atom feed10 messages in org.freebsd.freebsd-isdnRe: i4b and netgraph (was: I4B suppor...
FromSent OnAttachments
Hellmuth MichaelisJan 28, 1999 1:23 am 
Barry ScottJan 28, 1999 3:40 am 
Archie CobbsJan 28, 1999 12:01 pm 
Archie CobbsJan 28, 1999 12:09 pm 
Hellmuth MichaelisJan 28, 1999 1:07 pm 
Archie CobbsJan 28, 1999 1:15 pm 
Julian ElischerJan 28, 1999 2:27 pm 
Barry ScottJan 29, 1999 2:47 am 
Jos BackusJan 29, 1999 8:53 am 
Julian ElischerJan 29, 1999 9:25 am 
Subject:Re: i4b and netgraph (was: I4B support for US ISDN?)
From:Archie Cobbs (arc@whistle.com)
Date:Jan 28, 1999 12:09:15 pm
List:org.freebsd.freebsd-isdn

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

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