Asterisk on FreeBSD + ISDN BRI

[Thomas Wintergerst]

Hi Juha,

Juha-Matti Liukkonen wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> Hi,
> 
> back in the day when I wrote the AVM active card support to i4b, I  
> fantasized about pulling the capi layer up as the kernel-userland  
> interface instead of i4b_layer4; this would have meant implementing a  
> capi-specification-compliant (and AFAIK linux-compatible) /dev/capi20  
> and rewriting isdnd to use it instead of the current i4b* devices. A  
> good part of the necessary support code is already present in the  capi 
> layer (i4b layer4 only registers as one client application for  the 
> somewhat-more-generic capi layer).
> 
> Passive card support would have meant writing a "capi link-layer  
> driver" (a la capi_iavc for the AVM isdn chipsets) for the i4b  passive 
> stack, which hosts the existing passive card drivers. Didn't  seem an 
> insurmountable task at the time. Re-doing isdnd, on the other  hand, did 
> seem like somewhat of an effort.
> 
> I'm not sure what the relevance of this design is any more,  considering 
> that c4b is sort-of doing the same thing, but this way  it'd be 
> reasonably easy to provide a CAPI interface for all i4b- supported 
> passive cards.

In c4b there is already a CAPI driver implementation that is very
similar to one needed for passive boards. The old Diehl ISDN boards (and
also the current Eicon Server boards) provide an interface to D-channel
layer 3 and for data transport. The daic driver has such a CAPI layer
and it is basically working. So one would "only" need a D-channel stack
with a layer 3 interface and some interface to the raw data stream of
the boards. This way one could handle HDLC and voice (transparent)
connections.


-- 
Regards,
Thomas