[Asterisk-Users] Asterisk on PowerPC v. Intel/AMD

[Benjamin on Asterisk Mailing Lists]

> I was wondering if anyone has any side-by-side comparisons of capacity on
> Mac hardware vs. Intel/AMD hardware, doesn't have to be anything official,
> just some people with real-world asterisk on PPC experience.

I have run a bunch of SIP streams straight through (reinvite=no) a
PIII 500MHz based IBM on to a 604 (pre-G3) 120 MHz PowerMac 9500
further on to a third, bigger box hosting a conference to accummulate
all the calls. I wanted to see which machine would max out first, but
I couldn't saturate them. However, the PIII's loadavg was going up
much steeper than that of the Mac. The IBM even had twice the memory
(256 MB vs 128 MB).

I have run ten ILBC to G711 transcoding calls over IAX on my Powerbook
G4 while executing heavy Photoshop filters and moving the Photoshop
editing window over the screen like a madman without any artifacts on
the sound of the calls. I have even repeated the whole experiment
running MacOSX inside MoL under Yellow Dog Linux with two instances of
Asterisk, one under YDL another under OSX -- Still no sound artifacts.

The only thing that creates sound artifacts is starting/quitting
X-lite. Nothing else will. Also, when you run X-Lite on  the Powerbook
and let it connect to Asterisk also running on the same machine, then
call the demo, it won't be able to properly play back the recording
coming from Asterisk. X-Lite is probably the worst resource hog I have
ever seen. I think that running a recursive Lisp function to calculate
the factorial of 100.000 on a 1980s VAXcluster wasn't as much of a
resource hog as X-lite although I can tell you that my buddy and I
almost got expelled from the curriculum when we did this.

On subjective sound quality tests any Mac based Asterisk box I have
come across sounded noticeably better than x86 based ones twice or
three times the clock rate and most of the users have confirmed this.

Nicolas Gudino in Argentina has replaced a 1.9GHz Athlon box with a
300 MHz PowerMac 9600 running five Zaptel cards and he says everything
works much better now.


> in number of Sip -> Zap concurrent conversations as well as just how many
> pure Zap channels you can have running concurrently on the Mac hardware

The trouble with that is that I haven't got the Zaptel hardware nor
the PSTN environment to test that many channels, but if you are
seriously interested in some load benchmarks, I would like to suggest
to contact TerraSoft Solutions, the sponsors of YDL, who also
sponsored the original work to get Asterisk and Zaptel to work on
LinuxPPC. They are the Mac Linux guys who sell Macs with YDL
pre-installed and they should have a vital interest to show how well
their PPC Linux boxes stack up against x86 boxes. They also have the
finest and latest Mac hardware to test on. The guy in charge there is
Kai Staats. http://www.terrasoftsolutions.com

> Is Asterisk easier to install on YellowDog or is another distro better on
> PPC Hardware?

YDL is basically Red Hat for PPC with the red hat logo replaced by a
yellow dog logo. If you are familiar with Red Hat you will feel at
home on YDL. I personally don't fancy RHL that much but as of YDL
3.0.1 Asterisk and Zaptel build out of the box and YDL is the most
common LinuxPPC distro. You won't get anybody saying "You're running
this on what?" when you ask for assistance ;-) In other words, YDL is
a pretty safe choice when all you want to do is run Asterisk.

> How much does clock speed of the PPC matter from 1.8GHz-single to
> 2.5GHz-dual in terms of capacity?

In my experience using Macs since about 1994 with BSD, clock rates
don't seem to matter a lot. Then again, I am not a graphic designer
editing 500 MB poster sized high resolution fotos or video content or
Maya or what other fancy stuff there may be. For those things you can
never get enough horsepower. But server applications do rather well on
the Mac, even something that is a little more demanding such as
telephony.

So, unless you really want to saturate one or more quad T1 cards I
believe a G5 is overkill. A refurbed G4 will probably be more than
enough for most Asterisk applications.

> Any other catches when running Asterisk on PPC?

G.729 codec is not available, at least not yet.

No on board serial ports on the desktops/towers (only USB) which may
limit your choice of UPS system if you want the UPS to be able to
shutdown your Asterisk server. You can of course put a serial port PCI
card into the box, but that wastes a precious PCI slot which you could
use for another Zaptel card. The Xserve 1U servers have serial ports
though. Pre-G3 vintage Macs also had serial ports (before USB).

rgds
benjk

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