscoder
- updateMutex : OpalTranscoder
- UpdateOptions() : OpalPluginTranscoder
- UpdateParameters() : SIPMessageHandler, SIPSubscribeHandler, SIPRegisterHandler
- UpdateRemoteAddresses() : SIPConnection
- URIs : OpalConferenceState
- urj : H323GatekeeperURQ
- url : H323HTTPServiceControl
- urq : H323GatekeeperURQ
- Uruguay : OpalLineInterfaceDevice
- usage : H235Authenticator
- UsageContext : SIPURL
- UseAlternate() : H460_FeatureStd23
- usedBandwidth : H323GatekeeperServer
- useDeblocking : OpalLineMediaStream
- UseGatekeeper() : H323EndPoint
- UseGkAndEpIdentifiers() : H235Authenticator
- UseMediaPassThrough() : OpalMixerNode
- UseMediaSession() : OpalRTPConnection
- UserAdded : OpalConferenceState
- UserBusy : IAX2IeCauseCode, Q931
- userData : PluginLID_Definition, PluginCodec_Definition
- UserDefinedTone : OpalLineInterfaceDevice
- userIndex : IAX2EndPoint
- UserInformationMsg : Q931
- UserInput() : OpalMediaType
- userInputAvailable : OpalConnection
- UserInputMethodUnknown : SIPConnection
- userInputString : OpalConnection
- userName : IAX2RegProcessor, IAX2IeData, IAX2Connection, IAX2CallProcessor
- UserRemoved : OpalConferenceState
- Users : OpalConferenceState
- UseRTPSession() : OpalRFC2833Proto
- UserUserIE : Q931
- UsesRTP() : OpalLineInterfaceDevice
- usPerFrame : PluginCodec_Definition
- USSR : OpalLineInterfaceDevice
- UTF_NEWLINE : T140String
- uuiesRequested : H323Connection