Re: [Asterisk-Users] PCI front mount chassis?
On Fri, 12 Mar 2004, Brian Capouch wrote: I too am running 6 cards in my system, although not in a high traffic capacity load environment. So far my (limited) high-load simulations have shown no problems. So - is it apocryphal that the Digium cards (drivers) won't share interrupts? If there is a real issue with sharing interrupts then it seems to me to be a bug that needs fixing. PCI bus supports shared interrupts, why doesn't the hardware/driver? Yours curiously, Steve ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] PCI front mount chassis?
I too am running 6 cards in my system, although not in a high traffic capacity load environment. So far my (limited) high-load simulations have shown no problems. So - is it apocryphal that the Digium cards (drivers) won't share interrupts? If there is a real issue with sharing interrupts then it seems to me to be a bug that needs fixing. PCI bus supports shared interrupts, why doesn't the hardware/driver? In most cases, sharing an interrupt is not a problem at all. There have been a few cases where _some_ issue was resolved by moving cards around, however the majority of those seem to be: a) abrupt system changes with no effort to seriously identify the root-cause, b) newbie installations where the condition of the underlying system infrastructure is totally unknown, or, c) wild recommendations that might have had some basis a long time ago but no longer apply. Example: 'cat /proc/interrupts' 9: 1854652239 XT-PIC ehci-hcd, eth0, wcfxo, Intel ICH4 works just fine, and I can't imagine a more demanding irq arrangement where the only nic shares with an x100p, etc. Obviously there are performance limits and expecting multiple quad T1 cards or some other _specific_ high-volume configuration to share one or two interrupts could create a problem. But, engineering a system for those conditions is no more difficult then understanding the requirements of whatever cards are being used and dealing with them appropriately. ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] PCI front mount chassis?
Wow, 1000 IRQs a second. I'm quite amazed. Does anybody know which applications would require such a low latency ? It does seem to me that this way of doing things is rather dangerous and prone to problems. Anybody can comment ? Thanks Bruno Nicolas Bougues wrote: On Fri, Mar 12, 2004 at 08:41:36AM -0500, Walt Reed wrote: The voice cards generate an order of magnitude more interrupts than anything else. This may be why it's not recommended to share interrupts on voice cards. Don't know if the T1 cards have a similar issue. I would hope not. The x100p's are a pretty simplistic device. They probably generate an interrupt for every byte. The x100p's are also used for timing in things like MOH and MM conferences AFAIK. It seems like it would be nice to only put one card in timer mode if that is indeed what is generating all those interrupts. Could someone in the know enlighten us? Digium boards usually generate 1000 interrupts/sec. This is mostly a timer interrupt, so that the driver can poll the board for 8 bytes per channel 1000 times per second. The polling is either slave (PIO), or busmaster (DMA). Each board generates 1000 interrupts/second, no matter the kind/number of ports on the boards. The driver knows if that's a single channel board, with 8 bytes to fetch, or quad E1, with 128*8 bytes to get on each interrupt. There are quite strict timing requirements : if one interrupt is lost, 1/1000th of sound on the line(s) is lost, which can be quite bad for things like HDLC (on T1/E1) or modem sound (no matter the kind of channel). Sharing an IRQ may introduce some latency, because the IRQ has to be handled by several drivers, and if each of them does not behave properly, frames can be late/lost. ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] PCI front mount chassis?
Looking at my /proc/interrupts: 0: 59709041 XT-PIC timer 5: 597050409 XT-PIC wcfxo 7: 597211339 XT-PIC wcfxo 10:4538876 XT-PIC eth0 11:3044608 XT-PIC aic7xxx, eth1 The voice cards generate an order of magnitude more interrupts than anything else. This may be why it's not recommended to share interrupts on voice cards. Don't know if the T1 cards have a similar issue. I would hope not. The x100p's are a pretty simplistic device. They probably generate an interrupt for every byte. The x100p's are also used for timing in things like MOH and MM conferences AFAIK. It seems like it would be nice to only put one card in timer mode if that is indeed what is generating all those interrupts. Could someone in the know enlighten us? The x100p incurres roughly 1000 interrupts per second. Someone on the list published a short unix command-line that essentially ran the above twice and calculated the interrupts / sec nicely. It was kind of a handy way to visually inspect the numbers to diagnose problems/issues. If I recall, that was around early/mid 2003 in the archives. I believe that is the zap timing referred to frequently relative to do you have a zap card installed. Anyway, balancing the processing required per card verses how many cards can share an interrupt is a system engineering task (regardless of what the cards are doing). However, that engineering task is complicated by the lack of published _actual_ requirements/expectations for each type of card that can be installed/supported, and therefore raises questions (and some spontaneous off-the-wall responses) that aren't necessarily based on facts. Rich ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] PCI front mount chassis?
Steven Critchfield wrote: On Fri, 2004-03-12 at 05:26, Rich Adamson wrote: I too am running 6 cards in my system, although not in a high traffic capacity load environment. So far my (limited) high-load simulations have shown no problems. So - is it apocryphal that the Digium cards (drivers) won't share interrupts? If there is a real issue with sharing interrupts then it seems to me to be a bug that needs fixing. PCI bus supports shared interrupts, why doesn't the hardware/driver? In most cases, sharing an interrupt is not a problem at all. There have been a few cases where _some_ issue was resolved by moving cards around, however the majority of those seem to be: a) abrupt system changes with no effort to seriously identify the root-cause, b) newbie installations where the condition of the underlying system infrastructure is totally unknown, or, c) wild recommendations that might have had some basis a long time ago but no longer apply. What I was referring to in this case about sharing an IRQ was the actual wire trace in the PCI bus. As I understand the PCI spec, there are 4 interrupt lines called A,B,C, and D. In slot 1, They appear in that order. In slot 2 they shift, in slot 3 they shift and again in slot 4. By the time you get to slot 5, all interrupts have been in each of the 4 spots and now they have the choice of staying in the same as slot 4 or shifting again. Most cards use interrupt line A as if they are in slot 1, and therefore if you move them from one slot to another, they would most likely get their own access to the interrupt line. This is part of the reason why moving a card around in the chassis helps. This is also why I would be cautious of trying to run more than 4 high interrupt cards on the PCI bus. My next point would be that of, if you need more than 4 cards, you need more than 1 computer controlling it. That is way too many eggs for one basket. Most of the 3.3V Boards have more then 1 pci bus. The boards that i use have 3 PCU Busses - 3xXPCI, 3xPCI66, Internal with Adaptec, ide and E1000 on board ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
[Asterisk-Users] PCI front mount chassis?
I am looking for a good case to house my Digium PCI cards, I was hoping to mount them in the front for cleaner access then in the back. Unfortunately I haven't found much, does anyone have a good recommendation for chassis to use up to six digium cards? Thanks! _ FREE pop-up blocking with the new MSN Toolbar get it now! http://clk.atdmt.com/AVE/go/onm00200415ave/direct/01/ ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] PCI front mount chassis?
I am looking for a good case to house my Digium PCI cards, I was hoping to mount them in the front for cleaner access then in the back. Unfortunately I haven't found much, does anyone have a good recommendation for chassis to use up to six digium cards? Probably not cost effective, but i had looked into a few 6U CompactPCI chassis...stick a CPCI to PCI adapter card in there. *rummagerummage* Ah-hah. http://www.pcisystems.com/PCI-ADAPTER.html Something like that. Except that particular one wouldn't work for some cards because it is PCI 2.1, not 2.2. ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] PCI front mount chassis?
On Thu, 2004-03-11 at 23:03, Jeff Stohl wrote: I am looking for a good case to house my Digium PCI cards, I was hoping to mount them in the front for cleaner access then in the back. Unfortunately I haven't found much, does anyone have a good recommendation for chassis to use up to six digium cards? What makes you think you could reliably run 6 cards at once? The PCI bus only has 4 interrupt lines. Anything over that is shared. -- Steven Critchfield [EMAIL PROTECTED] ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] PCI front mount chassis?
I am running six reliably right now. Surely I am not the only one doing a large capacity single site? From: Steven Critchfield [EMAIL PROTECTED] Reply-To: [EMAIL PROTECTED] To: [EMAIL PROTECTED] Subject: Re: [Asterisk-Users] PCI front mount chassis? Date: Fri, 12 Mar 2004 00:35:40 -0600 On Thu, 2004-03-11 at 23:03, Jeff Stohl wrote: I am looking for a good case to house my Digium PCI cards, I was hoping to mount them in the front for cleaner access then in the back. Unfortunately I haven't found much, does anyone have a good recommendation for chassis to use up to six digium cards? What makes you think you could reliably run 6 cards at once? The PCI bus only has 4 interrupt lines. Anything over that is shared. -- Steven Critchfield [EMAIL PROTECTED] ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users _ Fast. Reliable. Get MSN 9 Dial-up - 3 months for the price of 1! (Limited-time Offer) http://click.atdmt.com/AVE/go/onm00200361ave/direct/01/ ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] PCI front mount chassis?
Jeff Stohl wrote: I am running six reliably right now. Surely I am not the only one doing a large capacity single site? I too am running 6 cards in my system, although not in a high traffic capacity load environment. So far my (limited) high-load simulations have shown no problems. B. ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] PCI front mount chassis?
On Fri, Mar 12, 2004 at 06:48:41AM +, Jeff Stohl wrote: I am running six reliably right now. Surely I am not the only one doing a large capacity single site? You mean 6 quad span boards ?? In the T1 world, it's 576 channels on a single PC, 720 if E1. What kind of configuration can handle that load reliably ? What's the application ? -- Nicolas Bougues Axialys Interactive ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
