2.2.11.2 Client Refresh Rect PDU

The Refresh Rect PDU allows the client to request that the server redraw one or more rectangles of the session screen area. The client can use it to repaint sections of the client window that were obscured by local applications.<37> Server support for this PDU is indicated in the General Capability Set (section 2.2.7.1.1).


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tpktHeader

x224Data

mcsSDrq (variable)

...

securityHeader (variable)

...

refreshRectPduData (variable)

...

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.

mcsSDrq (variable): Variable-length PER-encoded MCS Domain PDU (DomainMCSPDU) that encapsulates an MCS Send Data Request structure (SDrq, choice 25 from DomainMCSPDU), as specified in [T125] section 11.32 (the ASN.1 structure definitions are given [T125] in section 7, parts 7 and 10). The userData field of the MCS Send Data Request contains a Security Header and a Refresh Rect PDU Data (section 2.2.11.2.1) structure.

securityHeader (variable): Optional security header. The presence and format of the security header depends on the Encryption Level and Encryption Method selected by the server (sections 5.3.2 and 2.2.1.4.3). If the Encryption Level selected by the server is greater than ENCRYPTION_LEVEL_NONE (0) and the Encryption Method selected by the server is greater than ENCRYPTION_METHOD_NONE (0), then this field MUST contain one of the following headers:

If the Encryption Level selected by the server is ENCRYPTION_LEVEL_NONE (0) and the Encryption Method selected by the server is ENCRYPTION_METHOD_NONE (0), then this header MUST NOT be included in the PDU.

refreshRectPduData (variable): The actual contents of the Refresh Rect PDU, as specified in section 2.2.11.2.1.