🚀 go-pugleaf

In article <EMV.91Jun21004543@bronte.aa.ox.com> emv@msen.com (Ed Vielmetti) writes:
>Chip, could you give a tutorial on compressed batched SMTP ?  That
>would seem to be the ideal thing for long-haul links with high modem
>costs.  How to set it up within smail, what the gotchas are, how much
>of a savings in on-line time there is and at what cost in extra
>compression vs. benefit in fewer uuxes done.
>
>Numbers would be nice to know, if they're convincing we'll start to
>offer the service on our dialups.
>

I will leap in here as well. I run CBSMTP to many sites now, including
decwrl.dec.com. This offers several advantages:

	o	Some sites have expensive/restricted calling times.
		I can defer batching mail to them until this time, and
		collect 20-50 messages in one batch. Compressing on this
		volume of mail is a huge win, with compression ratios of
		3:1 or more. The best savings, however, is the 10 second
		or so UUCP turnaround per file - most CBSMTP links are
		now sitting at 1-2 minute connects (details below).

	o	Proper "smtp"-like addressing. This prevents having to
		whip back and forth between "!" and "@" addressing on
		sites that understand both forms.

	o	Unlimited multi-drop recipients. I run a large mailing
		list from bungi.com, and I get the advantage of having
		a (quite) large list of recipients of one mail message.
		Yes, you can do this with rmail as well (on those sites
		that support this), but it still has the command line
		limit of 1024 characters (or 10K characters, depending
		on your UNIX flavour).

Now, on to numbers. Site cheers.bungi.com is only a hundred or so miles
from daver.bungi.com, so of course it is a hyper-expensive call (within
California). I connect to it only in the wee hours (0100-0600), and queue
mail the rest of the day. Over the past few days, here is the connect
information:

uucp cheers  (6/17-1:27:38,11787,2) OK (conversation complete ttyh2 57)
uucp cheers  (6/18-1:27:17,27604,2) OK (conversation complete ttyh4 65)
uucp cheers  (6/18-6:08:37,307,2) OK (conversation complete ttyh3 145)
uucp cheers  (6/19-1:07:17,9530,4) OK (conversation complete ttyh2 66)
uucp cheers  (6/20-1:07:05,26502,2) OK (conversation complete ttyh2 54)
uucp cheers  (6/21-1:07:12,14722,4) OK (conversation complete ttyh2 61)
uucp cheers  (6/21-3:57:12,16022,2) OK (conversation complete ttyh2 47)

System  # Files  Bytes Rx  Bytes Tx   Connect Rx Avg Rx Max Tx Avg Tx Max TTY
cheers    14            0     47762   0:00:28      0      0   1668   1740 ttyh2
cheers    2             0      2961   0:00:01      0      0   1701   1701 ttyh3
cheers    2             0     22382   0:00:15      0      0   1453   1452 ttyh4

System  # Files  Bytes Rx  Bytes Tx   Connect Rx Avg Tx Avg
cheers    18            0     73105   0:00:45      0   1597

Site Name            Peak         Evening          Night          Total
cheers           0.0  / $0.00   0.0  / $0.00    0.2  / $1.23    0.2 / $1.23  
TOTAL            0    / $0.00   0    / $0.00    0    / $1.23      0 / $1.23  

So far, they have received 264 messages, but I have sent them only 18 files
(9 D. and 9 X. files), totalling 73,105 bytes (compressed), at an average
transfer speed of 1597 bytes/sec, using 45 real seconds of transfering data.
Note that the login overhead/uucp overhead means that we paid for 9 minutes
of connect time, but only used 45 seconds of actual TX/RX. Sigh. Facts of
life.


I suspect that CBSMTP has saved me (this week) over $4. Each uucp transaction
would have taken at least 10 seconds, or about 44 minutes of connect time.
Ignoring the effect of the first minute/subsequent minute charges (which are
considerable - 0.21/0.15 prime, 0.17/0.12 evening, 0.12/0.09 night), this is
8.25 minutes vs 44. $16/month - $192/year. For the cost of a _very_ small
amount of CPU time here to do the compress, and there to do the uncompress.

This is a small example - most of the sites that I talk to do much more mail
traffic than cheers.bungi.com. CBSMTP is a BIG win. I wish everyone would
use it - sun.com for example gets a lot of traffic from daver.bungi.com
via uucp. 1230 files so far, meaning 615 messages so far this week. I bet
the connect time could be at least halved... 9 hours so far this week!

System  # Files  Bytes Rx  Bytes Tx   Connect Rx Avg Rx Max Tx Avg Tx Max TTY
sun       51        55634     13405   0:01:36    626   1094   1773   1900 ttyh1
sun       318       36778   4758207   0:54:49    500    958   1479   1884 ttyh2
sun       80        69188     40373   0:02:52    463   1139   1706   1821 ttyh3
sun       698     1272223   3750093   1:44:37    773   1149    809   1898 ttyh4
sun       83        29018     39527   0:04:57    176    213    296    273 ttyh6

System  # Files  Bytes Rx  Bytes Tx   Connect Rx Avg Tx Avg
sun       1230    1462841   8601605   2:48:54    689   1073

Site Name            Peak         Evening          Night          Total
sun              4.0  / $14.88  2.0  / $5.84    3.3  / $5.64    9.4 / $26.36 
TOTAL            4    / $14.88  2    / $5.84    3    / $5.64      9 / $26.36 
-- 
Dave Rand
{pyramid|mips|bct|vsi1}!daver!dlr	Internet: dlr@daver.bungi.com