*BSD News Article 73378


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From: brian@awfulhak.demon.co.uk (Brian Somers)
Newsgroups: comp.unix.bsd.freebsd.misc
Subject: Re: User PPP connection is s......l......o.......w......!
Date: 11 Jul 1996 01:00:49 +0100
Organization: Coverform Ltd.
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Simon Harris (simon@addease.com.au) wrote:
: I have successfully connected to my ISP using user PPP but have found it
: to be very slow in comparison to using PPP under Windows 95. This seems
: odd. In fact I would have expected the reverse to be true.

: Anyone got any ideas? Information I have but I don't really know whats
: relevant.

Have you got a good DTR speed ?  It should ideally be about 4 times your
modem speed - ie 115200 for a 28800 modem, 57600 for a 14400.  If this
is too slow, you modem will overload the UART and you'll lose characters.
Once this starts, you're in trouble.  You end up re-transmitting half
the stuff, lose half of that.......

Another good reason is if you have a crappy IDE disk that likes
interrupting all the time.  Because the IRQ is on the second PIC,
it's *probably* at a higher priority than your UART (disk = 2, UART
= 3/4).  Once you start ftp'ing something, you do disk writes and
start to drop packets on the floor.  The only way I know to circumvent
this is to either buy a better drive (even a SCSI one...) or get your
UART to interrupt on IRQ 2/9.

--
Brian <brian@awfulhak.demon.co.uk>
Don't _EVER_ lose your sense of humour....