Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 28 Jan 1999 12:09:37 -0800 (PST)
From:      Archie Cobbs <archie@whistle.com>
To:        hm@hcs.de
Cc:        freebsd-isdn@FreeBSD.ORG
Subject:   Re: i4b and netgraph (was: I4B support for US ISDN?)
Message-ID:  <199901282009.MAA03412@bubba.whistle.com>
In-Reply-To: <m105nfo-00006RC@hcswork.hcs.de> from Hellmuth Michaelis at "Jan 28, 99 10:23:40 am"

next in thread | previous in thread | raw e-mail | index | archive | help
Hellmuth Michaelis writes:
> - as long as netgraph is not a standard part of FreeBSD i don't think its
> 	a good idea to move i4b to netgraph.

We hope it will become standard someday... 

> - currently, i4b is relatively self-contained and runs under all BSD's (i've
> 	got even BSD/OS patches for it). Going to netgraph seems to imply
> 	a then necessary namechange from isdn4bsd to isdn4freebsd (or to
> 	package netgraph into the i4b distribution which i don't like at all).

Becoming netgraph compatible does not imply losing the ability
to run in normal mode... doing this would imply some #ifdef NETGRAPH
conditional code though.

> - as far as i understood the netgraph docs, they also use function calls
> 	and _no_ message queues for interlayer communication. So going
> 	to netgraph would not solve the mentioned problem. BTW: i once
> 	asked Terry about the queue/function tradeoffs when that was
> 	discussed on the mailinglist and got no reply.

This is incorrect -- netgraph supports queueing.

> - The ISDN model has a LME (layer management entity) connected to all 
> 	layers using a different path to communicate than the interlayer
> 	communication mechanism, and i learned that implementing this is
> 	a must. I don't see how this is being done using netgraph.

The LME would send and receive the appropriate control messgages
to each of the nodes.

> - More, i currently don't see how the isdnd's functionality is brought
> 	to netgraph.

I'm unfamiliar with what isdnd does.. but there's nothing in netgraph
that you couldn't do from a user mode daemon if you needed or wanted to.

> - To my astonishment, i have read in the netgraph docs that Whistle 
> 	plans to netgraph-enable the i4b ISDN driver code; i wasn't 
> 	aware of that yet since Whistle seem to have its own ISDN stack
> 	and wasn't interested in i4b any longer after a short period of 
> 	interest long time ago.

That wording is misleading.. we don't have any plans to convert i4b.
What I meant was that it would make for a nice project. I'll change
the wording.

> - The last thing i personally need are 2 versions of i4b, one netgraphized
> 	and one not netgraphized.

I don't blame you there :-) Though the differences could be localized
to a few key macros. The message based architecture of ISDN and the
graph nature of netgraph are very similar.

> - There is much more to to do to functionally enhance i4b, to make it more
> 	robust and to fix some bugs in it and i don't have an idea if net-
> 	graphizing i4b brings us more forward with these issues since my
> 	time budget is clearly limited.
> 
> In a word, i'm a bit sceptical.

I respect your priorities.

I think a netgraph version of ISDN would be nice, time and motivation
permitting. I'm not really arguing anything stronger than that.

-Archie

___________________________________________________________________________
Archie Cobbs   *   Whistle Communications, Inc.  *   http://www.whistle.com

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-isdn" in the body of the message



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199901282009.MAA03412>