[tcpm] Comment on draft-ietf-tcpm-rack

[Martin Duke <[e-mail]>]

Not a full review, but I may be missing something in this paragraph in
Section 3:

   Using a threshold for counting duplicate acknowledgments (i.e.,
   DupThresh) alone is no longer reliable because of today's prevalent
   reordering patterns.  A common type of reordering is that the last
   "runt" packet of a window's worth of packet bursts gets delivered
   first, then the rest arrive shortly after in order.  To handle this
   effectively, a sender would need to constantly adjust the DupThresh
   to the burst size; but this would risk increasing the frequency of
   RTOs on real losses.

In the "runt" pattern you describe, would not the returning sequence be

Dupack, Ack, Ack, Ack ...

So that any threshold > 1 would handle this with no problems?

Martin