Wireshark-dev: Re: [Wireshark-dev] Patch: Prepare for some cleanups of 802.11ad
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From: Guy Harris <guy@xxxxxxxxxxxx>
Date: Sat, 22 Aug 2015 16:57:04 -0700
On Aug 22, 2015, at 2:30 PM, Guy Harris <guy@xxxxxxxxxxxx> wrote:

> So software that reads radiotap captures and that cares about 11ad information needs to have a workaround wherein frames lacking a DMG field (which means "all frames", currently, as there isn't yet a DMG field) and having a channel frequency in the 11ad range have an 11ad PHY and, if they have MCS or VHT fields, ignore all items in those fields that don't apply to 11ad and *perhaps* interpret the MCS value in the MCS field as if it were an 11ad MCS value rather than an 11n MCS value.

Note that Channel's presence bit index is 3, XChannel's is 18, MCS's is 19, and VHT's is 21, so by the time you see an MCS or VHT field you would already have the channel frequency (if it's present) and thus, if you see an MCS or VHT field, you would already know whether you have an 11ad frame and can process it appropriately.