[Cake] Anybody has contacts at Dropbox?

[Jonathan Morton]

> On 25 Jun, 2023, at 12:00 am, Sebastian Moeller via Cake <cake at lists.bufferbloat.net> wrote:
> 
> Is dropbox silently already using an L4S-style CC for their TCP?

It should be possible to distinguish this by looking at the three-way handshake at the start of the connection.  This will show a different set of TCP flags and ECN field values depending on whether RFC-3168 or AccECN is being attempted.  Without AccECN, you won't have functioning L4S on a TCP stream.

But I think it is more likely that it's a misapplied DSCP.

 - Jonathan Morton