Need help with Airport Extreme and mixed g/n network

1. Yes, the wireless network will only be as fast as its slowest connected client
2. See #1
3. That depends on your expectations.
4. If you find file transfers from machine to machine slow or machine to the USB HDD, then yes you should care.
5. To separate them out, you should connect the routers with ethernet and disable DHCP on one of them (for example, your linksys), such that only one device is distributing IP addresses. You can also change the settings of your AEBS to only 5ghz (n-only) so that g devices couldn't even connect.

Hope that helps some.

I have a Linksys WRT54G and a new Airport Extreme n.

For wireless clients I have a 17" powerbook that supports b/g and a Macbook pro that supports abgn

What I have done is set up two SSIDs. The first one is G only with the linksys. The second one is set to a/n only using 5GHz. Both of the APs are connected together. Currently the linksys is acting as the router. I may switch to the airport extreme (which is currently in bridging only mode) once I validate the stability of the airport extreme. I don't want my router rebooting too often since I use vonage.

What my solution does is allows my two laptops to both maximize their wireless rate since I basically have an AP dedicated for each one. I may get a cardbus N card for the powerbook and an expresscard N adapter for the macbook pro (though I see that it is possible, albiet not supported, to upgrade the MBP Core Duo to abgn).

b/g uses only 2.4 GHz. a only uses 5 GHz. n can use 2.4 or 5.

If you do run something like I do, use two different SSIDs if you want to guarentee you know which AP you are connecting to..

Also, install kismac (google it) and check to see what other APs are in your area. If you are using 2.4 GHz, the only channels you want to use are 1,6, or 11. All other channels overlap with those three and can cause interference. You want to make sure that you pick one of those channels that is farthest away from all the other aps in your neighborhood. I live in Seattle and can see about 10 APs in my living room.

good luck!

Let me break it down a bit...

Carpediem68 said:

Hi gang,

I don't pretend to really understand all of this but let me describe my situation. I have 3 computers at home:

1. my wife's PC cabled in my new airport extreme "pre-n" base station
2. my MacBook Pro 17" (1 month old) with an internal "n" wireless capability
3. my daughters 1.83 ghz iMac with built in "g" wireless capability
4. I also have an airport express plugged into my stereo to run iTunes which I assume is "g"

Click to expand...

So you have a mix of devices that can use G and N. You also have a mix of wired and wireless devices.

For wireless, you have two hosts (devices, computers, etc) your Macbook and your daughters iMac.

What I am not sure about is how your Airport Express connects to your router. Do you have a wired ethernet that goes from your airport express to your airport extreme or are you connecting the two airports together with WDS over wireless?

If they are connected via wireless and cannot be connected via wired, then you need to keep your airport extreme running in a mode that is compatible with G. That means 2.4 GHz.

If they are connected via a wired ethernet, you can dedicated the airport express to provide wireless connectivity for your daughters imac. I would set the Network name of the airport express to something different from the airport extreme. I would then set up her imac to connect to that network.

Then I would set up the airport extreme to be in A/N or N only mode in the 5 GHz band. You would then set up your macbook pro to connect to that SSID. You know have one access point per wireless client. You are maximizing your wireless network throughput (assuming you are not subject to interference.. see below.

Carpediem68 said:

Plugged into my airport extreme is a printer (via cat5) with networking ability, an xbox 360 (cat 5), my wife's pc (cat 5) and a western digital hard drive (via usb)

Click to expand...

This means that your xbox and your wife's pc are not limited by your network at all..

The HD is interesting and I will address that below. I have 3 HDs connected to my Airport extreme.

Carpediem68 said:

My questions revolve around the fact that I have this mixed network.

Question 1 - Does the "g" iMac slow down my airport extreme router?

I'm pretty sure the answer is yes. I really wish the apple store people would have told me this when I bought it 2 weeks ago. The machine is for my daughter in 5th grade and perfectly fine for her needs. I had no idea it would actually drag my laptop speed down or I would have upgraded. Ugg.

Question 2 - Does the Airport express on my stereo slow down my airport extreme router?

Click to expand...

When you stream music to your airport express, you are using up whatever bit rate the music is ripped at.. somewhere between 128 and 160 kbps.

802.11g has a real world max rate of around 20-25 Mbps. So the rate is negligible.

Carpediem68 said:

I have no clue here.

Question 3 - Is the slow down a big deal?

I can't figure out how to measure the speed of my network. I'm sure there is a software tool or widget or something but I have no clue what it is. I read on some net articles that it is a huge deal .. in others I read that it only matters when both the iMac and the Macbook Pro are hitting it at the same time. Again .. remember .. I'm clueless.

Click to expand...

Let's think of where you are rate limited... When you are surfing the internet, the bottleneck is likely your connection to the Internet. The top speed of cable or dsl is probably around 7 or so Mbps. That is way under what you can expect from G. Even if all your devices were connecting with G, that means that I would expect around 10 Mbps for your wireless devices. Pretty good.

If you really want to test your network performance with a hard core test.. Not for the feint of heart.. you want to use something like iperf.

http://dast.nlanr.net/Projects/Iperf/

It is run via the command line. It is really beyond the scope of this to just explain how it works and how to use it..

super basic you install it on two machines you want to test the network between and on one you run via command line

iperf -s
to start up an iperf server

on the other you run
iperf -c <ip address of server>

and it runs.

Carpediem68 said:

Question 4 - Should I care?

Everything works now .. should I even worry about this?

Question 5 - If I should fix it, how do I run multiple routers?

I still have an extra linksys "g" router. I know there is a way to somehow add it to my network and assign the iMac (and possibly airport express) to it and then ramp up the airport extreme for my Macbook Pro. I am, however, clueless as to how to accomplish this. Can anyone show mercy on me or at least point the way to a guide?

Cheers,
David

Click to expand...

I don't think you can make the airport express a wireless client of the linksys. This sounds to me then that the express cannot be wired to the extreme. In this case you need to use the airport extreme in a 802.11g compatible mode and set up WDS.

You certainly could connect the linksys up and dedicate it to your daughters connection. You would then have your macbook and the airport express as the two wireless clients to your airport extreme. Not horrible, since the airport express is not using up a bunch of bandwidth. What I am not sure of is how much benefit you will get out of using your macbook in N mode over just using it in G mode.

The thing that would most benefit from faster network perfomance will be your airdisk access. I have found that it is fast enough for what it provides me... I am pretty sure that I will be able to use it for time machine in OSX 10.5. And that is what matters most.. I wish it supported hardware raid boxes, but I have seen mixed reviews in regards to that.. mainly to have the backup/time machine drive in mirrored mode, to backup the backup.

On a side note, I have bought two hard drive enclosures this week, both are eSATA/USB2 boxes. I plan on picking up an eSATA expresscard for my macbook and use that for high speed transfers when I need them.

Lots of stuff, be specific on what you want explained further.

Carpediem68 said:

King, Thanks for the reply. With respect to bringing the Linksys back into the system could you be a bit more specific? Remember .. I'm clueless .. wink.

Click to expand...

connect the linksys to a wired port on the airport extreme

Carpediem68 said:

So I have my cable modem cat 5 go into my APX and from that I have another cat 5 go into my linksys "g" router. Right?

Click to expand...

if APX means eXtreme and not eXpress, yes.

cable modem -> Extreme wan port
linksys -> extreme LAN port

Carpediem68 said:

How do I turn off DHCP in the linksys?

Click to expand...

http://linksys.custhelp.com/cgi-bin/linksys.cfg/php/enduser/std_adp.php?p_faqid=3733

Carpediem68 said:

Will the iMac need to be reconfigured in terms of security? How will it (and the airport express) know to look at the linksys and not the APX?

All help is appreciated

Click to expand...

Change the network names so that they are different. Specifically, the linksys would have one SSID (wireless network name) and the two airports connected together via WDS would share a different SSID.

Setting Linksys SSID:
http://linksys.custhelp.com/cgi-bin...p.php?p_faqid=3967&p_sid=fQrvDtvi&p_lva=3686#