2.2.1.4 Server MCS Connect Response PDU with GCC Conference Create Response

The MCS Connect Response PDU is an RDP Connection Sequence PDU sent from server to client during the Basic Settings Exchange phase of the RDP Connection Sequence (see section 1.3.1.1 for an overview of the RDP Connection Sequence phases). It is sent as a response to the MCS Connect Initial PDU (section 2.2.1.3). The MCS Connect Response PDU encapsulates a GCC Conference Create Response, which encapsulates concatenated blocks of settings data. A basic high-level overview of the nested structure for the Server MCS Connect Response PDU is illustrated in section 1.3.1.1, in the figure specifying MCS Connect Response PDU. Note that the order of the settings data blocks is allowed to vary from that shown in the previously mentioned figure and the message syntax layout that follows. This is possible because each data block is identified by a User Data Header structure (section 2.2.1.4.1).


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tpktHeader

x224Data

mcsCrsp (variable)

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gccCCrsp (variable)

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serverCoreData (variable)

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serverNetworkData (variable)

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serverSecurityData (variable)

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serverMessageChannelData (optional)

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serverMultitransportChannelData (optional)

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tpktHeader (4 bytes): A TPKT Header, as specified in [T123] section 8.

x224Data (3 bytes): An X.224 Class 0 Data TPDU, as specified in [X224] section 13.7.

mcsCrsp (variable): Variable-length BER-encoded MCS Connect Response structure (using definite-length encoding) as described in [T125] section 11.2 (the ASN.1 structure definition is detailed in [T125] section 7, part 2). The userData field of the MCS Connect Response encapsulates the GCC Conference Create Response data (contained in the gccCCrsp and subsequent fields).

gccCCrsp (variable): Variable-length PER-encoded GCC Connect Data structure which encapsulates a Connect GCC PDU that contains a GCC Conference Create Response structure as described in [T124] (the ASN.1 structure definitions are specified in [T124] section 8.7) appended as user data to the MCS Connect Response (using the format specified in [T124] sections 9.5 and 9.6). The userData field of the GCC Conference Create Response contains one user data set consisting of concatenated Server Data Blocks.

serverCoreData (variable): Variable-length Server Core Data structure (section 2.2.1.4.2).

serverNetworkData (variable): Variable-length Server Network Data structure (section 2.2.1.4.4).

serverSecurityData (variable): Variable-length Server Security Data structure (section 2.2.1.4.3).

serverMessageChannelData (6 bytes): Optional Server Message Channel Data structure (section 2.2.1.4.5). This field MUST NOT be included if the client did not populate the optional clientMessageChannelData field in the MCS Connect Initial PDU (section 2.2.1.3).

serverMultitransportChannelData (8 bytes): Optional Server Multitransport Channel Data structure (section 2.2.1.4.6). This field MUST NOT be included if the client did not populate the optional clientMultitransportChannelData field in the MCS Connect Initial PDU (section 2.2.1.3).

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