--- Begin Message ---
On Mon, 2022-05-09 at 12:02 -0700, Guy Harris wrote:
> On May 9, 2022, at 7:41 AM, Tomasz Moń <deso...@gmail.com> wrote:
>
> > That would require defining pseudoheader that would have to be
> > included in every packet.
>
> Is that really a great burden?
I think it would make it harder to understand the protocol for
newcomers that use tools like Wireshark to try to make sense of USB.
> > And it would only solve the corner case that the
> > currently available open-source friendly sniffers do not presently
> > handle.
>
> The point isn't to just handle what currently available open-source
> friendly sniffers handle. I'd prefer to leave room for future
> sniffers that *do* handle it.
>
> > I think it is fine to assume that any tool that would create full-
> > speed
> > captures that contain both full-speed and low-speed data should be
> > able
> > to write pcapng file (or simply create two separate pcap files).
>
> I think that, if you're capturing on a link between a full/low-speed
> host and a full/low-speed hub, with low-speed devices plugged into
> that hub, it would not make sense to treat that link as two
> interfaces, with one interface handling full-speed packets and one
> interface handling low-speed packets; I see that as an ugly
> workaround.
>
> So I see either
>
> 1) a link-layer type for full/low-speed traffic, with a per-
> packet pseudo-header
>
> or
>
> 2) don't support full/low-speed traffic capture, just support
> full-speed-only and low-speed-only traffic capture
>
> as the reasonable choices.
The choice number 2 is essentially what the OpenVizsla does.
--- End Message ---
_______________________________________________
tcpdump-workers mailing list
tcpdump-workers@lists.tcpdump.org
https://lists.sandelman.ca/mailman/listinfo/tcpdump-workers
