[lug] Dialup modems and Linux

[D. Stimits]

Justin-lists wrote:
> I have been forced to go back to dialup after moving into our new house. I 
> didn't think it would be such a nightmare. I used dialup with linux years 
> ago, but I don't remember exactly how I did it. I think I used minicom to 
> dialup then manually activated pppd. Anyhow, I've been trying for 3 days off 
> and on to get this working and I have gotten absolutely nowhere. My modem 
> works fine in Windows, no problem. But I cannot get things to work in Linux. 

If it is a winmodem, you will have problems, though some of the 
winmodems now seem to have drivers.

> 
> First modem attempt, an old isa Cardinal 56k modem. Works ok in windows on 
> com2. I put it in my linux box and link /dev/modem to /dev/ttys1. Minicom 

Lower case "ttys1" does not exist. Did you mean "ttyS1"?

> can see the modem and I can get tone with it and actually dial my isps 
> number. But as soon as the "connection" tones (you know, the (in)famous 
> modem tone) go away I can hear the modem hang up, and I get nowhere, logs 
> show me nothing. I tried using wvdial as well with no luck. Wvdialconf tells 
> me there is no modem found, great. I found this tool from Redhat 
> called "redhat-config-network", it also tells me no modem found when I probe 
> for modems, yay. Have I mentioned that I hate dialup w/ a passion yet? 

Perhaps PAP or CHAP authentication is used. cd to /etc/ppp/ (I am 
assuming Redhat, but many others use this same directory), and look at 
files "pap-secrets" and "chap-secrets". Most ISP's will use PAP, and it 
won't hurt to fill in both pap- and chap-secrets, even if they are not 
used. Failing PAP will result in connecting then getting hung up on. 
Failing CHAP might result in that, but if you do connect for a bit, a 
later challenge will still dump you. Make these files readable only by 
root, though the directory and some of the files will be readable by 
anyone. Assume your pass is "pass", name for login is "name", add 
something like:
name * pass

Both chap and pap files use the same thing. Try again, I highly 
recommend wvdial.

> 
> Modem number 2. I decide to get a modem that was built within the last 5 
> years or so. So I go buy a creative labs pci modem in hope that linux would 
> actually recognize teh hardware, being it a pci device and not isa. So, I 
> plug the new modem into the Linux box. Wow, kudzu found it! Kudzu went 
> through and "configured" teh modem, but I couldn't really tell what it did 
> exactly. I got booted back up and went to try wvdial again. I ran 
> wvdialconf....no modems found again?? I ran redhat-config-network and probed 
> for modems, no modems found...I tried linking /dev/modem 
> to /dev/ttyS0, /dev/ttyS1, /dev/cua0, /dev/cua1, etc just to see if I could 

cua devices are no longer used, ignore them. What about ttyS2 and ttyS3?

> get anything to budge. I could get nothing to work. Also, I could not even 
> get minicom to see the new modem. No tone or anything, so I am actually in 
> worse shape with the new modem than I was with my ancient isa modem. How can 
> I get linux to see this !E@$#@% modem?

Some winmodems will be found, and even configured. You might even get 
them to dial, but then they act stupid and do nothing. Don't know if 
those are winmodems. However, there is a twist here, you are using PCI. 
Is your BIOS set to "o/s is NOT plug-n-play compatible"? If not, there 
is your likely problem. PCI devices, when they boot, do not have a set 
irq or port address. Either the o/s or the BIOS must set the values. If 
you have the BIOS set that o/s IS pnp-aware, then it will not help you. 
Better set it to NOT pnp-aware, and let the BIOS set it. Where PCI is 
concerned, just because it is COM2 in windows (ttyS1), you do not know 
that this value will remain, *unless you boot via loadlin*, which saves 
the state of hardware and overwrites windows. You can be guaranteed your 
ISA modem will not change on you, unless it is a plug-n-play ISA 
modem...in which case software is mandatory to set it, the BIOS probably 
can't help.

> 
> Ugh, I have been through many linux dialup howto's and the linux ppp howto 
> (which I think went out of date in the late 90's!) many times. I am giving 
> up at this point because I have no clue as to what to do next. I am so 
> frustrated trying to get a stupid modem to work. And for what? When I 
> finally do get this working, I'll have a mean 56k connection to serve my 6 
> computers at home, UGH! Somebody please bring me broadband!!!!
> 
> Oh yea, anyone have any ideas on this? :)

Start with /etc/ppp/pap-secrets and chap-secrets. Reboot, and as you get 
to BIOS setup, be certain you are NOT o/s being pnp-aware. When fully 
booted, look at /proc/pci, and attempt to identify your device. ID will 
not necessarily be easy, it could possibly be listed (as with many 
non-modems) as a serial controller. If it has the manufacturer name, you 
are a step ahead. I forget which io address goes with which port, but if 
you still can't get it to work after manually linking /dev/modem to 
ttyS0 through ttyS4 (ignore one if you know something else is on the 
port), you can post the io address and it can be compared with other 
docs to be sure which port it is on.

Also, you might find "lspci" and "lspci -v" (or even "lspci -vvv") to be 
useful if more info is needed.

D. Stimits, stimits AT attbi.com