Re: off topic? out of office

At 9:21 PM +0000 11/20/01, Jonathan Chetwynd wrote:
>can anyone tell me how it is that I frequently get oof replies long before I
>see the message I posted?

A message from you goes:

You --> Server --> Everyone

The first loop, the out-of-office loop, goes like this:

You --> Server --> Someone else --> You

The second loop, your own copy of what you posted, goes:

You --> Server --> You

Now, the tricky part is that the transmission from Server -->
Everyone might not happen instantly.  For example, if you are
at the bottom of the distribution list, and I'm at the top, I
might get my mail long before you get yours.

An illustrative timeline:

:00  Jonathan sends email to the list.

:01  Jonathan's email is received by the server.  The list server
      starts sending out copies to everyone on the list.

:02  Kynn's name, 3rd on the list, is reached, and email is sent
      to Kynn.  The server continues on down the list of subscribers.

:03  Kynn's server receives the email.  Kynn's "out of office"
      program sends email directly to Jonathan.

:04  Jonathan's mail host receives Kynn's "out of office" email.

:07  The list server, continuing to send email, gets down to
      Jonathan's address, near the end.  It sends a copy to him.

:08  Jonathan receives his own copy of the email.

:10  The list server finishes sending copies out.

That's just one way it could happen.  Another way is that email
delivery between points on the internet is not a constant amount
of time; it varies a lot depending on speed of connection and
network traffic.  So another scenario could be:

Jonathan sends his email to the server.  It takes 5 seconds to
get there.  The server holds on to it for some amount of time
(see above) and then sends it out again.  It takes 1 second to
deliver the email to Kynn.  And it takes 2 seconds for a message
to go from Kynn to Jonathan.  So it arrives in 3 seconds, while
Jonathan's copy took 5 seconds to reach him.

The two scenarios aren't incompatible -- and in fact, both are
likely at work here.  To factor the second scenario into the
first, you just have to adjust the timeline for the amount of
time it took to transmit the message.  In the first scenario,
the transmission time is assumed to be a constant 1 second
instead of a variable amount.

--Kynn

-- 
Kynn Bartlett <kynn@idyllmtn.com>
http://www.kynn.com/

Received on Tuesday, 20 November 2001 16:52:26 UTC