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Receiving unknown RDP surface command when TS_NEG_MULTISCRBLT_INDEX is disabled RRS feed

  • Question

  • Hi

    (Axel manufacture "O.S. less" thin clients with an home made RDP client)

    We experienced a strange issue with server 2012(R2) when opening an RDP session in 32bpp.

    If the TS_NEG_MULTISCRBLT_INDEX is disabled (RDPBCGR.pdf, Chapter 2.2.7.1.3), the thin client will received an unknown surface command (0x80). This unknown command is correctly surrounded by a FRAMEMARKER BEGIN and an FRAMERMARKER END surface commands.

    IMPORTANT: This unknown surface command is only received when:
      - the color depth is 32bbp AND
      - the RDP server is Win2012 AND
      - the TS_NEG_MULTISCRBLT_INDEX is disabled

    Could you check this issue and let me know if this unknown surface command (0x80) is actually an undocumented command or if it's an unexpected server behavior.

    If needed, I can send you a decrypted 'Network Monitor' trace (the incorrect surface command is displayed as "ParserError: Unknown Cmd type").

    Best regards

    Vincent

    Wednesday, December 11, 2013 11:05 AM

Answers

  • Hi Vincent:

    I'll help you with this issue.

    Please send a decrypted trace with info as to which frame(s) contains the unknown surface command to my attention to dochelp at Microsoft dot com.


    Regards, Obaid Farooqi

    Wednesday, December 11, 2013 5:21 PM
    Owner
  • Hi Ethois:

    This issue is resolved. In a future release of MS-RDPBCGR, following WBN's (Windows Behavior Notes) will be added in section 6:

    <WBN> Section 2.2.7.1.3: Clients that support Surface Commands (section 2.2.9.2) and advertise support for TS_NEG_SCRBLT_INDEX (0x02) MUST also advertise support for TS_NEG_MEMBLT_INDEX (0x03) when connecting to RDP 8.0 and 8.1 servers.

    <WBN> Section 2.2.7.1.3: Clients that support Surface Commands (section 2.2.9.2) and advertise support for TS_NEG_MEMBLT_INDEX (0x03) MUST also advertise support for TS_NEG_SCRBLT_INDEX (0x02) when connecting to RDP 8.0 and 8.1 servers.


    Regards, Obaid Farooqi

    Friday, February 14, 2014 10:24 PM
    Owner

All replies

  • Hi Vincent,
    Thank you for this inquiry. One of our team members will follow-up soon and work with you on this.

    Regards,
    Edgar

    Wednesday, December 11, 2013 4:10 PM
    Moderator
  • Hi Vincent:

    I'll help you with this issue.

    Please send a decrypted trace with info as to which frame(s) contains the unknown surface command to my attention to dochelp at Microsoft dot com.


    Regards, Obaid Farooqi

    Wednesday, December 11, 2013 5:21 PM
    Owner
  • What was the outcome of this?
    Friday, February 14, 2014 8:27 PM
  • Hi Ethois:

    This issue is resolved. In a future release of MS-RDPBCGR, following WBN's (Windows Behavior Notes) will be added in section 6:

    <WBN> Section 2.2.7.1.3: Clients that support Surface Commands (section 2.2.9.2) and advertise support for TS_NEG_SCRBLT_INDEX (0x02) MUST also advertise support for TS_NEG_MEMBLT_INDEX (0x03) when connecting to RDP 8.0 and 8.1 servers.

    <WBN> Section 2.2.7.1.3: Clients that support Surface Commands (section 2.2.9.2) and advertise support for TS_NEG_MEMBLT_INDEX (0x03) MUST also advertise support for TS_NEG_SCRBLT_INDEX (0x02) when connecting to RDP 8.0 and 8.1 servers.


    Regards, Obaid Farooqi

    Friday, February 14, 2014 10:24 PM
    Owner