NetNews Usenet Archive 1992 #19/NN_1992_19.iso/spool/comp/os/linux/9760

Text File | 1992-09-03 | 3.4 KB | 69 lines

Newsgroups: comp.os.linux
Path: sparky!uunet!snorkelwacker.mit.edu!bloom-picayune.mit.edu!daemon
From: [e-mail] (Kevin L. Allred, 615-875-7167)
Subject: RE: Linux-Activists Digest #86
Message-ID: <[e-mail]>
Sender: [e-mail] (Mr Background)
Reply-To: [e-mail] (Kevin L. Allred, 615-875-7167)
Organization: The Internet
Date: Thu, 3 Sep 1992 17:18:36 GMT
Lines: 57

"[e-mail] (Neal Stephenson)" writes:
| Subject: TCP/IP works (yippee) but still some problems : -(

|        I installed the tcp/ip package and it compiled without errors.
| I then increased the number of pty's to 64 and mknod'ed all of them,
| under the assumption that each telnet in used up one (is this right?).
| I then rebooted.
|         I can now ftp out of the system perfectly, it works great and
| since that was the main use, I am very happy (congrats to all
| concerned). :-) :-) :-)
|         However, if I ftp in I hang. Also telnetting out connects to
| the host and then locks up the keys at the password prompt. you can
| however send a ctrl-d to end the login attempt (if it's a unix box) or
| a ctrl-z for a vax, strange.
|        for telnetting in the same kind of problems are encountered.
| if you telnet in to an account that has no passwd (horrible securety,
| i know) it works fine. but if you try one that has a password it locks
| up on the password prompt.
|        last few points. perhaps they are relevant. telneting out is
| very stacatto get packets then nothing then packet. and after telneting
| in when you log out it does not remove the name from the active users
| list.
|        If all of these questions have allready been answered, if
| you could let me know where I can find the answers I'd appreciate it.

| Hardware and software:
|        486/50 16M ram 425M scsi drive 64M & 50M linux minix style
|                partitions and an 8M swap partition.
|        Cardianl ET4000 video card with 1M and Nec 5fg monitor
|        ethernet is a WD8013 on irq 10 I/O 300 mem starting at cc000
|                16K RAM.

I have had very similar experiences (with a very similar setup).  The
system I need to communicate with lies on the other side of a router
and a 56Kbps link.  When I ping my linux system from the remote
computer I see round trip times of (min/ave/max 109/173/746 ms) with a
1% packet loss.  I exchanged mail with Ross Biro about the problem,
and he told me that current linux TCP/IP code doesn't slow down the
rate at which it send packets even when it receives a signal from the
router to do so.  He says that the linux host is probably overloading
the router with packets, thus producing hung connections.  He
suggested a temporary solution that works by cripling the server so it
can't send packets too fast, but I am reluctant to try this approach.

A better approach would be to fix the server so it payes attention to
router signals to slow down.  I looked at the net source code for a
a little while, but it was clear that it is going to take deep
understanding to add this type capability.

Since at one time or another, most everyone who uses tcp/ip will want
to contact a machine at a remote sight, the slow down feature would
seem to be necessary for robust communication.  Are there any network
skilled volunteers willing to try adding this feature?

    Thanks,
    Kevin L. Allred
    [e-mail]