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View Full Version : Wireless bridging Q: Will it see the server?



andy_c
2006-01-01, 10:41
Hi all,

This is my first post here. I've had an SB2 for a while now and am quite pleased with it. It's currently being used in the wireless mode. I'm a pretty hardcore audiophile, so I'd like to use it in the wired mode, as even the very rare glitches I've had are enough to give me audiophile nervosa :-).

I live in an apartment and don't have in-wall ethernet wiring, and running a cable between rooms isn't feasible. So I've decided to build a quiet PC music server and put it in my listening room. I want a wired connection from the new music server to the SB2. here's my setup.

Spare bedroom
Cable internet connection
Wireless router
Main computer (currently running SlimServer, but it will be uninstalled and running instead on the new quiet PC in the living room). Has wired connection to router

Living room (listening room)
Wireless SB2
Laptop with wireless acting as remote
New quiet music server running SlimServer will go here.

Here's what I want to do. I'd like to still be able to get internet radio in the listening room. This must be done wirelessly, since my cabled internet connection is in the spare bedroom. Also, I want to rip CDs on the machine in the spare bedroom and transfer files wirelessly from that machine to the new quiet server in my audio rack/shelf. My proposed solution is to set up the SB2 as a wireless bridge. Using a crossover cable, connect its ethernet jack to the ethernet jack on the new quiet server in the listening room. Here are two questions:

1) Will the SB2 "see" the SlimServer running on the quiet PC connected to the ethernet port of the SB2?

2) Will my laptop with wireless be able to "see" the SlimServer running on the quiet PC connected to the ethernet port of the SB2?

Thanks

Mark Lanctot
2006-01-05, 10:55
An interesting question no one's answered yet. Now I haven't actually done this so I have no practical experience with it, but I'll take a crack at it:


1) Will the SB2 "see" the SlimServer running on the quiet PC connected to the ethernet port of the SB2?

I'm trying to wrap my head around this one. It's kind of a "chicken-or-egg" question - the SlimServer is connected through the network through the very device it's acting as a server to.

However, provided the bridging function and the Squeezebox function operate independently in the SB2 (I believe they do) this should work.

To your wireless router, the SlimServer PC looks like an independent client with its own IP. The SB2 looks like another independent client with its own IP as well. When one goes looking for the other, it should be able to find it.

The only fly in the ointment here is MAC addresses. Since I will be using bridging for a second SB setup, I'm reading up on it. There are indications that both the SB and the bridged, connected PC may show the same MAC address to the router. This may confuse certain routers and break the functionality.



2) Will my laptop with wireless be able to "see" the SlimServer running on the quiet PC connected to the ethernet port of the SB2?

It should, for the same reason as above. The SlimServer PC exists as a network client on the LAN with its own IP address.

Mark Lanctot
2006-01-05, 14:40
Incidentally, I'm typing this from my laptop, which I just connected to an SB3 using a crossover cable. Completely painless, and works like a charm.

The lights on the laptop NIC immediately turned on and Windows indicated an active 100 Mbps connection but I initially had no connectivity - then I remembered to activate wireless bridging.

I couldn't get to it with the SB3 set up as-is, and I couldn't get back to the networking setup screen, so I power-cycled the SB3. I went through the wireless setup again, and just after the "Connect via wireless" page I got a new option:

"Bridge wireless to ethernet".

I enabled that, accepted my other setup entries by pressing FWD on the remote, and both the laptop and the SB3 connected perfectly.

In fact the connection seems to be faster and definitely more stable than the laptop's own wireless NIC. Obviously it doesn't matter whether the SB3 is on, playing or in standby. As long as it's receiving power it's acting as a bridge.

I haven't done any network traffic studies, but I'm curious what it will do if I attempt to saturate the connection. Will it give priority to music playback and throttle down the bridged connection? I hope it will, but as I understand it the bridging feature is quite simple and will probably attempt to pass as many packets as it receives to the connected device. So you probably could starve both devices, but I haven't tested this yet.

But this effortless operation is good news for me since I will be using a second Squeezebox in my basement where I have a PC that will require wireless network access. I wanted an SB down there, this saves me the cost of a wireless NIC.

In regards to your particular problem, now that it's working like a charm for me, I actually don't have any tools to check what MAC addresses are being passed back to the router. :-) My router is showing 1 connected wireless device having the MAC address of the SB3, as it did before. It does not show all associated MAC addresses, just wireless ones, but the static IP assignments I used for the SB3 and my laptop remain and work fine, including file sharing and SlimServer web page access over the network.

In your case I believe wireless bandwidth starvation might become an issue. Your SlimServer will have to stream data to your router through your SB, then back to your SB. They cannot stream data directly between each other, it will have to be through the router. Now, one direction is upload and the other is download, but still, that's a lot of wireless traffic. Since you indicate you are an audiophile, you probably have FLAC files, so automatically you will be wireless-bandwidth-constrained.

I will do some network tests and see what speeds I can come up with and (more importantly) if I can get the SB3 to choke on FLAC playback with heavy bridge traffic.

Mark Lanctot
2006-01-05, 16:19
Interesting!

I ran some tests using RacoonWorks SpeedTest (http://www.raccoonworks.com/Products.htm#SpeedTest) and here are my conclusions:

1. Wireless networking speed is a tad slower than with my laptop wireless NIC, but it's more stable for web browsing and general usage as my wireless NIC's connection often goes from "Excellent" to "Fair". My wireless NIC speed is about 15.25 Mbps, the SB3 was about 13.5 Mbps.

2. Even with a fully saturated bridged connection and SB3 FLAC playback, SB3 operation does not interfere much with bridged traffic. Obviously there is some slowdown, but the bridged connection's speed is still quite acceptable and the SB3 does not suffer audio dropouts. The only noticeable effect in SB3 operation is a ~5-second pause as the buffer fills, which is a little longer than normal. Bridged wireless speed dropped to 11 Mbps.

3. I suspect there will be no impact on the bridged network traffic when the buffer isn't filling since the SB3 is acting like it would be in standby. However I forgot to perform this test, but I made a few mistakes (not reported below) where I mistimed the buffer filling so that only a part of it took place during the file transfer and I noticed increased file transfer average speed.

Details of test: the bridged device downloads a 14 MB MP3. This is compressed data, as recommended when doing this testing, and it takes ~30 seconds to download so the connection has a chance to stabilize at a certain speed.

The SB3 is either in standby or playing a FLAC file. When playing a FLAC file, I skipped to another track after the bridged file transfer started in order to cause the SB3 to fill its buffer to 100% while the bridged traffic saturated the connection.

The notebook uses a very common Intel PRO/Wireless 2200BG wireless NIC that was included with many Intel Centrino platforms.

Attached are the results in graphical format. The first one compares the SB3 bridged wireless speed (first 3 bars) versus the laptop wireless NIC's speed (last 3 bars). The second one compares the same SB3 bridged wireless speed with the speed obtained when the SB3 was filling its buffer with a FLAC file.

Note that I am in a wireless hellhole. I am less than 1 km away from a 500 KW FM transmitting tower. It's so strong I can pick it up on my subwoofer and my wired phone. I also have 7-12 other wireless networks in detection range. So almost everyone's results will be better than mine.

In conclusion, the wireless bridging function is quite capable and you will only experience issues when your SlimServer is passing data to the SB buffer, and even then it will only be for a few seconds.

andy_c
2006-01-07, 13:13
Mark,

Wow, I had pretty much given up on this - then I was just browsing the forum and saw your thorough, detailed posts. Thank you very much!

Now, regarding this issue:


Your SlimServer will have to stream data to your router through your SB, then back to your SB. They cannot stream data directly between each other, it will have to be through the router.

I'm trying to be able to stream data to the Squeezebox without using any kind of wireless connection at all - except for internet radio. This would be for minimizing the possibility of dropouts or glitches. But it looks like that can't happen with the configuration I had proposed in my original post.

So how about this idea? Suppose I got, say, a USB wireless adapter for the server. Then file transfers between the server in the living room and my main computer in the spare bedroom would go through the wireless USB adapter. How about if I enabled internet connection sharing (ICS) on the server and connected its ethernet port (from the built-in NIC on the mobo) to the ethernet port on the Squeezebox. Then the Squeezebox would be configured for a plain old wired connection, with no wireless or bridging or anything like that. Does this sound like it would work?

ceejay
2006-01-07, 14:18
Another alternative you might want to consider is "home-plug" ethernet - using your mains to carry IP from one room to another. Put one in one room, another in the other room, and off you go. This sort of thing - http://www.homeplugs.co.uk/acatalog/HomePlugs.html (NB I don't have any myself, as wireless works well for me, but I can see the attraction)

JAT.

Ceejay

Mark Lanctot
2006-01-07, 14:47
Mark,

Wow, I had pretty much given up on this - then I was just browsing the forum and saw your thorough, detailed posts. Thank you very much!


You're welcome, I just hope it will work for you. I think it will.



Now, regarding this issue:

I'm trying to be able to stream data to the Squeezebox without using any kind of wireless connection at all - except for internet radio. This would be for minimizing the possibility of dropouts or glitches. But it looks like that can't happen with the configuration I had proposed in my original post.

So how about this idea? Suppose I got, say, a USB wireless adapter for the server. Then file transfers between the server in the living room and my main computer in the spare bedroom would go through the wireless USB adapter. How about if I enabled internet connection sharing (ICS) on the server and connected its ethernet port (from the built-in NIC on the mobo) to the ethernet port on the Squeezebox. Then the Squeezebox would be configured for a plain old wired connection, with no wireless or bridging or anything like that. Does this sound like it would work?

I don't know much about ICS. As I understand it, it turns the *PC* into a bridge, either wired or wireless. The Squeezebox and the server would not necessarily see each other in this mode. I could be wrong, but ICS is just that - Internet Connection Sharing - it shares the Internet connection to devices downstream, but does not allow traffic between a downstream PC and the ICS PC. The ICS PC is not acting as a proper router, it doesn't know what IP address is where, nor can it direct LAN packets to their appropriate destination, only WAN (Internet) packets.

The wireless connection is not bad at all! There are no glitches, playback is perfect. There can be dropouts if the buffer underruns though, but the buffer is really quite large - you ought to try it with an MP3 some time, it really takes a long time to empty.

There are various tests you can do to see if you have the required bandwidth. For example, try the Network Test Plugin: http://forums.slimdevices.com/showthread.php?t=18149 If you can achieve 1500 kbps (2000 kbps preferred) at 100% you will never experience a dropout with FLAC.

As I said in my post, I am in a very poor wireless networking situation. Yours is almost surely better than mine. I have never experienced a dropout caused by wireless bandwidth starvation.

The drawbacks of your apartment situation is the presence of other wireless networks. But the advantages are less distance and no floor/ceiling to go through. I am going through 2 walls, 1 floor and 30-40 feet of air.