h323con.h

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/*
 * h323con.h
 *
 * H.323 protocol handler
 *
 * Open H323 Library
 *
 * Copyright (c) 1998-2001 Equivalence Pty. Ltd.
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 * the License for the specific language governing rights and limitations
 * under the License.
 *
 * The Original Code is Open H323 Library.
 *
 * The Initial Developer of the Original Code is Equivalence Pty. Ltd.
 *
 * Portions of this code were written with the assisance of funding from
 * Vovida Networks, Inc. http://www.vovida.com.
 *
 * Contributor(s): ______________________________________.
 *
 * $Revision: 23729 $
 * $Author: rjongbloed $
 * $Date: 2009-10-29 23:46:33 +0000 (Thu, 29 Oct 2009) $
 */

#ifndef OPAL_H323_H323CON_H
#define OPAL_H323_H323CON_H

#ifdef P_USE_PRAGMA
#pragma interface
#endif

#include <opal/buildopts.h>

#if OPAL_H323

#include <opal/rtpconn.h>
#include <opal/guid.h>
#include <opal/buildopts.h>
#include <h323/h323caps.h>
#include <ptclib/dtmf.h>


/* The following classes have forward references to avoid including the VERY
   large header files for H225 and H245. If an application requires access
   to the protocol classes they can include them, but for simple usage their
   inclusion can be avoided.
 */
class PPER_Stream;
class PASN_OctetString;

class H225_EndpointType;
class H225_TransportAddress;
class H225_ArrayOf_PASN_OctetString;
class H225_ProtocolIdentifier;
class H225_AdmissionRequest;
class H225_AdmissionConfirm;
class H225_AdmissionReject;
class H225_InfoRequestResponse;
class H225_DisengageRequest;
class H225_FeatureSet;

class H245_TerminalCapabilitySet;
class H245_TerminalCapabilitySetReject;
class H245_OpenLogicalChannel;
class H245_OpenLogicalChannelAck;
class H245_TransportAddress;
class H245_UserInputIndication;
class H245_RequestMode;
class H245_RequestModeAck;
class H245_RequestModeReject;
class H245_ModeDescription;
class H245_ArrayOf_ModeDescription;
class H245_SendTerminalCapabilitySet;
class H245_MultiplexCapability;
class H245_FlowControlCommand;
class H245_MiscellaneousCommand;
class H245_MiscellaneousIndication;
class H245_JitterIndication;

class H323SignalPDU;
class H323ControlPDU;
class H323EndPoint;
class H323TransportAddress;

class H235Authenticators;

class H245NegMasterSlaveDetermination;
class H245NegTerminalCapabilitySet;
class H245NegLogicalChannels;
class H245NegRequestMode;
class H245NegRoundTripDelay;

class H450xDispatcher;
class H4502Handler;
class H4504Handler;
class H4506Handler;
class H4507Handler;
class H45011Handler;

class OpalCall;

#if OPAL_H460
class H460_FeatureSet;
#endif



class H323Connection : public OpalRTPConnection
{
  PCLASSINFO(H323Connection, OpalRTPConnection);

  public:
    H323Connection(
      OpalCall & call,                         
      H323EndPoint & endpoint,                 
      const PString & token,                   
      const PString & alias,                   
      const H323TransportAddress & address,    
      unsigned options = 0,                    
      OpalConnection::StringOptions * stringOptions = NULL 
    );

    ~H323Connection();

    virtual bool IsNetworkConnection() const { return true; }

    virtual PString GetPrefixName() const;

    virtual PBoolean SetUpConnection();

    virtual PBoolean SetAlerting(
      const PString & calleeName,   
      PBoolean withMedia                
    );

    virtual PBoolean SetConnected();

    virtual PBoolean SetProgressed();
    
    virtual void OnEstablished();

    virtual void OnReleased();

    virtual PString GetDestinationAddress();

    virtual PString GetAlertingType() const;

    virtual bool SetAlertingType(const PString & info);

    virtual OpalMediaFormatList GetMediaFormats() const;

    virtual OpalMediaStreamPtr OpenMediaStream(
      const OpalMediaFormat & mediaFormat, 
      unsigned sessionID,                  
      bool isSource                        
    );
    
    virtual bool CloseMediaStream(
      OpalMediaStream & stream  
    );

    virtual PBoolean GetMediaInformation(
      unsigned sessionID,     
      MediaInformation & info 
    ) const;

    virtual void OnCleared();

    PBoolean IsEstablished() const { return connectionState == EstablishedConnection; }

    virtual void CleanUpOnCallEnd();

    virtual void ApplyStringOptions(OpalConnection::StringOptions & stringOptions);


    void AttachSignalChannel(
      const PString & token,    
      H323Transport * channel,  
      PBoolean answeringCall        
    );

    PBoolean WriteSignalPDU(
      H323SignalPDU & pdu       
    );

    virtual void HandleSignallingChannel();

    virtual PBoolean HandleSignalPDU(
      H323SignalPDU & pdu       
    );

    virtual void HandleTunnelPDU(
      H323SignalPDU * txPDU       
    );

    virtual PBoolean OnReceivedSignalSetup(
      const H323SignalPDU & pdu   
    );

    virtual PBoolean OnReceivedSignalSetupAck(
      const H323SignalPDU & pdu   
    );

    virtual PBoolean OnReceivedSignalInformation(
      const H323SignalPDU & pdu   
    );

    virtual PBoolean OnReceivedCallProceeding(
      const H323SignalPDU & pdu   
    );

    virtual PBoolean OnReceivedProgress(
      const H323SignalPDU & pdu   
    );

    virtual PBoolean OnReceivedAlerting(
      const H323SignalPDU & pdu   
    );

    virtual PBoolean OnReceivedSignalConnect(
      const H323SignalPDU & pdu   
    );

    virtual PBoolean OnReceivedFacility(
      const H323SignalPDU & pdu   
    );

    virtual PBoolean OnReceivedSignalNotify(
      const H323SignalPDU & pdu   
    );

    virtual PBoolean OnReceivedSignalStatus(
      const H323SignalPDU & pdu   
    );

    virtual PBoolean OnReceivedStatusEnquiry(
      const H323SignalPDU & pdu   
    );

    virtual void OnReceivedReleaseComplete(
      const H323SignalPDU & pdu   
    );

    virtual PBoolean OnUnknownSignalPDU(
      const H323SignalPDU & pdu  
    );

    virtual void OnSendARQ(
      H225_AdmissionRequest & arq
    );

    virtual void OnReceivedACF(
      const H225_AdmissionConfirm & acf
    );

    virtual void OnReceivedARJ(
      const H225_AdmissionReject & arj
    );

    virtual void OnSendIRR(
      H225_InfoRequestResponse & irr
    ) const;

    virtual void OnSendDRQ(
      H225_DisengageRequest & drq
    ) const;

    virtual PBoolean OnIncomingCall(
      const H323SignalPDU & setupPDU,   
      H323SignalPDU & alertingPDU       
    );

    virtual PBoolean ForwardCall(
      const PString & forwardParty   
    );

    virtual bool TransferConnection(
      const PString & remoteParty   
    );

    virtual bool HoldConnection();

    virtual bool RetrieveConnection();

    virtual PBoolean IsConnectionOnHold();

#if OPAL_H450

    bool TransferCall(
      const PString & remoteParty,   
      const PString & callIdentity = PString::Empty()
    );

    void ConsultationTransfer(
      const PString & primaryCallToken  
    );

    virtual void HandleConsultationTransfer(
      const PString & callIdentity, 
      H323Connection & incoming     
    );

    PBoolean IsTransferringCall() const;

    PBoolean IsTransferredCall() const;

    virtual void HandleTransferCall(
      const PString & token,
      const PString & identity
    );

    int GetCallTransferInvokeId();

    virtual void HandleCallTransferFailure(
      const int returnError    
    );

    void SetAssociatedCallToken(
      const PString & token  
    );

    virtual void OnConsultationTransferSuccess(
      H323Connection & secondaryCall  
    );

    bool HoldCall(
      PBoolean localHold   
    );

    bool RetrieveCall();

    void SetHoldMedia(
      PChannel * audioChannel
    );

    PBoolean IsMediaOnHold() const;

    PBoolean IsLocalHold() const;

    PBoolean IsRemoteHold() const;

    PBoolean IsCallOnHold() const;

    virtual void IntrudeCall(
      unsigned capabilityLevel
    );

    virtual void HandleIntrudeCall(
      const PString & token,
      const PString & identity
    );

    void SetCallIntrusion() { isCallIntrusion = PTrue; }

    PBoolean IsCallIntrusion() { return isCallIntrusion; }

    unsigned GetLocalCallIntrusionProtectionLevel() { return callIntrusionProtectionLevel; }

    virtual PBoolean GetRemoteCallIntrusionProtectionLevel(
      const PString & callToken,
      unsigned callIntrusionProtectionLevel
    );

    virtual void SetIntrusionImpending();

    virtual void SetForcedReleaseAccepted();

    virtual void SetIntrusionNotAuthorized();

    void SendCallWaitingIndication(
      const unsigned nbOfAddWaitingCalls = 0   
    );

#endif

    virtual AnswerCallResponse OnAnswerCall(
      const PString & callerName,       
      const H323SignalPDU & setupPDU,   
      H323SignalPDU & connectPDU,       
      H323SignalPDU & progressPDU       
    );
    
    virtual AnswerCallResponse OnAnswerCall(
      const PString & callerName        
    );

    void AnsweringCall(
      AnswerCallResponse response 
    );

    virtual CallEndReason SendSignalSetup(
      const PString & alias,                
      const H323TransportAddress & address  
    );

    virtual PBoolean OnSendSignalSetup(
      H323SignalPDU & setupPDU   
    );

    virtual PBoolean OnSendCallProceeding(
      H323SignalPDU & callProceedingPDU   
    );

    virtual PBoolean OnSendReleaseComplete(
      H323SignalPDU & releaseCompletePDU 
    );

    virtual PBoolean OnAlerting(
      const H323SignalPDU & alertingPDU,  
      const PString & user                
    );

    virtual PBoolean OnInsufficientDigits();

    virtual void SendMoreDigits(
      const PString & digits    
    );

    virtual PBoolean OnOutgoingCall(
      const H323SignalPDU & connectPDU   
    );

    virtual PBoolean SendFastStartAcknowledge(
      H225_ArrayOf_PASN_OctetString & array   
    );

    virtual PBoolean HandleFastStartAcknowledge(
      const H225_ArrayOf_PASN_OctetString & array   
    );

    virtual PBoolean CreateOutgoingControlChannel(
      const H225_TransportAddress & h245Address   
    );

    virtual PBoolean CreateIncomingControlChannel(
      H225_TransportAddress & h245Address  
    );

    virtual PBoolean WriteControlPDU(
      const H323ControlPDU & pdu
    );

    virtual PBoolean StartControlNegotiations();

    virtual void HandleControlChannel();

    virtual PBoolean HandleControlData(
      PPER_Stream & strm
    );

    virtual PBoolean HandleControlPDU(
      const H323ControlPDU & pdu
    );

    virtual PBoolean OnUnknownControlPDU(
      const H323ControlPDU & pdu  
    );

    virtual PBoolean OnH245Request(
      const H323ControlPDU & pdu  
    );

    virtual PBoolean OnH245Response(
      const H323ControlPDU & pdu  
    );

    virtual PBoolean OnH245Command(
      const H323ControlPDU & pdu  
    );

    virtual PBoolean OnH245Indication(
      const H323ControlPDU & pdu  
    );

    virtual PBoolean OnH245_SendTerminalCapabilitySet(
      const H245_SendTerminalCapabilitySet & pdu  
    );

    virtual PBoolean OnH245_FlowControlCommand(
      const H245_FlowControlCommand & pdu  
    );

    virtual PBoolean OnH245_MiscellaneousCommand(
      const H245_MiscellaneousCommand & pdu  
    );

    virtual PBoolean OnH245_MiscellaneousIndication(
      const H245_MiscellaneousIndication & pdu  
    );

    virtual PBoolean OnH245_JitterIndication(
      const H245_JitterIndication & pdu  
    );

    enum ControlProtocolErrors {
      e_MasterSlaveDetermination,
      e_CapabilityExchange,
      e_LogicalChannel,
      e_ModeRequest,
      e_RoundTripDelay
    };

    virtual PBoolean OnControlProtocolError(
      ControlProtocolErrors errorSource,  
      const void * errorData = NULL       
    );

    virtual void OnSendCapabilitySet(
      H245_TerminalCapabilitySet & pdu  
    );

    virtual PBoolean OnReceivedCapabilitySet(
      const H323Capabilities & remoteCaps,      
      const H245_MultiplexCapability * muxCap,  
      H245_TerminalCapabilitySetReject & reject 
    );

    virtual bool SendCapabilitySet(
      PBoolean empty  
    );

    virtual bool IsSendingCapabilitySet();

    virtual void OnSetLocalCapabilities();

    PBoolean IsH245Master() const;

    void StartRoundTripDelay();

    PTimeInterval GetRoundTripDelay() const;

    virtual void OnSelectLogicalChannels();

    virtual void SelectDefaultLogicalChannel(
      const OpalMediaType & mediaType,  
      unsigned sessionID                
    );

    virtual void SelectFastStartChannels(
      unsigned sessionID,   
      PBoolean transmitter,     
      PBoolean receiver         
    );

    virtual void StartFastStartChannel(
      unsigned sessionID,               
      H323Channel::Directions direction 
    );

    virtual PBoolean OpenLogicalChannel(
      const H323Capability & capability,  
      unsigned sessionID,                 
      H323Channel::Directions dir         
    );
    
    virtual void SendFlowControlCommand(
      unsigned channelNumber,
      unsigned newBitRate
    );
    
    virtual PBoolean OnOpenLogicalChannel(
      const H245_OpenLogicalChannel & openPDU,  
      H245_OpenLogicalChannelAck & ackPDU,      
      unsigned & errorCode                      
    );

    virtual PBoolean OnConflictingLogicalChannel(
      H323Channel & channel    
    );

    virtual H323Channel * CreateLogicalChannel(
      const H245_OpenLogicalChannel & open, 
      PBoolean startingFast,                    
      unsigned & errorCode                  
    );

    virtual H323Channel * CreateRealTimeLogicalChannel(
      const H323Capability & capability, 
      H323Channel::Directions dir,       
      unsigned sessionID,                
      const H245_H2250LogicalChannelParameters * param,
      RTP_QOS * rtpqos = NULL            
    );
    
    virtual H323_RTPChannel * CreateRTPChannel(
      const H323Capability & capability,
      H323Channel::Directions direction,
      RTP_Session & rtp
    );

    virtual PBoolean OnCreateLogicalChannel(
      const H323Capability & capability,  
      H323Channel::Directions dir,        
      unsigned & errorCode                
    );

    virtual PBoolean OnStartLogicalChannel(
      H323Channel & channel    
    );

    virtual void CloseLogicalChannel(
      unsigned number,    
      PBoolean fromRemote     
    );

    virtual void CloseLogicalChannelNumber(
      const H323ChannelNumber & number    
    );

    virtual void CloseAllLogicalChannels(
      PBoolean fromRemote     
    );

    virtual void OnClosedLogicalChannel(
      const H323Channel & channel   
    );

    virtual PBoolean OnClosingLogicalChannel(
      H323Channel & channel   
    );

    virtual void OnLogicalChannelFlowControl(
      H323Channel * channel,   
      long bitRateRestriction  
    );

    virtual void OnLogicalChannelJitter(
      H323Channel * channel,   
      DWORD jitter,            
      int skippedFrameCount,   
      int additionalBuffer     
    );

    H323Channel * GetLogicalChannel(
      unsigned number,    
      PBoolean fromRemote     
    ) const;

    H323Channel * FindChannel(
      unsigned sessionId,   
      PBoolean fromRemote       
    ) const;

    virtual PBoolean SetBandwidthAvailable(
      unsigned newBandwidth,    
      PBoolean force = PFalse        
    );

    virtual unsigned GetBandwidthUsed() const;

    virtual SendUserInputModes GetRealSendUserInputMode() const;

    virtual PBoolean SendUserInputString(
      const PString & value                   
    );

    virtual PBoolean SendUserInputTone(
      char tone,             
      unsigned duration = 0  
    );

    virtual PBoolean SendUserInputIndicationQ931(
      const PString & value                   
    );

    virtual PBoolean SendUserInputIndicationString(
      const PString & value                   
    );

    virtual PBoolean SendUserInputIndicationTone(
      char tone,                   
      unsigned duration = 0,       
      unsigned logicalChannel = 0, 
      unsigned rtpTimestamp = 0    
    );

    virtual PBoolean SendUserInputIndication(
      const H245_UserInputIndication & pdu    
    );

    virtual void OnUserInputIndication(
      const H245_UserInputIndication & pdu  
    );

    virtual H323_RTP_Session * GetSessionCallbacks(
      unsigned sessionID
    ) const;

    virtual RTP_Session * UseSession(
      const OpalTransport & transport,
                   unsigned sessionID,
      const OpalMediaType & mediatype,  
                  RTP_QOS * rtpqos = NULL
    );

    virtual void ReleaseSession(
      unsigned sessionID
    );

    virtual void OnRTPStatistics(
      const RTP_Session & session   
    ) const;

    virtual PString GetSessionCodecNames(
      unsigned sessionID
    ) const;


    virtual PBoolean RequestModeChange(
      const PString & newModes  
    );

    virtual PBoolean RequestModeChange(
      const H245_ArrayOf_ModeDescription & newModes  
    );

    virtual PBoolean OnRequestModeChange(
      const H245_RequestMode & pdu,     
      H245_RequestModeAck & ack,        
      H245_RequestModeReject & reject,  
      PINDEX & selectedMode           
    );

    virtual void OnModeChanged(
      const H245_ModeDescription & newMode
    );

    virtual void OnAcceptModeChange(
      const H245_RequestModeAck & pdu  
    );

    virtual void OnRefusedModeChange(
      const H245_RequestModeReject * pdu  
    );

    virtual PBoolean P_DEPRECATED RequestModeChangeT38(
      const char * capabilityNames = "T.38\nT38FaxUDP"
    );

    virtual PBoolean GetAdmissionRequestAuthentication(
      const H225_AdmissionRequest & arq,  
      H235Authenticators & authenticators 
    );

    H323EndPoint & GetEndPoint() const { return endpoint; }

    PBoolean HadAnsweredCall() const { return !originating; }

    PBoolean IsGatekeeperRouted() const { return gatekeeperRouted; }

    unsigned GetDistinctiveRing() const { return distinctiveRing; }

    void SetDistinctiveRing(unsigned pattern) { distinctiveRing = pattern&7; }

    const PString & GetCallToken() const { return GetToken(); }

    unsigned GetCallReference() const { return callReference; }

    inline const OpalGloballyUniqueID & GetCallIdentifier() const 
    { return callIdentifier; }

    virtual PString GetIdentifier() const;

    const OpalGloballyUniqueID & GetConferenceIdentifier() const { return conferenceIdentifier; }

    void SetLocalPartyName(const PString & name);

    const PStringList & GetLocalAliasNames() const { return localAliasNames; }

    virtual void SetRemotePartyInfo(
      const H323SignalPDU & pdu 
    );

    void SetRemoteApplication(
      const H225_EndpointType & pdu 
    );
    
    PString GetRemotePartyURL() const;
    
    const H323Capabilities & GetLocalCapabilities() const { return localCapabilities; }

    const H323Capabilities & GetRemoteCapabilities() const { return remoteCapabilities; }

    unsigned GetRemoteMaxAudioDelayJitter() const { return remoteMaxAudioDelayJitter; }

    const H323Transport * GetSignallingChannel() const { return signallingChannel; }

    unsigned GetSignallingVersion() const { return h225version; }

    const H323Transport & GetControlChannel() const;

    OpalTransport & GetTransport() const;

    unsigned GetControlVersion() const { return h245version; }

    unsigned GetUUIEsRequested() const { return uuiesRequested; }

    void SetUUIEsRequested(unsigned mask) { uuiesRequested = mask; }

    const PString GetGkAccessTokenOID() const { return gkAccessTokenOID; }

    void SetGkAccessTokenOID(const PString & oid) { gkAccessTokenOID = oid; }

    const PBYTEArray & GetGkAccessTokenData() const { return gkAccessTokenData; }

    void SetDestExtraCallInfo(
      const PString & info
    ) { destExtraCallInfo = info; }

    void SetRemotCallWaiting(const unsigned value) { remoteCallWaiting = value; }

    int GetRemoteCallWaiting() const { return remoteCallWaiting; }

    void SetEnforcedDurationLimit(
      unsigned seconds  
    );
        
    virtual PBoolean OnSendFeatureSet(unsigned, H225_FeatureSet &) const;
        
        virtual void OnReceiveFeatureSet(unsigned, const H225_FeatureSet &) const;

#if OPAL_H460

    virtual H460_FeatureSet * GetFeatureSet();
#endif

    
#if OPAL_H450

    H4507Handler&  getH4507handler(){return *h4507handler;}
#endif

    virtual void OnMediaCommand(OpalMediaCommand & note, INT extra);
    
    // H.245 - compliant handling of session IDs
    // if no internal session ID is found, zero is returned
    unsigned GetExternalSessionID(unsigned internalSessionID) const;
    unsigned GetExternalSessionID(unsigned internalSessionID, const OpalMediaType & mediaType);
    unsigned GetInternalSessionID(unsigned externalSessionID, const OpalMediaType & mediaType);

  protected:
    virtual void InternalEstablishedConnectionCheck();
    PBoolean InternalEndSessionCheck(PPER_Stream & strm);
    void SetRemoteVersions(const H225_ProtocolIdentifier & id);
    void MonitorCallStatus();
    PDECLARE_NOTIFIER(PThread, H323Connection, StartOutgoing);
    PDECLARE_NOTIFIER(PThread, H323Connection, NewOutgoingControlChannel);
    PDECLARE_NOTIFIER(PThread, H323Connection, NewIncomingControlChannel);

    H323EndPoint & endpoint;

    int                  remoteCallWaiting; // Number of call's waiting at the remote endpoint
    PBoolean                 gatekeeperRouted;
    unsigned             distinctiveRing;
    unsigned             callReference;
    OpalGloballyUniqueID callIdentifier;
    OpalGloballyUniqueID conferenceIdentifier;

    PString            localDestinationAddress;
    PStringList        localAliasNames;
    H323Capabilities   localCapabilities; // Capabilities local system supports
    PString            destExtraCallInfo;
    H323Capabilities   remoteCapabilities; // Capabilities remote system supports
    unsigned           remoteMaxAudioDelayJitter;
    PTimer             roundTripDelayTimer;
    WORD               maxAudioDelayJitter;
    unsigned           uuiesRequested;
    PString            gkAccessTokenOID;
    PBYTEArray         gkAccessTokenData;
    PBoolean               addAccessTokenToSetup;

    H323Transport * signallingChannel;
    H323Transport * controlChannel;
    OpalListener  * controlListener;
    PBoolean            h245Tunneling;
    H323SignalPDU * h245TunnelRxPDU;
    H323SignalPDU * h245TunnelTxPDU;
    H323SignalPDU * setupPDU;
    H323SignalPDU * alertingPDU;
    H323SignalPDU * connectPDU;
    H323SignalPDU * progressPDU;

    enum ConnectionStates {
      NoConnectionActive,
      AwaitingGatekeeperAdmission,
      AwaitingTransportConnect,
      AwaitingSignalConnect,
      AwaitingLocalAnswer,
      HasExecutedSignalConnect,
      EstablishedConnection,
      ShuttingDownConnection,
      NumConnectionStates
    } connectionState;

    unsigned   h225version;
    unsigned   h245version;
    PBoolean       h245versionSet;
    PBoolean doH245inSETUP;
    PBoolean lastPDUWasH245inSETUP;

    PBoolean mustSendDRQ;
    PBoolean mediaWaitForConnect;
    PBoolean transmitterSidePaused;
    bool     remoteTransmitPaused;
    PBoolean earlyStart;
    PString    t38ModeChangeCapabilities;
    PSyncPoint digitsWaitFlag;
    PBoolean       endSessionNeeded;
    PSyncPoint endSessionReceived;
    PTimer     enforcedDurationLimit;

    // Used as part of a local call hold operation involving MOH
    PChannel * holdMediaChannel;
    PBoolean       isConsultationTransfer;

    PBoolean     isCallIntrusion;
    unsigned callIntrusionProtectionLevel;

    enum FastStartStates {
      FastStartDisabled,
      FastStartInitiate,
      FastStartResponse,
      FastStartAcknowledged,
      NumFastStartStates
    };
    FastStartStates        fastStartState;
    H323LogicalChannelList fastStartChannels;
    OpalMediaStreamPtr     fastStartMediaStream;
    
    // H.245 - compliant handling of session IDs
    unsigned nextSessionID;
    typedef std::map<unsigned, unsigned> InternalToExternalSessionIDMap;
    typedef std::map<OpalMediaType, unsigned> MediaTypeToInternalSessionIDMap;
    InternalToExternalSessionIDMap internalToExternalSessionIDMap;
    MediaTypeToInternalSessionIDMap mediaTypeToInternalSessionIDMap;
    PMutex sessionIDHandlingMutex;

#if PTRACING
    static const char * GetConnectionStatesName(ConnectionStates s);
    friend ostream & operator<<(ostream & o, ConnectionStates s) { return o << GetConnectionStatesName(s); }
    static const char * GetFastStartStateName(FastStartStates s);
    friend ostream & operator<<(ostream & o, FastStartStates s) { return o << GetFastStartStateName(s); }
#endif


    // The following pointers are to protocol procedures, they are pointers to
    // hide their complexity from the H323Connection classes users.
    H245NegMasterSlaveDetermination  * masterSlaveDeterminationProcedure;
    H245NegTerminalCapabilitySet     * capabilityExchangeProcedure;
    H245NegLogicalChannels           * logicalChannels;
    H245NegRequestMode               * requestModeProcedure;
    H245NegRoundTripDelay            * roundTripDelayProcedure;

#if OPAL_H450
    H450xDispatcher                  * h450dispatcher;
    H4502Handler                     * h4502handler;
    H4504Handler                     * h4504handler;
    H4506Handler                     * h4506handler;
    H4507Handler                     * h4507handler;
    H45011Handler                    * h45011handler;
#endif

#if OPAL_H460
    H460_FeatureSet * features;
#endif

  private:
    PChannel * SwapHoldMediaChannels(PChannel * newChannel);
};


PDICTIONARY(H323CallIdentityDict, PString, H323Connection);


#endif // OPAL_H323

#endif // OPAL_H323_H323CON_H

---