/dev/ttyUSB0 and PPP

Wed Feb 22 18:39:43 UTC 2006

On Wed, 2006-02-22 at 10:15 -0800, Harold Hallikainen wrote:
> > On Tue, 2006-02-21 at 19:49 -0800, Harold Hallikainen wrote:
> >> > On Sun, 2006-02-19 at 18:15 -0800, Harold Hallikainen wrote:
> >> >> > I'm trying to set up a ppp connection through my cellphone. I'm
> >> using
> >> >> a
> >> >> USB to EIA232 adapter on FC4_64. I can talk to the cellphone (send AT
> >> >> commands, dial, etc.) from GtkTerm using /dev/ttyUSB0 when logged in
> >> as
> >> >> root. As another user, I get permission denied.
> >> >> >
> >> >> > Desktop/SystemSettings/Network lets me define a modem device on
> >> ports
> >> >> such
> >> >> > as  dev/ttyS0, etc., dev/modem, dev/tty|1, dev/input/ttyACM0,
> >> >> dev/ttyM0,
> >> >> etc. But, no /dev/ttyUSB0.
> >> >> >
> >> >> > So... what do I do to set up a ppp connection on my cellphone modem
> >> on
> >> >> /dev/ttyUSB0?
> >> >> >
> >> >>
> >> >>
> >> >> Still working on this... A google search came up with the suggestion
> >> >> that
> >> >> I add
> >> >>
> >> >> ln -s /dev/ttyUSB0 /dev/modem
> >> >>
> >> >> to my /etc/rc.local . I've done that and am still having trouble
> >> getting
> >> >> ppp to dial out. I'm using the network configure menu
> >> >> desktop/SystemSettings/network. At one point, I could see it dial
> >> just
> >> >> the
> >> >> 1 dialing prefix, but not the rest of the number. Currently, it
> >> doesn't
> >> >> try to dial at all. Instead, I get "cannot connect to network device"
> >> >> when
> >> >> I try to activate it.
> >> >>
> >> >> As root, I can talk to the cellphone using gtkterm. As a non-root
> >> user,
> >> >> I
> >> >> get permission denied. Here's a little more info:
> >> >>
> >> >>
> >> >> [root at hhlaptop ~]# ls -l /dev/modem
> >> >> lrwxrwxrwx  1 root root 12 Feb 19 18:00 /dev/modem -> /dev/ttyUSB0
> >> >> [root at hhlaptop ~]# ls -l /dev/ttyUSB0
> >> >> crw-rw----  1 root uucp 188, 0 Feb 19 18:04 /dev/ttyUSB0
> >> >> [root at hhlaptop ~]#
> >> >>
> >> >>
> >> >> So... any ideas?
> >> >
> >> > Well, the first thing is to change the permissions on /dev/ttyUSB0.
> >> > You need to edit the /etc/udev/rules.d/50-udev.rules and change the
> >> >
> >> >     KERNEL=="ttyUSB*", GROUP="uucp", MODE="0660", OPTIONS="last_rule"
> >> >
> >> > line to read "MODE=0666" to permit world read/write operations, then
> >> > unplug the dongle and plug it back in.
> >> >
> >>
> >>
> >> THANKS Rick! After this change, gtkTerm can talk to the cellphone on the
> >> USB as a non-root user. I then tried the internet connection wizard. It
> >> exits with error 8. Here's what shows up in /var/log/messages:
> >>
> >> Feb 21 19:36:59 hhlaptop ifup-ppp: pppd started for home on /dev/modem
> >> at
> >> 19200
> >> Feb 21 19:36:59 hhlaptop kernel: CSLIP: code copyright 1989 Regents of
> >> the
> >> University of California
> >> Feb 21 19:36:59 hhlaptop kernel: PPP generic driver version 2.4.2
> >> Feb 21 19:36:59 hhlaptop pppd[3187]: pppd 2.4.2 started by root, uid 0
> >> Feb 21 19:37:00 hhlaptop wvdial[3203]: WvDial: Internet dialer version
> >> 1.54.0
> >> Feb 21 19:37:00 hhlaptop wvdial[3203]: Initializing modem.
> >> Feb 21 19:37:00 hhlaptop wvdial[3203]: Sending: ATZ
> >> Feb 21 19:37:05 hhlaptop wvdial[3203]: Sending: ATQ0
> >> Feb 21 19:37:05 hhlaptop wvdial[3203]: ATQ0
> >> Feb 21 19:37:05 hhlaptop wvdial[3203]: OK
> >> Feb 21 19:37:05 hhlaptop wvdial[3203]: Re-Sending: ATZ
> >> Feb 21 19:37:05 hhlaptop wvdial[3203]: ATZ
> >> Feb 21 19:37:05 hhlaptop wvdial[3203]: OK
> >> Feb 21 19:37:11 hhlaptop wvdial[3203]: stdin not read/write and $MODEM
> >> not
> >> set
> >> Feb 21 19:37:11 hhlaptop pppd[3187]: Connect script failed
> >> Feb 21 19:37:12 hhlaptop pppd[3187]: Exit.
> >>
> >>
> >> So, it looks like pppd is being passed device/modem, but wvdial is not
> >> able to communicate with it. I'm guessing the OK entries are the
> >> responses
> >> from the cellphone, so it looks like we're talking to it. So, what's the
> >> line at 19:37:11 mean?
> >
> > Have you edited /etc/wvdial.conf?  You have to set the MODEM variable in
> > the "Dialer Defaults" section of that file.  Something like:
> >
> > 	[Dialer Defaults]
> > 	Modem = /dev/ttyS0
> > 	Baud = 57600
> > 	Init = ATZ
> > 	Init2 = AT S11=50
> > 	Phone = 555-4242
> > 	Username = apenwarr
> > 	Password = my-password
> >
> > Full details are in the wvdial(1) and wvdial.conf(5) man pages.
> 
> 
> THANKS! I'll have a look at that tonight! I was kinda hoping the internet
> connection wizard was indeed a wizard and would know how to set up
> whatever needed to be set up. Also, the various books I have (one being a
> Fedora Core Bible) make no mention of this (just use the wizard!). Google
> searches have led me nowhere (I found a lot about syncing your Palm Pilot
> through USB). 

To be really honest, I haven't used a PPP connection in a LONG time.
I've been on T1s, T3s, DS48s or various broadband connections for over
10 years, so I'm not really up on how the connection wizard works.
Also, I'm an old-time CLI geek and I like to know how the "gears work".
I suppose I should try the wizard and see what's what.

There does seem to be a dearth of detailed information on many Linux
aspects.  I've found a reasonable book that does get into some of the
detail.  It's "Red Hat Enterprise Linux & Fedora Core 4" by Richard L.
Peterson (McGraw-Hill/Osborne, ISBN 0-07-226154-4).  It's not hugely
detailed, but it does contain a lot of the guts.

> So, I REALLY REALLY appreciate all the help you've provided.
> Often when you've answered a question, then that question comes up later,
> I've gone through the archives to find the answer. The Fedora
> documentation project seems, thus far, to be concentrating on
> installation. I hope that it ends up as extensive as wikipedia. So...
> THANKS!

You're welcome.  I try to help as best I can.  I've been puttering
around in the computer field for over 30 years and some stuff has to rub
off on me in that length of time. :-)

I've thought about joining the wikipedia projects, but I never seem to
have the time to participate properly and I think that half-hearted
attempts are often worse than not helping at all.  I keep thinking that
things will calm down here at the office and I'll have time--but there's
ALWAYS another brushfire popping up that needs stomping out.  So, I
answer mail on the list and that's about all I can do for the time
being.

To quote myself,

    "The spirit is willing, but the schedule is a right bitch!"

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- Rick Stevens, Senior Systems Engineer     rstevens at vitalstream.com -
- VitalStream, Inc.                       http://www.vitalstream.com -
-                                                                    -
-     Squawk!  Pieces of Seven!  Pieces of Seven!  Parity Error!     -
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