> 
> > 
> > >Every now and then I dial into my PPP account, I have the line go down and
> > >I get a console message saying something about my serial line being looped
> > >back.  What's it mean and what's causing it?  
> > 
> > I think I had the same problem. pppd tells you that the line is looped, if the
> > modem is offline. I think it reads the CD line from the serial port. Try to 
> > connect to your POP by using cu. Establich a connection and log off from cu. 
> > Remember to setup the modem to stay online when DTR drops. If not it will drop
> > the line while leaving cu.
> > Then you should be able to start pppd without the error message and establish 
> > an internet connection (if your ppp setup is correct ;-).
> > After shutting down pppd, you have to restart cu and hangup the modem.
> > That's the way I got it to work. I even tried to use the chat command as an 
> > connect option to pppd, but it seems, that chat won't work.

I use ppp w/ chat all the time w/o problems. I've got a ppp kit on
puma (version 0.X or so) in my personal directory with both my and
Paul Goyette's configurations. The FAQ section can use some work,
and the modem config string NEEDS TO BE CHANGED FOR YOUR MODEM. I
don't know what your modem needs; please experiment.

Using chat, you don't have to deal with logging in, etc. Just tell
chat your name and password, and you're set. You then just have to type
/etc/ppp/ppp-up, and pppd gets launched to init the connection.

> > Regards
> >         Tobi
> 
> One thing Macs don't do it carrier detect through the CD pin.  You can 
> tinker around with your software and your serial cable to get it to work
> that way.  I know that a Mac BBS called Hermes requires that you do this. 

Au contraire! If your cable works right, they certainly can do
Carrier Detect. The mac ports are brain-dead in that they can't
do both modem hangup and input flow control; they have one output
which can do either. My modem cable is wired for it to do DTR.
The modem's wired so that if DTR drops, it hangs up the modem.

Other hookups, like computer-to-computer, would run DTR to CTS on
the other side, so that we could do flow control (tell the other to
hush up).

Jon,

Your modem config might be a bit off; if you have clocal set for
pppd, then it will ignore the loss of CD. Note: I don't have clocal
set for pppd, but chat does set it (so it can talk to the modem
before there's carrier).

The loopback detection is an integral part of pppd. Rather than turning
it off, I think a better solution would be to make sure pppd sees the
loss of carrier. Also, the current version of pppd can disconnect and
reconnect the lnk after a period of non-use. Maybe it can also reconnect
after hangup. current-users  would know.

> If I'm correct, pppd never uses cu.  It talks directly to the serial port.
> I've gotten chat to work with my pppd with help from Don Woodward (I hope
> that's right; if not, please correct me Don)  :)  It's all in a single
> script.  
> 
> -Jon
>