PPP link throughput

PPP link throughput

Post by Azfar Kazm » Fri, 09 Jan 1998 04:00:00



Hi,

My PPP links do not give throughput of more than 1.5kbps. Is it normal while
copper cable phone lines are being used?

Hardware        :       DEC XL 5100 Pentium/166, 64MB, 3GB, USR Sportster 33.6 external

Software        :       OSE 5.0.0d with net100 and oss499f

My /usr/lib/uucp/Devices entry is:

ACU tty1A - 1200-2400 dialHA24

-Azfar

 
 
 

PPP link throughput

Post by Jean-Pierre Radle » Fri, 09 Jan 1998 04:00:00


Azfar Kazmi telecommunicated (on 08Jan):
| Hi,
|
| My PPP links do not give throughput of more than 1.5kbps. Is it normal while
| copper cable phone lines are being used?
|
| Hardware      :       DEC XL 5100 Pentium/166, 64MB, 3GB, USR Sportster 33.6 external
|
| Software      :       OSE 5.0.0d with net100 and oss499f
|
| My /usr/lib/uucp/Devices entry is:
|
| ACU tty1A - 1200-2400 dialHA24

What baud do you use between the computer and the modem,
at what baud does the modem connect to your ISP, and are
you using hardware flow control?

--


 
 
 

PPP link throughput

Post by Azfar Kazm » Sat, 10 Jan 1998 04:00:00



> What baud do you use between the computer and the modem,
> at what baud does the modem connect to your ISP, and are
> you using hardware flow control?

Let me clarify what actually I am doing. I have an OSE 5.0.0d running. We have
a couple of departments some 12 miles away from us. They need to do on-line
data entry in this SCO Box [which is an Ingres database server.] I provided
remote users with the PPP dynamic incoming links. They are using it via,
ofcourse, phone lines with Win95 PCs. The problem is that they keep complaining
about the speed. Which *is* quite slow.

I need to augment the transfer speed. I believe it is due to the copper cables
being used by the phone company. I am looking for solutions.

As far as the baud rate of Win95-Modem is concerned, it is 57600. The SCO-Modem
baud is 2400 [/usr/lib/uucp/Devices]. The connection establishes at 28.8 or
33.6 kbps. And the flow control is, yes, hardware i.e. rcscts.

-Azfar

 
 
 

PPP link throughput

Post by Tom Parson » Sat, 10 Jan 1998 04:00:00


Azfar Kazmi enscribed:
|
| > What baud do you use between the computer and the modem,
| > at what baud does the modem connect to your ISP, and are
| > you using hardware flow control?
|
| Let me clarify what actually I am doing. I have an OSE 5.0.0d running. We have
| a couple of departments some 12 miles away from us. They need to do on-line
| data entry in this SCO Box [which is an Ingres database server.] I provided
| remote users with the PPP dynamic incoming links. They are using it via,
| ofcourse, phone lines with Win95 PCs. The problem is that they keep complaining
| about the speed. Which *is* quite slow.
|
| I need to augment the transfer speed. I believe it is due to the copper cables
| being used by the phone company. I am looking for solutions.
|
| As far as the baud rate of Win95-Modem is concerned, it is 57600. The SCO-Modem
| baud is 2400 [/usr/lib/uucp/Devices]. The connection establishes at 28.8 or
| 33.6 kbps. And the flow control is, yes, hardware i.e. rcscts.

Of course it is slow.  You have your serial port set for 2400 baud.  Change
the baud rate in /usr/lib/uucp/Devices to 38400 and make the appropriate
changes in /etc/inittab, your atdialer and /usr/lib/uucp/Systems.
--
==========================================================================

==========================================================================    

 
 
 

PPP link throughput

Post by Azfar Kazm » Wed, 14 Jan 1998 04:00:00



> Of course it is slow.  You have your serial port set for 2400 baud.  Change
> the baud rate in /usr/lib/uucp/Devices to 38400 and make the appropriate
> changes in /etc/inittab, your atdialer and /usr/lib/uucp/Systems.

I will be appreciate if you could let me know specifically what chnged I hav to
mke?

Currently, I have following entries:

/usr/lib/uucp/Devices
ACU tty1A - 1200-2400 dialHA24

/etc/inittab
Se1A:234:respawn:/etc/getty -t60 tty1A 3

/etc/conf/init.d/sio
Se1A:234:respawn:/etc/getty -t60 tty1A 3

I looked throught he dialers I have and the swiftest I found is dialHA96V! Not
of 38400!

Thanks a lot.

-Azfar

 
 
 

PPP link throughput

Post by Tom Parson » Wed, 14 Jan 1998 04:00:00


Azfar Kazmi enscribed:
| > Of course it is slow.  You have your serial port set for 2400 baud.  Change
| > the baud rate in /usr/lib/uucp/Devices to 38400 and make the appropriate
| > changes in /etc/inittab, your atdialer and /usr/lib/uucp/Systems.
|
| I will be appreciate if you could let me know specifically what chnged I hav to
| mke?
|
| Currently, I have following entries:
|
| /usr/lib/uucp/Devices
| ACU tty1A - 1200-2400 dialHA24

ACU tty1A - 38400 {name_of_an_appropriate_dialer}

| /etc/inittab
| Se1A:234:respawn:/etc/getty -t60 tty1A 3
|
| /etc/conf/init.d/sio
| Se1A:234:respawn:/etc/getty -t60 tty1A 3

Assuming you haven't modified the original /etc/gettydef, change "3" to "o".

| I looked throught he dialers I have and the swiftest I found is dialHA96V! Not
| of 38400!

Don't use dialers, create your own atdialer script with
/usr/lib/uucp/make.dialer or even easier, modify one of the existing
scripts.  

Caveat:  Always create a new file with make.dialer, do NOT try to modify
an existing file.  By this I mean, do not ever do "make.dialer {filename}".
--
==========================================================================

==========================================================================    

 
 
 

PPP link throughput

Post by Azfar Kazm » Thu, 15 Jan 1998 04:00:00



> Assuming you haven't modified the original /etc/gettydef, change "3" to "o".

No. I haven't.

Quote:> Don't use dialers, create your own atdialer script with

Is it really needed? I don't dialout. I just have to serve dial-in links?

-Azfar

 
 
 

PPP link throughput

Post by Tom Parson » Thu, 15 Jan 1998 04:00:00


Azfar Kazmi enscribed:
|
| > Assuming you haven't modified the original /etc/gettydef, change "3" to "o".
|
| No. I haven't.
|
| > Don't use dialers, create your own atdialer script with
|
| Is it really needed? I don't dialout. I just have to serve dial-in links?

I would not have mentioned it if you didn't need one or at least given
you an alternative.  Everytime getty cycles on a modem port, it attempts
to re-initialize the modem with the parmeters in the file named in the
dialer field for the first entry for that port in /usr/lib/uucp/Devices.

This is in the documentation, BTW.
--
==========================================================================

==========================================================================    

 
 
 

PPP link throughput

Post by Azfar Kazm » Fri, 16 Jan 1998 04:00:00



> > /usr/lib/uucp/Devices
> > ACU tty1A - 1200-2400 dialHA24

>  ACU tty1A - 1200-38400 dialHA24 \D
>                          ^^^^^          ^^    
> > /etc/inittab
> > Se1A:234:respawn:/etc/getty -t60 tty1A 3

>  Se1A:234:respawn:/etc/getty -t60 tty1A o
>                  change to the letter "o"  ----^

> > /etc/conf/init.d/sio
> > Se1A:234:respawn:/etc/getty -t60 tty1A 3

>  Se1a:234:respawn:/etc/getty -t60 tty1A o
>                  change to the letter "o"  ----^

I did the same without any success. After these changes, I *do* get the
connection but not the *not* the login! Instead some wierd characters appear!!
Even, when I changed back to my previous settings, I was not getting login
prompt until I had to restart the whole system! Do I have to restart whenever I
make any change(s) in inittab and sio?

-Azfar

 
 
 

PPP link throughput

Post by Azfar Kazm » Fri, 16 Jan 1998 04:00:00



> ACU tty1A - 38400 {name_of_an_appropriate_dialer}

Don't I have to give the range? E.g. 1200-38400? BTW, when I give 38400, the cu
says that its a 'bad speed 38400'

Quote:> Assuming you haven't modified the original /etc/gettydef, change "3" to "o".

I did. What I then received at login prompt was wierd characters! I then
changed back to my previous settings. What am I doign wrong?

Please see my other post on this subject sent to the newsgroup.

-Azfar

 
 
 

PPP link throughput

Post by Azfar Kazm » Fri, 16 Jan 1998 04:00:00



> Is there a chance you are getting the raw ppp data coming out of the
> computer and into the terminal ?!  If you are running a ppp link is there
> a chance you are getting the ppp ?
>  To update the baud rates by changing the letter, simply disable
> the ports first before editing.  IE: disable tty1a  & disable tty1A, note
> the difference with the upper and lower case letter "A".
>  Then enable tty1A for a port with the hardware control, meaning
> the DTS anc DCE and such are active, this enables the computer to dump the
> connection if the modem is hung up.
>  Enabling tty1a (lower case a) is a standard communications port
> without the help of the hardwire control.  This is used for direct
> connections to a another pc, without a modem between them, just like
> hooking up a cable from the communications port of one to the other.
>  The strange letters could also be wrong baud rate, and possiblity
> of parity error, one of them is looking for no parity and the other is
> sending even.   If possible insure both ports are at the same speed and
> same configuration.  I used the N-8-1 theory here, meaning No parity 8
> bits for word structore, and 1 stop bit.
>  Otherwise I can't think of anything else that might produce
> strange letters at all baud rates just shy of a defective serial port in
> either machine.

Obviously, there are not many files to change. There are only two: inittab and
sio. So I disabled tty1A [the one I am using] and then after changes have been
made I enabled tty1A.

The port is okay as it is working at 2400 baud rate. Is it necessary to reboot
the system after these changes? I had to do it when I changed my settings back
to the previous ones!

--
Azfar Kazmi
http://www.comports.com/azfar

 
 
 

PPP link throughput

Post by Tony Lawrenc » Fri, 16 Jan 1998 04:00:00



> > Assuming you haven't modified the original /etc/gettydef, change "3" to "o".

> I did. What I then received at login prompt was wierd characters! I then
> changed back to my previous settings. What am I doign wrong?

You aren't setting your modem to a fixed DTR.

How to do this depends on the brand of the modem, but for
most Hayes compatibles, you want to cu to the port
at the 38400 speed, and type AT&B1, then AT&W (or W0 on
some modems).

For excruciating details, see the article on Configuring
High Speed Modems at http://www.aplawrence.com/unixarticles.html

--

SCO ACE
Microsoft MCSE
http://www.aplawrence.com

 
 
 

PPP link throughput

Post by Tony Lawrenc » Sat, 17 Jan 1998 04:00:00




> > Assuming you haven't modified the original /etc/gettydef, change "3" to "o".

> No. I haven't.

> > Don't use dialers, create your own atdialer script with

> Is it really needed? I don't dialout. I just have to serve dial-in links?

Yes, no, maybe and of course.

Strictly speaking, you do not need anything in /usr/lib/uucp/Devices
for a dial-in line to work.  However, getty does *use* information
from that file to reset the modem after a session, so you may
*want* to have an entry there.

However, my approach to these things is to work from simplicity:
get the most basic things working, and then build from there.  I
often have to deal with people who have non-functional modems,
and what I want to do is just get it working at a basic level
so that I can dial in and do more.  In your case, you want to
get it working at a basic level so that you can have a working
starting place, to which you add more functionality.

So, my suggestion is to start by forgetting about PPP.  Yes,
you want inbound PPP, but you need a working dial-up login
first.

Second, clean out /usr/lib/uucp/Devices. Copy it to a Devices.safe
first, and then use vi, and do "1,$s/^/#/".  This will comment out
EVERYTHING, so there is no possibility of a conflict, getty can't
possibly reset you to some unexpected value, and you are starting
fresh.

Now add ONE line to the very top of the file:

Direct tty1a - 38400 direct

Note that's a LOWER-CASE a.

Now disable the port:

disable tty1a
disable tty1A

One or both of these may say "already disabled"; that's OK.

Now cu, using:

cu -ltty1a dir

(that's minus-ell and tty-ONE-a)

Issue the appropriate command to set your modem to fixed DTR.  For
most Hayes clones, including US Robotics, that's AT&B1.  It's
possible that you may want other settings (you certainly
cannot ignore S0, for example), but the idea here is to keep
it SIMPLE.  You can worry about flow control and everything
else later.  We just want a login.  Get that, and the rest
can be added in stages.

Now edit /etc/inittab and change the tty1A (upper case) to have
"o" at the end of the line.  Again, there are better things
we can do involving new entries in /etc/gettydefs, but we
just want to get it working.  Don't bother with /etc/conf/init.d/sio
for now, but do remember to come back to that later.

Finally, enable tty1A (upper case). Dial in using another machine.
If you DO NOT get a garbage free login, start over again with 19200
and "n" instead.  Modern equipment should not have to do this,
but real crappy old stuff might even have to drop to 9600.  That's
still better than the 2400 you are using now, though.  

Again, please see the article at
http://www.aplawrence.com/unixarticles.html entitled "High Speed
Modems" for more information and details.

--

SCO ACE
Microsoft MCSE
http://www.aplawrence.com