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Anyone care to help me spec a machine that I can rack mount & install
Trixbox/Asterisk upon?

Would prefer solid state memory over HD drive.....

Also need up to 12 channels of ISDN2e/BRI. Long story short, BT want
over £3k to install a PRI.

So, here's the shopping list:

Rackmount Case
Motherboard
IDE/SD card (is it SD I'm after?)
Processor
ISDN2e Line Cards (2 x 4 port?)
RAM

Thanks.

Jono wrote:[color=blue]
> Anyone care to help me spec a machine that I can rack mount & install
> Trixbox/Asterisk upon?
>
> Would prefer solid state memory over HD drive.....[/color]

If you do this, you need to think very carefully about the filesystem
and the number of writes you can make before it dies.

[color=blue]
> Also need up to 12 channels of ISDN2e/BRI. Long story short, BT want
> over £3k to install a PRI.[/color]

Need to choose your ISDN cards carefully. That is going to be a whole
lot of interrupts.

I'm surprised that the price difference between the BRI cards and PRI
cards doesn't pay for the PRI installation.

Are you sure you can't get a PRI from somebody other than BT?

Tim

In article <mn.dd2e7d7b9f7f09a1.48968@blueyonder.invalid>,
Jono <nothanks@blueyonder.invalid> wrote:[color=blue]
>Anyone care to help me spec a machine that I can rack mount & install
>Trixbox/Asterisk upon?
>
>Would prefer solid state memory over HD drive.....
>
>Also need up to 12 channels of ISDN2e/BRI. Long story short, BT want
>over £3k to install a PRI.
>
>So, here's the shopping list:
>
>Rackmount Case
>Motherboard
>IDE/SD card (is it SD I'm after?)
>Processor
>ISDN2e Line Cards (2 x 4 port?)
>RAM[/color]

How many incoming lines do you actually need?

However, £3K from BT vs. the install for 6 x ISDN2e connections plus the
on-going rental on them... Are you sure it's not going to be cheaper in
the long-run to get the PRI?

With regard to server - how many extensions?

Although that's a bit of a moot point, given that you might need a
mother board with 2 PCI slots on it, so you'll struggle to get anything
under a 3GHz Pentium or 2GHz Xeon which would be more than adequate,
even with a moderate amount of transcoding going on (which you probably
won't be doing). Stick 512MB of RAM in it and you'll be fine - the later
versions of asterisk do not seem to have any memory leak issues, they
grow until they've had a max. number of calls through and stay there IME.
Eg. Top sorted by memory on a clients site:

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
26389 root -11 0 40856 13m 4548 S 0.0 5.6 23:07.04 asterisk
This is asterisk 1.2.13. Uptime is 32 days and this has a 4-port ISDN2e
interface on one side (mISDN driver) and 20 extensions in a busy sales &
admin office on the other. CPU is a 1GHz Via C7 and it has 128MB of RAM
avalable to the OS (It has 256MB in total, but 128M is a ramdisk which
the OS boots into off flash)

Basically what I'm saying is that any modern box will do you just fine,
so go with something you're familiar with if you've built/bought
"server" boxes in the past. The "usual" rules I'd suggest would be to
compile a custom kernel that matches the hardware, and turn off all the
non-used hardware on the mobo (eg. usb, sound, etc.) if you can. As for
booting off flash - you can get devices big enough these days to put a
"live" system on, I developed my own booting system which doesn't touch
the flash after it's booted, but you might just want to stick a laptop
drive in there to get you going...

Have you considered an IAX/SIP trunk to someone who could provide a
service using g729? Might work on a dedicated ADSL line if you have a
good business service to a decent ISP, and can get most of the 833Kb/sec
upload speed. (Although you'd only need a fraction of it on g729 with
an IAX trunk)

Gordon

on 27/11/2007, Gordon Henderson supposed :[color=blue]
> In article <mn.dd2e7d7b9f7f09a1.48968@blueyonder.invalid>,
> Jono <nothanks@blueyonder.invalid> wrote:[color=green]
>> Anyone care to help me spec a machine that I can rack mount & install
>> Trixbox/Asterisk upon?
>>
>> Would prefer solid state memory over HD drive.....
>>
>> Also need up to 12 channels of ISDN2e/BRI. Long story short, BT want
>> over £3k to install a PRI.
>>
>> So, here's the shopping list:
>>
>> Rackmount Case
>> Motherboard
>> IDE/SD card (is it SD I'm after?)
>> Processor
>> ISDN2e Line Cards (2 x 4 port?)
>> RAM[/color]
>
> How many incoming lines do you actually need?
>
> However, £3K from BT vs. the install for 6 x ISDN2e connections plus the
> on-going rental on them... Are you sure it's not going to be cheaper in
> the long-run to get the PRI?[/color]

Yes - there are 8 channels of ISDN2e in place already.
[color=blue]
> With regard to server - how many extensions?[/color]

25
[color=blue]
>
> Although that's a bit of a moot point, given that you might need a
> mother board with 2 PCI slots on it, so you'll struggle to get anything
> under a 3GHz Pentium or 2GHz Xeon which would be more than adequate,
> even with a moderate amount of transcoding going on (which you probably
> won't be doing). Stick 512MB of RAM in it and you'll be fine - the later
> versions of asterisk do not seem to have any memory leak issues, they
> grow until they've had a max. number of calls through and stay there IME.
> Eg. Top sorted by memory on a clients site:
>
> PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
> 26389 root -11 0 40856 13m 4548 S 0.0 5.6 23:07.04 asterisk
> This is asterisk 1.2.13. Uptime is 32 days and this has a 4-port ISDN2e
> interface on one side (mISDN driver) and 20 extensions in a busy sales &
> admin office on the other. CPU is a 1GHz Via C7 and it has 128MB of RAM
> avalable to the OS (It has 256MB in total, but 128M is a ramdisk which
> the OS boots into off flash)
>
> Basically what I'm saying is that any modern box will do you just fine,
> so go with something you're familiar with if you've built/bought
> "server" boxes in the past. The "usual" rules I'd suggest would be to
> compile a custom kernel that matches the hardware, and turn off all the
> non-used hardware on the mobo (eg. usb, sound, etc.) if you can. As for
> booting off flash - you can get devices big enough these days to put a
> "live" system on, I developed my own booting system which doesn't touch
> the flash after it's booted, but you might just want to stick a laptop
> drive in there to get you going...[/color]

Or perhaps I could converse with someone who has developed their own
booting system....
[color=blue]
>
> Have you considered an IAX/SIP trunk to someone who could provide a
> service using g729? Might work on a dedicated ADSL line if you have a
> good business service to a decent ISP, and can get most of the 833Kb/sec
> upload speed. (Although you'd only need a fraction of it on g729 with
> an IAX trunk)[/color]

Yes, although another 4 channels of ISDN2e is not out of the question -
gives me a total of 12. I can rent an ISDN2 channel for less than an
ISDN30 channel & the installation cost of another 2 pairs is much much
less than the £3k BT want for the PRI.

Tim brought next idea :[color=blue]
> Jono wrote:[color=green]
>> Anyone care to help me spec a machine that I can rack mount & install
>> Trixbox/Asterisk upon?
>>
>> Would prefer solid state memory over HD drive.....[/color]
>
> If you do this, you need to think very carefully about the filesystem and the
> number of writes you can make before it dies.[/color]

OK. Are you suggesting that a hard drive would be more appropriate?
[color=blue][color=green]
>> Also need up to 12 channels of ISDN2e/BRI. Long story short, BT want over
>> £3k to install a PRI.[/color]
>
> Need to choose your ISDN cards carefully. That is going to be a whole lot of
> interrupts.[/color]

I bow to your greater knowledge :-). That's why I've asked here....
[color=blue]
> I'm surprised that the price difference between the BRI cards and PRI cards
> doesn't pay for the PRI installation.[/color]

£3k? I hope not. Crikey!
[color=blue]
> Are you sure you can't get a PRI from somebody other than BT?[/color]

There is no cable in the area & this is the Openreach Excess
Construction Charge. They claim that they will have to deliver the PRI
on fibre as the distance from the exchange is too great for copper.

Jono wrote:[color=blue]
>
> OK. Are you suggesting that a hard drive would be more appropriate?
>[/color]

Depends. But you'd generally mount the flash disk read only, and then
run the system in a RAM disk.

Modern flash does last longer though.
[color=blue]
>
> I bow to your greater knowledge :-). That's why I've asked here....[/color]

I know stacking ISDN2 cards causes trouble, but I don't really know the
full details.

[color=blue][color=green]
>> I'm surprised that the price difference between the BRI cards and PRI
>> cards doesn't pay for the PRI installation.[/color]
>
> £3k? I hope not. Crikey![/color]

Well, not that much, but some of it.

I've also noticed that per channel rental is now about the same on PRI
as it is on BRI. I'm fairly sure it used to be cheaper for PRI.

[color=blue]
>
> There is no cable in the area & this is the Openreach Excess
> Construction Charge. They claim that they will have to deliver the PRI
> on fibre as the distance from the exchange is too great for copper.[/color]

Getting ISDN30 on fibre used to be a common trick to get BT to fibre up
a building. The you can get cheaper data circuits because the fibre is
already in the building.

I guess there must be a way to ask BT which makes them think about it.


Tim

Tim explained :[color=blue]
> Jono wrote:[color=green]
>>
>> OK. Are you suggesting that a hard drive would be more appropriate?
>>[/color]
>
> Depends. But you'd generally mount the flash disk read only, and then run
> the system in a RAM disk.
>
> Modern flash does last longer though.
>[color=green]
>>
>> I bow to your greater knowledge :-). That's why I've asked here....[/color]
>
> I know stacking ISDN2 cards causes trouble, but I don't really know the full
> details.[/color]

If you could discover the full details, I may well be giving you a call
tomorrow! Assuming you are the Tim I think you are. The need for more
than 8 channels of ISDN2e may well become a burning issue :-)
[color=blue]
>[color=green][color=darkred]
>>> I'm surprised that the price difference between the BRI cards and PRI
>>> cards doesn't pay for the PRI installation.[/color]
>>
>> £3k? I hope not. Crikey![/color]
>
> Well, not that much, but some of it.
>
> I've also noticed that per channel rental is now about the same on PRI as it
> is on BRI. I'm fairly sure it used to be cheaper for PRI.[/color]

Certainly, the install costs are cheaper for 8+ channels of PRI from
scratch (assuming no blasted excess charges apply to the PRI, of
course). The wholesale rental costs have been more for 30e per channel
for as long as I can recall; 28% more, to be precise.
[color=blue]
>[color=green]
>>
>> There is no cable in the area & this is the Openreach Excess Construction
>> Charge. They claim that they will have to deliver the PRI on fibre as the
>> distance from the exchange is too great for copper.[/color]
>
> Getting ISDN30 on fibre used to be a common trick to get BT to fibre up a
> building. The you can get cheaper data circuits because the fibre is already
> in the building.
>
> I guess there must be a way to ask BT which makes them think about it.[/color]

I hope so.

Jono wrote:[color=blue]
> Tim explained :[color=green]
>> Jono wrote:[color=darkred]
>>>
>>> OK. Are you suggesting that a hard drive would be more appropriate?
>>>[/color]
>>
>> Depends. But you'd generally mount the flash disk read only, and then
>> run the system in a RAM disk.
>>
>> Modern flash does last longer though.
>>[color=darkred]
>>>
>>> I bow to your greater knowledge :-). That's why I've asked here....[/color]
>>
>> I know stacking ISDN2 cards causes trouble, but I don't really know
>> the full details.[/color]
>
> If you could discover the full details, I may well be giving you a call
> tomorrow! Assuming you are the Tim I think you are. The need for more
> than 8 channels of ISDN2e may well become a burning issue :-)[/color]

More info here:

[url]http://www.voip-info.org/wiki/view/Asterisk+hardware+interrupts[/url]

The main point is to make sure the motherboard you choose is something
that doesn't share IRQs between PCI slots. In an ideal world you'd get
one where you can manually specify a fixed IRQ for each slot in the BIOS
but I don't think this is a very common thing any more. If you get
around the problem using a board with APIC (gives you more IRQs), do
some googling to see if anyone else is using the same board successfully
as I've heard of problems with certain APIC implementations.

cheers,
Paul.

p.s. yes Tim is the Tim you think he is ;)
--
Working Email:

paul-at-polog40-dot-co-dot-uk

In article <mn.dd7a7d7b11eb5777.48968@blueyonder.invalid>,
Jono <nothanks@blueyonder.invalid> wrote:
[color=blue]
>Or perhaps I could converse with someone who has developed their own
>booting system....[/color]

Drop me an email. And I've found some 8-port single PCI IADN2e cards too
- not cheap but under £1000 for the cards.

There are multiple-slot cards that can be daisy-chained together too
which eases the interrupt load on the host process that Tim alluded to,
but a single 8-port (ie 16 channel) card would be ideal for your needs.
All this is a 1-U rack case booting off flash too ...
[color=blue][color=green]
>> Have you considered an IAX/SIP trunk to someone who could provide a
>> service using g729? Might work on a dedicated ADSL line if you have a
>> good business service to a decent ISP, and can get most of the 833Kb/sec
>> upload speed. (Although you'd only need a fraction of it on g729 with
>> an IAX trunk)[/color]
>
>Yes, although another 4 channels of ISDN2e is not out of the question -
>gives me a total of 12. I can rent an ISDN2 channel for less than an
>ISDN30 channel & the installation cost of another 2 pairs is much much
>less than the £3k BT want for the PRI.[/color]

OK. Might be a cheaper upgrade option though - use the existing ISDN2es
for incoming and an Internet trunk for outgoing - mix & match? Depends
on how many incoming calls you're expecting though!

Gordon

In article <474c9e32$0$510$bed64819@news.gradwell.net>,
Tim <nutnews@kooky.org> wrote:[color=blue]
>Jono wrote:[color=green]
>> Anyone care to help me spec a machine that I can rack mount & install
>> Trixbox/Asterisk upon?
>>
>> Would prefer solid state memory over HD drive.....[/color]
>
>If you do this, you need to think very carefully about the filesystem
>and the number of writes you can make before it dies.[/color]

There's been a lot of talk recently in various places - especially with
the interest in laptops coming with flash drives, etc. The upshot is
that the bigger the flash device you can afford, the better, as they
then have more "space" to do write wear levelling and so on.

I'm still "wary" though, and although I do use them for a live
filesystem for voicemail storage, I use good old ext2 rather than ext3
and mount it with a few options to try to keep writes down.

Gordon