Summary: PPP with modems on terminal servers...

From: Randy Zagar (
Date: Wed Oct 19 1994 - 10:49:58 CDT

Earlier this month I posted a question about using Solaris' PPP
software with a bank of modems that I can access across the network.

I only got one reply on this one. Only one person said that they
were able to configure a working PPP with a bank of network-accessible


I'm including his comments, as it seems they had to modify the software
some to make it work. The problem (with streams) is that the lowest level
serial i/o stream module (zs) understands ioctls and the lowest-level
stream module for pseudo ttys do not. Here's what he had to say:

> We have installed dp-3.2.1. However, we had to
> change the code to get it to work. The following happens. The user
> logs in via a pseudo terminal and gets a PPP "shell". The shell pops
> all stream modules from the stream. Then it does a ioctl(TCGETS,..).
> This fails when the user logged in via a pseudo terminal. In this case
> the stream looks like (strconf(1)):
> ttcompat
> ldterm
> ptem
> pts
> After popping, only pts remains. Pts does not recognize ioctls, ptem
> does. So we changes the code such that ptem will not be popped.

> In the case of a serial port the stream looks like:
> ttcompat
> ldterm
> zs
> After popping, zs remains and zs handles ioctls. It is my guess Sun's
> PPP has the same problem.

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