STRING and BOS Descriptors not visible

[Janet Pittock]

I have installed USBPcap and wireshark - latest versions, but cannot see any packets relating to BOS descriptor or STRING descriptor events.

I know the device is sending these and the PC must be getting them as it translates the string indexes to strings - but the actual transfers are not showing up in wireshark.

I'm using Windows 10 - this problem applies to all devices I've plugged in.

Am I looking at a USBPcap problem or a wireshark issue?

[Tomasz Moń]

On Sun, Jan 16, 2022 at 4:28 PM Janet Pittock <jmpitt...@gmail.com> wrote:
> I have installed USBPcap and wireshark - latest versions, but cannot see any packets relating to BOS descriptor or STRING descriptor events.

Wireshark currently does not dissect BOS descriptors. This is apparent
when you have hardware level capture (OpenVizsla).

> I know the device is sending these and the PC must be getting them as it translates the string indexes to strings - but the actual transfers are not showing up in wireshark.

STRING descriptors can be cached.

> I'm using Windows 10 - this problem applies to all devices I've plugged in.
>
> Am I looking at a USBPcap problem or a wireshark issue?

If you had a capture with BOS descriptor, it'd appear in Wireshark as
not yet dissected. The not dissected is Wireshark issue, not capture
at all is USBPcap issue.

The ultimate way to tell if the device queries the STRING descriptors
is to capture with hardware sniffer and compare with USBPcap capture.
The BOS descriptor for sure is missing from USBPcap captures and I am
unsure if it can be captured at all using current approach.