ppp: a couple of questions, if you please.

Hi all,

Back when we used to use sco openserver boxes, it was very easy to
connect them to each other (both ways) using normal external analog
modems demand dial ppp with idle time setting to drop the connection
and either host could initiate dial and bring up the link.

In Linux (RH/Fedora) I tried to set it up using /etc/ppp/ip-up.local to
set up and take out routes but couldn't really make it work reliably.
Can someone please point me to an easy step-by-step procedure to set up
such a thing?

It gets into dial-busy deadlock when both hosts try to dial each other
simultaneously when there is only one modem on each host assigend for
this. But it could happen to SCO as well.

However in SCO, we could set up multiple modems in uucp/Devices file
and their dialer could automatically use the next available modem to
dial out. As regards to dial-in, we could ask the phone company for a
pilot number that could be answered by the next available line in the
group.

The answering part would work in Linux as well. How can we make the
dialer (wvdial or some) to use the next available modem?

SCO uses uucp to connect ppp calls. Is it possible to do the same in
Linux or is there a better way?

Thanks and regards.
J Dubal.

dubal wrote:
> Hi all,
>
> Back when we used to use sco openserver boxes, it was very easy to
> connect them to each other (both ways) using normal external analog
> modems demand dial ppp with idle time setting to drop the connection
> and either host could initiate dial and bring up the link.
>
> In Linux (RH/Fedora) I tried to set it up using /etc/ppp/ip-up.local to
> set up and take out routes but couldn't really make it work reliably.
> Can someone please point me to an easy step-by-step procedure to set up
> such a thing?
>
> It gets into dial-busy deadlock when both hosts try to dial each other
> simultaneously when there is only one modem on each host assigend for
> this. But it could happen to SCO as well.
>
> However in SCO, we could set up multiple modems in uucp/Devices file
> and their dialer could automatically use the next available modem to
> dial out. As regards to dial-in, we could ask the phone company for a
> pilot number that could be answered by the next available line in the
> group.
>
> The answering part would work in Linux as well. How can we make the
> dialer (wvdial or some) to use the next available modem?
>
> SCO uses uucp to connect ppp calls. Is it possible to do the same in
> Linux or is there a better way?
>
> Thanks and regards.
> J Dubal.
>

Hello,

if I understand it the right way. Your problem is, that you have several
modems on your machine and what to use the next free modem for the a new
outgoing demanded connection ?

Dial on Demand should be done with the connection timeout parameter in pppd.

The used lines maybe available in lockfiles written by the pppd. The
last time i did care about ppp-connection is some years ago. But I will
try to help you.

BR
Hans-Juergen Lange

dubal <(E-Mail Removed)> wrote:

> Back when we used to use sco openserver boxes, it was very easy to
> connect them to each other (both ways) using normal external analog
> modems demand dial ppp with idle time setting to drop the connection
> and either host could initiate dial and bring up the link.

> In Linux (RH/Fedora) I tried to set it up using /etc/ppp/ip-up.local to
> set up and take out routes but couldn't really make it work reliably.
> Can someone please point me to an easy step-by-step procedure to set up
> such a thing?

That's a bit vague but...

1. Use the full path name for route and ifconfig.
2. Take down any routing to be replaced.
3. Setup the replacement routing.
4. Bring up the downed routing in /etc/ppp/ip-down.

(Perhaps /etc/ppp/ip-{up,down}.local would work the same way but those
are fluff created by some distributors - I've never been sure why.)

For example, if pppd is set up for demand dialout using the PPP
interface ppp0 and a PPP interface is brought up in another way then,
to replace the demand default route with one to the new interface's
remote IP address, put

/sbin/route del default ppp0
/sbin/route add default gw $IPREMOTE $IFNAME

in /etc/ppp/ip-up, and to restore demand capability, put

/sbin/route add default gw 10.112.112.113 dev ppp0

in /etc/ppp/ip-down, assuming the demand option's default remote IP
address, 10.112.112.113, is used by the ppp0 interface.

The reason for deleting and restoring the demand default route rather
than depending on a new default route overriding the old is that when
I tried it (quite awhile ago) just overriding seemed to bugger routing
- YMMV.

> It gets into dial-busy deadlock when both hosts try to dial each other
> simultaneously when there is only one modem on each host assigend for
> this. But it could happen to SCO as well.

As is true for any OS.

> However in SCO, we could set up multiple modems in uucp/Devices file
> and their dialer could automatically use the next available modem to
> dial out. As regards to dial-in, we could ask the phone company for a
> pilot number that could be answered by the next available line in the
> group.

> The answering part would work in Linux as well. How can we make the
> dialer (wvdial or some) to use the next available modem?

I've never used it but the pppd RADIUS plugins, radius.so, radattr.so,
and possibly radrealms.so, might provide a solution. Check the man
pages in the pppd/plugins/radius directory of the pppd 2.4.3 source.

> SCO uses uucp to connect ppp calls. Is it possible to do the same in
> Linux or is there a better way?

Not sure, never used uucico. Maybe mgetty?

--
Clifford Kite Email: "echo xvgr_yvahk-(E-Mail Removed)|rot13"

Many thanks for the replies.
I will do some homework based on these and get back here.
Regards.
J Dubal.