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Christopher Farley
2004-01-20, 22:28
Does anybody have any experience doing raw PCM streams over WiFi?
The Squeezebox spec sheet recommends 'switched wired ethernet' for raw
PCM. But 802.11b/g's 11 Mbps is more than enough for streaming
uncompressed audio streams.

I was planning to start digging into my walls to run cat 5 cable, but
so far I've been having very good luck doing PCM through the air. The
buffer stays nice and full (I've seen it spike down to 60-70% once, but
it generally stays 95-100% full).

I have not been doing this for very long (3 days), but so far it seems
reliable for me. I live in an old house, and have a dedicated
slimserver/cd ripper in the basement. This server is connected to a
D-Link DWL-900+ access point in "wireless client" mode via crossover
cable. (It's a bit overkill price-wise, but I have a spare...) The
server is a low-power consumption VIA EPIA M with a 933 MHz C3 CPU
running Gentoo Linux.

The Squeezebox is on the ground level. It's sitting in an AV cabinet
above a DVD player. I was worried that this would inhibit the wireless
signal, but it seems to be doing just fine.

I have a small wired network upstairs, with another DWL-900+ access
point (in "access point" mode) on that network. On my upstairs Linux
workstation, I can actually use xmms to play FLAC files off of the
basement computer's music drive (shared by NFS) *while simultaneously
playing raw PCM streams on the Squeezebox!* All of this over wireless,
and all without dropouts. This is in an old 1920's house with lathe and
plaster ceilings and walls. I've also microwaved up a burrito without any
catostrophic effects. Oh yeah, and I'm also doing 128-bit WEP encryption
(even though it's near worthless).

Anybody else doing uncompressed streams over WiFi? Is this inherently
unreliable? Am I asking for trouble?

One other question... I don't know all that much about wireless. The
wireless server and the Squeezebox are both "clients" of the upstairs
access point. Does this mean that the AP relays (repeats) the signal
from the server and re-broadcasts it to the Squeezebox (as an ethernet
switch would)? Or do the wireless server and Squeezebox communicate with
each other directly? If my server is broadcasting a stream of bits,
surely it seems most efficient for the Squeezebox to listen to its
broadcast directly

I'm just curious, because if the server is broadcasting a signal up
three floors to the AP, and the AP is relaying it back to the
Squeezebox, it seems crazy. I can't imagine that it works that way...

--
Christopher Farley
www.northernbrewer.com

Mark A. Aiken
2004-01-21, 00:38
So your question is that your wireless setup is working fine, and you're
wondering if this is a figment of your imagination? ;-)

Maybe you should wait to actually experience a problem before ripping
open your walls to run Cat5. ;-)

Mark

----- Original Message -----
From: "Christopher Farley" <chris (AT) northernbrewer (DOT) com>
To: <discuss (AT) lists (DOT) slimdevices.com>
Sent: Tuesday, January 20, 2004 9:28 PM
Subject: [slim] PCM over Wireless


> Does anybody have any experience doing raw PCM streams over WiFi?
> The Squeezebox spec sheet recommends 'switched wired ethernet' for raw
> PCM. But 802.11b/g's 11 Mbps is more than enough for streaming
> uncompressed audio streams.
>
> I was planning to start digging into my walls to run cat 5 cable, but
> so far I've been having very good luck doing PCM through the air. The
> buffer stays nice and full (I've seen it spike down to 60-70% once, but
> it generally stays 95-100% full).
>
> I have not been doing this for very long (3 days), but so far it seems
> reliable for me. I live in an old house, and have a dedicated
> slimserver/cd ripper in the basement. This server is connected to a
> D-Link DWL-900+ access point in "wireless client" mode via crossover
> cable. (It's a bit overkill price-wise, but I have a spare...) The
> server is a low-power consumption VIA EPIA M with a 933 MHz C3 CPU
> running Gentoo Linux.
>
> The Squeezebox is on the ground level. It's sitting in an AV cabinet
> above a DVD player. I was worried that this would inhibit the wireless
> signal, but it seems to be doing just fine.
>
> I have a small wired network upstairs, with another DWL-900+ access
> point (in "access point" mode) on that network. On my upstairs Linux
> workstation, I can actually use xmms to play FLAC files off of the
> basement computer's music drive (shared by NFS) *while simultaneously
> playing raw PCM streams on the Squeezebox!* All of this over wireless,
> and all without dropouts. This is in an old 1920's house with lathe and
> plaster ceilings and walls. I've also microwaved up a burrito without any
> catostrophic effects. Oh yeah, and I'm also doing 128-bit WEP encryption
> (even though it's near worthless).
>
> Anybody else doing uncompressed streams over WiFi? Is this inherently
> unreliable? Am I asking for trouble?
>
> One other question... I don't know all that much about wireless. The
> wireless server and the Squeezebox are both "clients" of the upstairs
> access point. Does this mean that the AP relays (repeats) the signal
> from the server and re-broadcasts it to the Squeezebox (as an ethernet
> switch would)? Or do the wireless server and Squeezebox communicate with
> each other directly? If my server is broadcasting a stream of bits,
> surely it seems most efficient for the Squeezebox to listen to its
> broadcast directly
>
> I'm just curious, because if the server is broadcasting a signal up
> three floors to the AP, and the AP is relaying it back to the
> Squeezebox, it seems crazy. I can't imagine that it works that way...
>
> --
> Christopher Farley
> www.northernbrewer.com
>

Caleb Epstein
2004-01-21, 07:22
On Tue, Jan 20, 2004 at 11:28:49PM -0600, Christopher Farley wrote:

> Does anybody have any experience doing raw PCM streams over WiFi?
> The Squeezebox spec sheet recommends 'switched wired ethernet' for raw
> PCM. But 802.11b/g's 11 Mbps is more than enough for streaming
> uncompressed audio streams.

Steaming FLAC and SHN files to my Squeezebox works great for
me over WiFi.

--
Caleb Epstein | bklyn . org | character density, n.:
cae at | Brooklyn Dust | The number of very weird people in
bklyn dot org | Bunny Mfg. | the office.

Christopher Farley
2004-01-21, 07:42
Mark A. Aiken (mark_aiken (AT) hotmail (DOT) com) wrote:

> So your question is that your wireless setup is working fine, and you're
> wondering if this is a figment of your imagination? ;-)

Given the Slimdevices recommendation for wired ethernet, I am a little
concerned about the robustness of the wireless solution. My goal is
ultra-reliability (zero dropouts), which is kind of why I've gone with
a dedicated server, etc.

I'm also curious why Slimdevices recommends switched wired ethernet. Is
this just an ultra cautious recommendation?

--
Christopher Farley
www.northernbrewer.com