Re: [PATCH v6 net-next 0/2] tcp: Redundant Data Bundling (RDB)

Jonas Markussen
2016-03-10T02:02:15Z

> On 10 Mar 2016, at 01:20, Yuchung Cheng <ycheng@google.com> wrote:
>
> PS. I don't understand how (old) RDB can masquerade the losses by
> skipping DUPACKs. Perhaps an example helps. Suppose we send 4 packets
> and the last 3 were (s)acked. We perform RDB to send a packet that has
> previous 4 payloads + 1 new byte. The sender still gets the loss
> information?
>

If I’ve understood you correctly, you’re talking about sending 4
packets and the first one is lost?

In this case, RDB will not only bundle on the last/new packet but also
as it sends packet 2 (which will contain 1+2), packet 3 (1+2+3)
and packet 4 (1+2+3+4).

So the fact that packet 1 was lost is masqueraded when it is
recovered by packet 2 and there won’t be any gap in the SACK window
indicating that packet 1 was lost.

Best regards,
Jonas Markussen