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Voice & video calls between R1/Win 2000 MOC and R2/XPSP2 MOC fail with "Incompatible Security" error RRS feed

  • Question


  • Hi All,

    I have a problem I'd like to get the community's feedback on.

    I've deployed OCS2007R2 EE, and have some Windows2000 clients and some WinXPSP2 client machines. Because the R2MOC does not work on Windows 2000, I've had to deploy the R1 MOC to those machines. According to the OCS R2 Supportability Guide, this is a supported configuration, and it doesn't say anything about security incompatibility. I'm having trouble when a Win2000 user and XP user call each other.

    Client A is running Windows 2000, SP4, with MOC 2007 (R1) with the July 2009 update pack
    Client B is running XP SP2, MOC 2007 R2 with the June 2009 update pack

    The OCS Front End is EE,2007 R2

    The two can IM and get presence, but calls fail with an "Incompatible Security" error.

    Can someone tell me if this is a security mismatch between the R1 and R2 MOCs or is it a security mismatch in the Win2000 and XP OS's?

    I know I can turn media security off with the PC2PCAVEncryption reg key, but I'd rather not. If there's a patch that I'm missing, I'd much rather go that route.

    Thanks in advance for all the advice!
    Sunday, October 25, 2009 9:11 PM

Answers

  • Nobody seems to know the answer to this, probably because nobody uses Windows 2000 any more.
    Here's the cause - the R1&R2 MOCs use SRTP for all A/V streams. There is no support for SRTP in Windows 2000.
    There are also no KB's that describe this as an issue, despite the R1 MOC being supported on Windows 2000. I presume that's because Windows 2000 is EOL?
    So, what I've gathered is that you cannot have voice or video with OCS R1 or R2 and Windows 2000 clients. IM & Presence are the only OCS functions available to any users on Windows 2000.
    • Marked as answer by bradpr Tuesday, October 27, 2009 6:08 PM
    Tuesday, October 27, 2009 6:07 PM

All replies

  • I'm now offsite, so I don't have a Windows 2000 system to test with (surprising that MSFT doesn't make Win2K available to technet subscribers any more. I can download 3.11, but not NT4 or Win2K - go figure).


    So, I built a lab with XP clients running against an OCS R2 EE infrastructure. I tested an unpatched R1 client on XPSP3 calling an unpatched R2 client on XPSP3 and conducted a voice call with no issue. This makes me think that the issue is between XP and Win2K crypto.

    I have this thread, plus a thread in the OCS setup forum, plus an email to Rui Silva, and NOBODY has given me the smallest suggestion of what could be the root cause. So, I'm offering untold riches in reward to anyone who even acknowledges that they've read any of my posts. Furthermore, you'll receive a greater reward if you actually know what I'm talking about.

    Thanks again in advance & your soul will be blessed.
    Monday, October 26, 2009 6:19 PM
  • Nobody seems to know the answer to this, probably because nobody uses Windows 2000 any more.
    Here's the cause - the R1&R2 MOCs use SRTP for all A/V streams. There is no support for SRTP in Windows 2000.
    There are also no KB's that describe this as an issue, despite the R1 MOC being supported on Windows 2000. I presume that's because Windows 2000 is EOL?
    So, what I've gathered is that you cannot have voice or video with OCS R1 or R2 and Windows 2000 clients. IM & Presence are the only OCS functions available to any users on Windows 2000.
    • Marked as answer by bradpr Tuesday, October 27, 2009 6:08 PM
    Tuesday, October 27, 2009 6:07 PM