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Miracast - documentation error implemented in capability attribute RRS feed

  • Question

  • Another miracast question.

    In MS-MICE v1.0, MS-MICE v1.1, and MS-MICE v2.0, the capability attribute of the Vendor Extension is documented as having two possible values: b'00001000' (0x08) or b'10001000' (0x88).

    The Vendor Extension Example in section 4.1 of MS-MICE v1.0, shows that capability attribute as:

        ...

        2001   // Capability Attribute

        0001   // Size: 1 Byte

        05      // Capability

        ...

    MS-MICE v1.1 and v2.0 correct the capability byte example to be 0x88. When I do a packet capture on a surface hub, I am seeing that the surface hub is advertising its capability as 0x05.

    Packet Capture Highlighting Vendor Extension

    My question, is which one is correct? Should Miracast sources just always check for mDNS broadcasts regardless of the capability attribute? Is that what Windows Miracast sources do?

    Friday, July 6, 2018 9:29 PM

Answers

  • Vincent,

    What you are observing in the packet capture is correct. Capability 0x5 is the default.

    Bit A - MiracastOverInfrastructureSupport: 1 = supported.

    Bit C – Version: 1

    The 88 Capability Info in the example in Section 4.1 is a document issue that we will address in a future release of the document.

    Thanks,

    Edgar

    Thursday, July 19, 2018 3:55 AM
    Moderator

All replies

  • Hi Vincent,

    Thank you for posting your question regarding the Miracast family of protocols. A support case has been created for your posting, and a member of the Open Specifications Support team will be posting here in regards to your question.

    Will Gregg | open specifications

    Friday, July 6, 2018 11:58 PM
    Moderator
  • Hello Vincent,

    We are reviewing this and will follow-up.

    Thank you,

    Edgar

    Monday, July 9, 2018 4:08 PM
    Moderator
  • Any progress?
    Friday, July 13, 2018 7:58 PM
  • Vincent,

    What you are observing in the packet capture is correct. Capability 0x5 is the default.

    Bit A - MiracastOverInfrastructureSupport: 1 = supported.

    Bit C – Version: 1

    The 88 Capability Info in the example in Section 4.1 is a document issue that we will address in a future release of the document.

    Thanks,

    Edgar

    Thursday, July 19, 2018 3:55 AM
    Moderator
  • Ahh, I see now. Thanks for the clarification!

    Thursday, July 19, 2018 5:32 PM