On Sun, 15 Jun 2008 Wojciech Puchar <[EMAIL PROTECTED]> wrote: > no i'm not a spammer, but my users often send mails like 20-40MB sized. [..] > something like "T1" here costs far too much to dedicate it just for mails. > > for the same price i can get four "4Mbit/s" ADSL's (which i have now), > that actually gives 4Mbit/s download speed, but only 512kbps upload.
Lucky you. We have a 1500/256kbps link for up to 20 boxes, though there's talk of upgrading to (nominally) 8M/384kbps. > if you substract ACK's needed for 4Mbit/s download, little is left. Slight exaggeration, though TCP downloads do need say 5-10% of download bandwidth upstream. Sure, as soon as you use all upload bandwidth (your mail example, torrents of course, youtube uploads etc) your download bandwidth is shot. Not to mention very soggy remote ssh access :) > my ipfw rules manages all this so web browsing works fine, but mail output > is a problem now. Why not add dummynet pipes and suitable rules to limit the outbound bandwidth for mail (or torrents, whatever's a problem) to a maximum of say 80% of upload, so for 512k set upload limit to maybe 400k, leaving plenty of room for TCP acks? So mail takes a bit longer to send .. You can get fancier with weighted queueing of course, I haven't tried. Works well here anyway, but we're not running a multilink connection. hth, Ian _______________________________________________ email@example.com mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"