2.2.2 Tethering Identifier IE

The Tethering Identifier information element (IE) SHOULD<3> be used to differentiate tethering (device-based) networks from stand-alone APs. The structure of the Tethering Identifier IE is shown in the following packet.


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Attribute_ID

Length

OUI

...

OUI_Type

Type

Length

MAC_Address

...

Attribute_ID (1 byte): Contains the ID of the element as specified [IEEE802.11-2007] section 7.3.2. It MUST contain a value of 221 (0xDD), identifying a vendor-specific element (as specified in [IEEE802.11-2007] table 26) in which the vendor is identified by an IEEE-issued OUI.

Length (1 byte): The length of the subsequent fields. This value MUST be 14 (0x0E).

OUI (3 bytes): The IEEE-assigned organizationally unique identifier (OUI) for Microsoft. The OUI field MUST contain a value of (00:50:F2) as specified in [IEEE-OUI].

OUI_Type (1 byte): A packet subtype within the universe specific to a specific OUI value. For the Tethering Identifier IE, the OUI Type MUST contain a value of 18 (0x12).

Type (2 bytes): Used to specify that the network is broadcasted as tethered. The Type field MUST contain a value of 43 (0x2B).

Length (2 bytes): Contains the length of the MAC_Address field in octets. This value MUST be 6 (0x06).

MAC_Address (6 bytes): Contains the Medium Access Control (MAC) address of the AP.