[Asterisk-Users] system reboot often?

Rich Adamson radamson at routers.com
Wed Aug 25 05:39:17 MST 2004


> > > If * doesn't like IRQ sharing, how can I scale up a machine with several Zap
> > > card?  Or is it okay to share IRQ's with other Digium cards?
> > 
> > It isn't advisable to have "many" Zap cards in a machine. If you are
> > adding analog cards, you quickly run out of PCI slots before you get
> > very far. If you are adding T1/E1 cards, you quickly get to a point
> > where it is too risky to have that many circuits on a single x86 PC. The
> > whole point of X86 PCs is that they are cheap enough to put several in
> > use when you need it instead of building one behemoth machine.
> 
> Well, we only want 3 TDM400s: 4 FXO and 8 FXS.  That will fit in nearly any
> desktop PC.  That's not the scale that should require multiple boxes.
> 
> But the question is where does the IRQ sharing instability creep in?  I would
> think that *someone* out there would have a * box with 2-4 Digium cards in it
> that might be willing to share their experience.
> 
> If the Digium cards can only be reliably run in a machine with only 1 or 2 of
> them, then I need to know so we can plan appropriately.

The actual number of cards supported in any pc is related to a lot of other
unquantified parameters besides card types. Interrupt latency, PCI bus, etc,
have had a major impact on some motherboards with only a single card installed,
while other systems seem not to be impacted and can have multiple cards installed.

Interrupt sharing can be accomidated, however which cards (and their associated
workloads) are important. The topic cannot be discussed in generic yes/no terms.

I'd have to guess that somewhere near 80% of the * user-list folks are small
soho implementations where the answers to your questions are unknown. Of the
remaining users, I'd also have to guess there are very few that actually have
the technical knowledge/experience to accurately answer your questions since
it seems part of the answer is related to specific motherboards.

The only way to get accurate answers is set up a test system and try it, knowing
there is a high probability you'll need to try several different systems or
motherboards to find the combination that works in your case.






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