Subject: [core] Draft (C. Bormann): CoAP Simple Congestion Control/Advanced

From: "Ekaterina Dashkova" <[email-masked]>
Date: Sun, 26 Aug 2012 21:31:10 +0300

Hi,

  Thank you for the draft, but I would like to propose a number of
questions/comments for discussion:

1)      I have difficulties to understand sentence: "A client that has
arrived at a RTT estimate much shorter than the 2 to 3 s used as a default
SHOULD therefore not expend all of its retransmissions in the shorter
estimated timescale" 

-   Should it be ". has received a packet ." instead of ". has arrived ."
-   In part ". RTT estimate much shorter than the 2 to 3 s ." - If we say
"much shorter" then just 2s boundary is important for the statement. So I
would propose to replace it by just ". much shorter than 2 s ."
-   Most important - I had difficulties to understand the main point of this
sentence. Now it sounds as a self-evident statement, or some important
message is missing (i.e., I haven't get it).
 
2)      I had a lot of difficulties to understand proposal on blind RTO
estimation, i.e. in the sentence "Up to four (4) exchanges to an endpoint
can be started in parallel. If only the initial RTO estimate is available,
the RTO estimate for each exchange started in parallel to other exchanges is
set to the highest binary multiple of the parallel exchanges, e.g., if
another exchange is already running and is into its second retransmission,
the RTO estimate for the additional exchange is 8 seconds."
-   The provided description is a bit fuzzy (e.g. could we take the number
itself as a highest multiplier, as formally mathematically it can be the
case), so I would propose to replace the description by formula and set of
formal rules.
 
     Also there is a number of small spelling errors. Could we agree a
process to report such issues?
 
Best wishes,
Ekaterina Dashkova