[AG-TECH] Single vs multiple machine node?

John I. Quebedeaux, Jr johnq at lsu.edu
Tue Mar 25 18:04:00 CDT 2008

For room nodes, I prefer to have 3 machines involved still:

1 machine: presenter. I run the AG client and VPCScreenProducerService to
stream that "screen" - but also this is where I can run the client to pickup
data files, etc. from the client and share them (or VNC, etc.)

2 machine: Display with Audio and one Video Capture (quad is fine, but I
typically would default this machine to one stream - add the others if
needed?). This is effectively the operator's machine, he rarely has to touch
the next one - also, I don't always need all the video streams. Runs an AG

3 machine: Capture is my backup audio/headphones for monitoring, quad
capture video card (even if i use just 3). Runs just a service manager.

The Display node is the one that needs the better video card (my experience
is the RAM on the card makes the most difference for video - at least 256Mb
on the card). The capture machines need adequate bus (PCI, etc.) bandwidth
for all the video the bus I would think.

Display I don't like to bog it down with all the VICs. I just run one Video
Service for the single capture and consumer (less confusing for the
operator). I like the redundancy in equipment as well.

Capture allows me to monitor the entire meeting's audio via a separate RAT
with headset as long as I don't open the mic on a headset in the same room,
I'm good. This really lets me make sure our audio is balanced with everyone
else's. Also perfect for testing echo ahead of time.

The only confusion for the operator is if he's having to switch to the
capture machine (KVM) and forgets which machine he's looking at! So, like
previous comments I like to run the main room's RAT on the display node. I
can also let the internal room see (if I want to show them) their audio
status, which isn't a bad idea.

For this setup - I can handle small and large meetings just fine. I do
believe in incorporating the presentation component - more and more folks
just bring their pen drives these days I'm finding....  And lately I can
simply stream (watch that desktop resolution though and have decent machine
for this) the desktop now within VIC.

-John Q.
John I. Quebedeaux, Jr.; Louisiana State University
Computer Manager LBRN; 131 Life Sciences Bldg.
e-mail: johnq at lsu.edu; web: http://lbrn.lsu.edu
phone: 225-578-0062 / fax: 225-578-2597

> From: Dioselin Gonzalez <dioselin at gmail.com>
> Date: Mon, 24 Mar 2008 15:49:33 -0500
> To: <ag-tech at mcs.anl.gov>
> Subject: [AG-TECH] Single vs multiple machine node?
> Hello (and greetings to all the people with whom I have worked in the past!!),
> In building our nodes I wanted to ask the community your
> thoughts/suggestions/experiences on having a single machine node.  We
> wonder if having a quad-core machine (instead of 3 separate audio,
> video and display ones) will be enough for sessions with many
> attendees, streaming MPEG4 and running shared applications.  Jason
> Bell reported CPU usage of 40% with 4 video streams
> (http://www-unix.mcs.anl.gov/web-mail-archive/lists/ag-tech/2008/03/msg00045.h
> tml);
> we are planning to send up to 8 video streams.
> I'd appreciate your recommendations.  Thanks much!
> Dio.-
> -- 
> Dioselin Gonzalez (SL: Chica Digital)
> Research scientist
> Louisiana Immersive Technologies Enterprise
> http://virtual-dio.com/
> http://www.lite3d.com

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