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[MSRDP-EMC]Second client receive participant created PDU without IS_PARTICIPANT flag set. RRS feed

  • Question

  • Scene:

    Remote Assistance Novice (Host) x 1

    Remote Assistance Expert (Client) x 2

    Expert #1 client connected to novice, expert #1 received the participant pdu like this:

    participantId: 1, groupId: 0,  flags: 4(IS_PARTICIPANT),  Friendlyname: ....

    everything seems normal.

    When I connect Expert #2 to the host, it's supposed to receive 2 participant pdu, one of them with the IS_PARTICIPANT set to 1. but actually I got 2 PDU like this:

    participantId: 1, groupId: 0,  flags: 0,  Friendlyname: ....

    participantId: 2, groupId: 0,  flags: 0,  Friendlyname: ....

    participantId #2 should be expert #2, but IS_PARTICIPANT was not set.

    Then I disconnected both expert #1 and expert #2,  

    Connect expert #2 again, I got this:

    participantId: 3, groupId: 0,  flags: 4(IS_PARTICIPANT),  Friendlyname: ....

    This was weird.

    Why ONLY the first online expert gets IS_PARTICIPANT flag? 


    Reference: MSRDP-EMC Appendix A

    <16> Section 3.2.5.2.1: When a client is connected and authenticated, the server tries to inform 
    the client which participant in the list corresponds to the client itself. This communication is done by 
    sending a Participant-Created PDU to only that client but with the IS_PARTICIPANT set to 1. The 
    client verifies the presence of the flag and remembers the ParticipantId as corresponding to itself. 


    Friday, March 9, 2012 3:34 AM

Answers

  • Hi UrsaeMinoris

    Can you please drop me a mail at "dochelp (at) microsoft (dot) com" ? I will walk you through the steps to capture and decrypt traffic using Netmon as encrypted traffic will not help us in confirming the behaviour you are observing.

    Thanks


    Tarun Chopra | Escalation Engineer | Open Specifications Support Team

    • Marked as answer by UrsaeMinoris Saturday, March 17, 2012 6:19 PM
    • Unmarked as answer by UrsaeMinoris Saturday, March 17, 2012 6:20 PM
    • Marked as answer by UrsaeMinoris Saturday, March 17, 2012 6:21 PM
    Thursday, March 15, 2012 1:42 PM

All replies

  • Hi UrsaeMinoris:

    I have alerted The Open Specification Team regarding your inquiry. A member of the team will be in touch soon.


    Regards, Obaid Farooqi

    Friday, March 9, 2012 5:56 PM
    Owner
  • Hi UrsaeMinoris:

    I will assist you with this issue. Would appreciate if you can please share the network trace by e-mail to "dochelp (at) microsoft (dot) com".

    Thanks


    Tarun Chopra | Escalation Engineer | Open Specifications Support Team

    Friday, March 9, 2012 6:57 PM
  • Hi UrsaeMinoris:

    Still looking forward to receive trace files from you for further analysis. Please let me know if you are facing any issue in reaching us at above email id.

    Thanks.


    Tarun Chopra | Escalation Engineer | Open Specifications Support Team

    Wednesday, March 14, 2012 1:57 AM
  • Sorry for the late reply.

    I can capture the RDP packets by using wireshark, but the content was encrypted. 

    Could this be useful for you?

    Thursday, March 15, 2012 8:33 AM
  • Hi UrsaeMinoris

    Can you please drop me a mail at "dochelp (at) microsoft (dot) com" ? I will walk you through the steps to capture and decrypt traffic using Netmon as encrypted traffic will not help us in confirming the behaviour you are observing.

    Thanks


    Tarun Chopra | Escalation Engineer | Open Specifications Support Team

    • Marked as answer by UrsaeMinoris Saturday, March 17, 2012 6:19 PM
    • Unmarked as answer by UrsaeMinoris Saturday, March 17, 2012 6:20 PM
    • Marked as answer by UrsaeMinoris Saturday, March 17, 2012 6:21 PM
    Thursday, March 15, 2012 1:42 PM