2.2.2.2.2 UDP: Presence Response

When a device receives a presence request, it responds with a presence response to notify that it’s available.


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MessageType

DiscoveryType

ConnectionMode

DeviceType

DeviceNameLength

DeviceName (variable)

...

...

DeviceIdSalt

DeviceIdHash

MessageType (1 byte): Indicates current message type – in this case, Discovery (1).

DiscoveryType (1 byte): Indicates type of discovery message, in this case, Presence Response (1).

ConnectionMode (2 bytes): Displays types of available connections.

Value

Meaning

0

None

1

Proximal

2

Legacy

DeviceType (2 bytes): SKU of the device

Value

Meaning

1

Xbox One

6

Apple iPhone

7

Apple iPad

8

Android device

9

Windows 10 Desktop

11

Windows 10 Phone

12

Linux device

13

Windows IoT

14

Surface Hub

DeviceNameLength (2 bytes): Length of the machine name of the device.

DeviceName (variable): This is character representation of the name of the device. The size of the list is bounded by the previous message.

DeviceIdSalt (4 bytes): A randomly generated salt.

DeviceIdHash (4 bytes): Salted SHA-256 hash of the internal CDP device ID. This is used to correlate the advertising device to a list of known devices without advertising the full device ID.

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