Call-Transfer-Operations {itu-t recommendation h 450 2 version1(0)
  call-transfer-operations(0)} DEFINITIONS AUTOMATIC TAGS ::=
BEGIN

IMPORTS
  OPERATION, ERROR
    FROM Remote-Operations-Information-Objects {joint-iso-itu-t
      remote-operations(4) informationObjects(5) version1(0)}
  EXTENSION, Extension{}
    FROM Manufacturer-specific-service-extension-definition {itu-t
      recommendation h 450 1 version1(0) msi-definition(18)}
  notAvailable, supplementaryServiceInteractionNotAllowed, invalidCallState
    FROM H4501-General-Error-List {itu-t recommendation h 450 1 version1(0)
      general-error-list(1)}
  EndpointAddress, PartySubaddress
    FROM Addressing-Data-Elements {itu-t recommendation h 450 1 version1(0)
      addressing-data-elements(9)}
  NonStandardParameter
    FROM H323-MESSAGES -- see H.225.0
      
  H225InformationElement
    FROM H225-generic-parameters-definition {itu-t recommendation h 450 
      1 version1(0) h225-generic-parameters(6)};

H323CallTransferOperations OPERATION ::=
  {callTransferIdentify | callTransferAbandon | callTransferInitiate |
   callTransferSetup | callTransferUpdate | subaddressTransfer |
   callTransferComplete | callTransferActive}

callTransferIdentify OPERATION ::= {
  -- sent from transferring endpoint to transferred-to endpoint
  ARGUMENT  DummyArg
  OPTIONAL  TRUE
  RESULT    CTIdentifyRes
  ERRORS
    {notAvailable | invalidCallState |
      supplementaryServiceInteractionNotAllowed | unspecified}
  CODE      local:7
}

callTransferAbandon OPERATION ::= {
  -- sent from transferring to transferred-to endpoint
  ARGUMENT         DummyArg
  OPTIONAL         TRUE
  RETURN RESULT    FALSE
  ALWAYS RESPONDS  FALSE
  CODE             local:8
}

callTransferInitiate OPERATION ::= {
  -- sent from transfering to transferred endpoint
  ARGUMENT  CTInitiateArg
  RESULT    DummyRes
  OPTIONAL  TRUE
  ERRORS
    {notAvailable | invalidCallState | invalidReroutingNumber |
      unrecognizedCallIdentity | establishmentFailure |
      supplementaryServiceInteractionNotAllowed | unspecified}
  CODE      local:9
}

callTransferSetup OPERATION ::= {
  -- sent from transferred to transferred-to endpoint
  ARGUMENT  CTSetupArg
  RESULT    DummyRes
  OPTIONAL  TRUE
  ERRORS
    {notAvailable | invalidCallState | invalidReroutingNumber |
      unrecognizedCallIdentity | unspecified |
      supplementaryServiceInteractionNotAllowed}
  CODE      local:10
}

callTransferUpdate OPERATION ::= {
  -- may be sent from transferred to transferred-to endpoint (in SETUP) and
  -- vice versa (in CONNECT)
  ARGUMENT         CTUpdateArg
  RETURN RESULT    FALSE
  ALWAYS RESPONDS  FALSE
  CODE             local:13
}

subaddressTransfer OPERATION ::= {
  -- may be sent from transferred to the transferred-to endpoint and vice versa
  ARGUMENT         SubaddressTransferArg
  RETURN RESULT    FALSE
  ALWAYS RESPONDS  FALSE
  CODE             local:14
}

callTransferComplete OPERATION ::= {
  -- sent from GK to the transferred endpoint, if GK performs call transfer 
  -- (see 10.6.1).
  ARGUMENT         CTCompleteArg
  RETURN RESULT    FALSE
  ALWAYS RESPONDS  FALSE
  CODE             local:12
}

callTransferActive OPERATION ::= {
  -- sent from gatekeeper to the transferred endpoint, in case of transfer ringing
  -- after transferred-to endpoint has answered the call (only in case of
  -- transfer performed by gatekeeper)
  ARGUMENT         CTActiveArg
  RETURN RESULT    FALSE
  ALWAYS RESPONDS  FALSE
  CODE             local:11
}

DummyArg ::= CHOICE {
  extensionSeq     ExtensionSeq,
  nonStandardData  NonStandardParameter
}

DummyRes ::= CHOICE {
  extensionSeq     ExtensionSeq,
  nonStandardData  NonStandardParameter
}

CTInitiateArg ::= SEQUENCE {
  callIdentity       CallIdentity,
  reroutingNumber    EndpointAddress,
  argumentExtension
    CHOICE {extensionSeq     ExtensionSeq,
            nonStandardData  NonStandardParameter} OPTIONAL,
  ...
}

CTSetupArg ::= SEQUENCE {
  callIdentity        CallIdentity,
  transferringNumber  EndpointAddress OPTIONAL,
  argumentExtension
    CHOICE {extensionSeq     ExtensionSeq,
            nonStandardData  NonStandardParameter} OPTIONAL,
  ...
}

CTIdentifyRes ::= SEQUENCE {
  callIdentity     CallIdentity,
  reroutingNumber  EndpointAddress,
  resultExtension
    CHOICE {extensionSeq     ExtensionSeq,
            nonStandardData  NonStandardParameter} OPTIONAL,
  ...
}

CTUpdateArg ::= SEQUENCE {
  redirectionNumber      EndpointAddress,
  redirectionInfo        BMPString(SIZE (1..128)) OPTIONAL,
  basicCallInfoElements  H225InformationElement OPTIONAL,
  -- Information element 
  -- Progress indicator may be conveyed
  argumentExtension
    CHOICE {extensionSeq     ExtensionSeq,
            nonStandardData  NonStandardParameter} OPTIONAL,
  ...
}

SubaddressTransferArg ::= SEQUENCE {
  redirectionSubaddress  PartySubaddress,
  argumentExtension
    CHOICE {extensionSeq     ExtensionSeq,
            nonStandardData  NonStandardParameter} OPTIONAL,
  ...
}

CTCompleteArg ::= SEQUENCE {
  endDesignation         EndDesignation,
  redirectionNumber      EndpointAddress,
  -- number of new connected user
  basicCallInfoElements  H225InformationElement OPTIONAL,
  -- Information element Progress indicator may be conveyed
  redirectionInfo        BMPString(SIZE (1..128)) OPTIONAL,
  callStatus             CallStatus DEFAULT answered,
  argumentExtension
    CHOICE {extensionSeq     ExtensionSeq,
            nonStandardData  NonStandardParameter} OPTIONAL,
  ...
}

EndDesignation ::= ENUMERATED {primaryEnd(0), secondaryEnd(1), ...
                               }

CallStatus ::= ENUMERATED {answered(0), alerting(1), ...
                           }

CTActiveArg ::= SEQUENCE {
  connectedAddress       EndpointAddress,
  -- number of new connected user
  basicCallInfoElements  H225InformationElement OPTIONAL,
  -- Information element Progress indicator may be conveyed
  connectedInfo          BMPString(SIZE (1..128)) OPTIONAL,
  argumentExtension
    CHOICE {extensionSeq     ExtensionSeq,
            nonStandardData  NonStandardParameter} OPTIONAL,
  ...
}

CallIdentity ::= NumericString(SIZE (0..4))

-- size 0 means 'empty'
ExtensionSeq ::= SEQUENCE OF Extension{{ExtensionSet}}

ExtensionSet EXTENSION ::=
  {...}

-- Actual values defined by individual manufacturers
unspecified ERROR ::= {
  PARAMETER
    CHOICE {extension    Extension{{ExtensionSet}},
            nonStandard  NonStandardParameter}
  CODE       local:1008
}

invalidReroutingNumber ERROR ::= {
  -- used when establishment of the new connection fails
  -- because the reroutingNumber is not a valid alias address
  CODE  local:1004
}

unrecognizedCallIdentity ERROR ::= {
  -- used when establishment of the new connection fails because it
  -- could not be associated with a SS-CT entity at the 
  -- transferred-to endpoint
  CODE  local:1005
}

establishmentFailure ERROR ::= {
  -- used when establishment of the new connection fails and
  -- no other error applies
  CODE  local:1006
}

END -- of Call-Transfer-Operations