On Sun, Aug 29, 2010 at 9:19 PM, David Miller [off-list ref] wrote:

From: Jerry Chu <redacted>
Date: Sun, 29 Aug 2010 17:23:05 -0700

quoted

Personally I think as an API, it's easier for an application to
grasp the concept of a time quantity than # of
retransmissions. (E.g., how will an app determine it needs 10
retries vs 20 retries?)

Conversely how can the user grasp how many actual attempts will
be made if backoff is employed?

It's very easy to under-cap the number of actual packet send
attempts that will be made specifying just a timeout, in the
presence of backoff.

My previous statement presumes applications care less about exactly
how many times retransmission attempts have been made because
that's more of "implementation detail" for a reliable transport. But I can
see one can argue either way effectively so I'm ok with both. If people
prefer timeout in # of retries then it just needs to be converted to time
units when used in conjunction with the USER TIMEOUT option (and
one can readily use the existing "retransmits_timed_out()" function,
although the latter presents only an approximation).

Jerry