Re: Proposed update to DLT_BLUETOOTH_LE_LL_WITH_PHDR

[Sultan Khan via tcpdump-workers <tcpdump-workers () lists tcpdump org>]

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> From: Sultan Khan <sultanqasim () gmail com>
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> Date: Fri, 10 Jul 2020 19:04:44 -0400
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> The reason the extra auxiliary PDU type field is needed is that the
> four-bit auxiliary PDU type is ambiguous and context-dependent for
> auxiliary PDUs. See Volume 6, Part B, Section 2.3, Table 2.3. The four
> least significant bits of the advertising PDU header will be 0b0111 for
> AUX_ADV_IND, AUX_CHAIN_IND, AUX_SYNC_IND, and AUX_SCAN_RSP, so you need
> extra information to distinguish those. The ADV_EXT_IND PDU can be
> distinguished from those despite also being 0b0111 because it's not on a
> secondary advertising channel (ie. not an auxiliary advertisement).
>
> Sultan
>
> On Fri, Jul 10, 2020 at 6:30 PM Guy Harris <gharris () sonic net> wrote:
>
> > For an advertising physical channel PDU, it appears that the PDU type is
> > in the least-significant 4 bits of the PDU header.
> >
> > Is that not present in an auxiliary advertising packet?
>
> --- End Message ---
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