Re: [MiNT] Modem help

[Guido Flohr <gufl0000@stud.uni-sb.de>]

Hi,

On Mon, Aug 23, 1999 at 11:47:53AM -0400, Katherine Ellis wrote:
> > I only need the modem for pppd (and besides, with Rufus I already get
> > 28800).  But if Rufus is able to connect at 28800 the AT commands should
> > be alright now.  So what do I have to tell pppd to hurry up?
> forget about the at init string for the speed. Only thing you need to
> worry about is the default things, like hardware or software flow control,
> i think with an at&k3 or such. If your modem is hayes compatible, these
> commands should work.

I hope the default settings (I've done at&f) should be alright.  I don't
want to mess around with settings unless I understand them.

> On the web I am sure you can get the command quite easily.
> 1) first test your modem with standard communication program, connect
> rufus whatever, then set the bits, like volume of speaker, timeout, and
> such stupid things :) oh and might wanna check out also the compression in
> there too, but if you did reset it to the default, it should be ok.

OK, maybe I'm just too stupid, let's start before:  I have two sockets
which look like I can put my modem plug in, labeled modem1 and modem2.
I've chosen modem2 more by accident than expertise.  In my
/etc/ppp/options I have

/dev/ttyb
38400

and in mint.cnf:

ren u:\dev\modem2 u:\dev\ttyb

In fact, Knarf has put that line into my mint.cnf. ;-)

In Rufus, for modem2 I can give 38400 which leads to a "CONNECT 28800".
The next setting for modem2 is 73400 which doesn't work.

But 28800 would already be some progress...
 
> 2) the speed connection is made at pppd level, in your .ppprc file add the
> speed in there.
> 
> example:
> 
> debug
> mtu 768
> /dev/modem2
> 57600
> 
> There, just the speed.
> Btw, don't remember if mtu needs the = or not :) i'll check tonight.

Don't worry, my default mtu is alright.

I have

/dev/ttyb
<speed>

For 38400 I get a "CONNECT 19200" from the modem (in /var/log/ppp-log),
higher values give a "speed not supported" from pppd, same for 28800 or
33600.  I then remembered some funny things from the mintnet sources, like
200 would map to 115200 or so.  I then tried it with 50, 75, 110, 134,
150, 200, no reaction from the modem, no atz-click, no dial tone.
300, 600 dialled but could not set up a connection.  Higher values gave
exactly the slow speed I have specified.  Seems like I am stuck with
either 19200 or 38400.

I have learned that there used to be another serial interface which is
hidden behind my graphics card.  This is probably serial1?  According to
Rufus no big loss, highest speed is 19200.

And serial2?  That must be that LAN-Socket on the left, right?  According
to Rufus I could give 57600 for that interface.  Is it worth trying to get
an adapter for it?

> 3) you must try with connect or rufus up to the maximum speed the modem
> doesn't recognize the at commands at all.
> in example, my modem beyond 115k just doesn't want to communicate to the
> falcon (in connect), not even echo the commands back.
> 115k is the limit on mine, 
> Your might be 57600 (computer <-->  modem), maybe higher who knows. 

Highest was 38400 on modem2.

> With having twice or higher the speed of (modem <--> line) compression
> will take effect, (most likely, kinda strange how it works, but well :)
> The higher the better, until connection is affected by your computer load,
> then lower it down. 

Ah, I see.  Do I understand it correctly that I can only benefit from data
compression if I specify a higher speed computer <--> modem than 
modem <--> line so that the modem is kind of "forced" to compress the data
to keep up with the computer?

> Remember, don't load any cpx for serial and all if you are gonna use
> mintnet. Not needed, and mess up things more than anything else.
> As in, you connect and the AES is not loaded.
> fine, then you load the AES, the cpx will kick in automatically, and will
> reset some value, so pppd will work weird, if at all.
> Best to NOT use serial cpx there.
> 
> 4) I am not a specialist, just things i have experienced.

Probably I understood you because you are not a specialist. ;-)
Thanks.

Guido
-- 
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