[PATCH 0/5] isdn: deprecate non-mISDN drivers

Dang. I forget to reply to the ML once again. Would be easier if the Mails
here vould come from the ML.
2nd try:


Looks like we need to get some facts straight here.

>It turns out that the suggestion from Karsten Keil wa to remove I4L
>in 2018 after the last public ISDN networks are shut down. This has
>happened now (with a very small number of exceptions), so I guess it's
>time to try again.

It has happened? In which marketing department?
Maybe it's no longer of relevance to residential customers.
But for business customers it's quite a different story.
Most of then still use ISDN lines. From the palces I visit, I'd say maybe a
quarter of them have gone VoIP so far. So no sign of an end there.

And last time I checked (which may have been more than two years ago), Versatel
and Vodafone would guarantee to contimue at least up to 2020 / 2023.

>We currently have three ISDN stacks in the kernel: the original
>isdn4linux, the newer CAPI, and finally mISDN stack.

Where mISDN and CAPI can be used in combination.

>As far as I can tell, anyone using ISDN with mainline kernel drivers in
>the past few years uses mISDN, and this is typically used for voice-only
>PBX installations that don't require a public network.

I agree that this is probably the common use case these days

>The older stacks support additional features for data networks, but those
>typically make no sense any more if there is no network to connect to.

They are still there.
And even if they weren't there are always industrial installations that rely
on things that have been obsoleted otherwise.

The main culprit here it, off course, that mISDN has never been a full
replacement for I4L, unfortunately. But that's history.

>My proposal for this time is to kill off isdn4linux entirely, as it seems
>to have been unusable for quite a while. This code has been abandoned

Since when?
I just dug out my old laptop running 4.12 (I fried my current one last week)
to check.
While the card config tools for Icn and Eicon didn't want to compile and
isdnlog was missing some pearl module, the rest compiles and seems to run
fine.
I didn not investigate the compile errors.

Anyway I certeinly use the divertctrl application from time to time.
Much better to carry a USB dongle than a whole telephone that needs setup.
I remember Karsten Keil told once that he started an replacement for mISDN,
but AFAIK that has never seen the light of day.
Also using minicom on an ttyI to quickly make a test call can be quite usefull.

And maybe that idea isn't mainline any more, but I think that the ipppd stuff
and certainly the ttyIs have some educational value.

>for many years and it does get in the way of maintenance.

That is a valid point, off course.
On the other hand having to keep old versions for tasks no longer supported
has become quite a task in itself for some users.

So I think in the end the workload is just shifted elsewhere and the real
issue is coordination of efforts. Which seems be be a huge topic in it's own
right.

Indeed, after I posted that pach recently the question has come up again:
How amy versions of mISDN do actually exist?
Who maintains them? And where?
Is there any coordination going on?
Does anyone actually even care?

And from the technical aspect, I4L and mISDN seem to have quite a bit of
duplicated code. So the ideal situation would be to share those parts.
But off course someone would have to do that.
After I posted the last patch I tried to at least share the USB hardware
definitions, but failed miserably. But then I'm definitely not the C guru.

>CAPI in turn is not quite as obsolete, but as I have been unable to find
>any users, I would suggest moving it to drivers/staging while we

I've never been a fan of CAPI, but AFAIK, the combination of CAPI and hylafax
if the only available implementation of G4 Fax which makes a good argument
for me.
It also seems to be a (partial?) replacement for data connections with mISDN,
but I have never looked in to that.

>If anyone is still using isdn4linux and CAPI with modern kernels, please
>speak up now.

That's mean. You should have asked for OR, not AND. :-)

Not in production, but as stated above I4L is still a valuable tool for me.
OTOH running production machines on older kernels is probably easier than on
a laptop.

  Greetings,
    WIMPy