[asterisk-users] Weird (bri)stuff 0.3.0-PRE-1s

Conrad Wood asterisk-users at conradwood.net
Sun Sep 24 08:02:02 MST 2006


>> 2 cents
>
> I would not mind paying a reasonable price for a single port BRI but
> buying a Quad-BRI to get a stable installation is a bit too much for 
> most
> home installations.
>
> Then I will probably start using the old Digital->Analog adapter and 
> use a
> TDM card.
>
> But I don't understand why it shouldn't work with a HFC-S bri card.

The way I understand it is that HFC-S cards are quite dumb and a lot of 
work needs to be done with the main cpu. The ISDN signalling is quite 
sensitive to timing and if the main cpu is busy it's not going to be 
happy.
It also appears that capi/i4l/misdn have a latency far higher than what 
is useful for asterisk. It is aimed at general-purpose use, including 
data transfer. At least, that was my experience.
I tried visdn and the results where very promising but it doesn't seem 
to be quite ready yet. I suspect it's architecture will be much saner 
than bristuff patches.

I also think you get what you pay for and I don't use hfc based isdn 
cards in production any more. Having said that, a small home 
installation isn't quite the same as a 30 user office environment. My 
home-pbx for example is quite happy reloading asterisk+zaphfc every 
night. Of course not something I'd accept in a production environment, 
but that's probably not what HFC-s cards are aimed at either, right?

Conrad



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