How to enable ethernet port for output on Airport Express...

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Level 2

200 points

How to enable ethernet port for output on Airport Express...

Hi... I currently have an Airport Extreme (802.11n) configured to allow its network to be extended... Then I have one Airport Express (new in the past year) that is set up elsewhere in my house as the network extender...

I now want to add a second Airport Express to this same network and place it in my garage... I want to be able to use its single ethernet port to connect a single wired security camera to my network..

Is that doable??? And if so, what do I need to do to set that up, settings wise???

thanks... bob..

Two 17 inch MacBook Pros and a 32G WiFi+3G iPad, Mac OS X (10.6.6)

Posted on Feb 3, 2011 12:59 PM

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Answer 1

Best reply

Bob Timmons

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Level 10

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Feb 3, 2011 1:04 PM in response to Robert Paris

Hopefully, there will be a strong wireless signal in the garage.

Setup the garage Express to "extend" as well. The ethernet port is automatically enabled when you do this.

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Answer 2

Robert Paris Author

Level 2

200 points

Feb 3, 2011 2:36 PM in response to Bob Timmons

Hi... Thanks for the answer... I did take my existing Airport Express, unplugged it and walked it out to the garage... I plugged it back in where a 2nd one would live... It connected to my Airport Extreme with about 5dB less signal than the signal that one normally has in its normal (in the house) postion... And the signal level was still a good 30 dB above the noise floor so hopefully that will be sufficient... My punt position would be to run an ethernet cable from the garage to my base station but that would be a pain...

For grins, since I've not done it before, I think tonight I will take another wired camera I have and plug it in to my existing airport extreme to verify that I can connect to it...

I appreciate the response...

thanks... bob...

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Answer 3

Feb 3, 2011 4:10 PM in response to Robert Paris

If you are interested, we can provide you with a nice method to evaluate the Signal to Noise ratio (SNR) at the location where the Express is residing. Post back if you are up for some simple negative number math.

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Answer 4

Robert Paris Author

Level 2

200 points

Feb 3, 2011 7:06 PM in response to Bob Timmons

Sure... Share the math... I'm an Electronics Engineer so I like the math...

And just to try to understand the Express a bit better, I pulled out the manual tonight and I can't find where it even talks about "extending" the existing network... I even did a search through the manual on the word "extend" and found it only in one place as follows...

"...You can also connect your AirPort Express to an existing AirPort Express or AirPort Extreme wireless network to extend the range of your network using WDS."

And I don't use WDS, at least that's not how I'm set up... Of the 4 choices for creating or joining a network on my existing Express,

Create a wireless network
Participate in a WDS network
Join a wireless network
Extend a wireless network

I clearly use the last one and always have since I first set up this first Express unit... But where is that talked about in the documentation??? Obvioulsy I figured it out somehow but I am certainly not seeing that in the setup guide...

Where is that info??? And it is in that mode, correct me if I am wrong, where you are telling me the Ethernet port will automatically going to come to life and be available to connect my wired camera to my network??? Right???

I am going to go test it shortly with an older wired camera I currently have hooked up to my base station...

Holler back... thanks... bob...

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Answer 5

Feb 3, 2011 7:29 PM in response to Robert Paris

The setup guide is there to get a very simple, basic network up and running for the average user. Check the main forum page for documents like Apple AirPort Networks, about 70 pages of documentation there.

If you have your Mac laptop handy and you want to find a good location for an "extending" device, this will help. Remember, the device can only extend the bandwidth that it receives. It does not "boost" the signal. It can only take what it receives and make it go further.

The most useful measure for wireless is Signal to Noise Ratio, or SNR. You get this by finding the Signal (expressed in dB) and subtracting the Noise (also in dB) to get the SNR.

Take your Mac laptop to a location where you have an "extending" AirPort device. Power down the extending device temporarily. On your laptop, open AirPort Utility and click Manual Setup. Click directly on Wireless Clients.

Example...Signal -70 dB - Noise (-90 dB) = 20 dB SNR

Then use the guide posted by forum expert Tesserax to evaluate your SNR at that location. You want at least 25 dB...higher is better...at the location where you place the extending device. It can only extend what it receives.

o 40dB+ SNR = Excellent signal
o 25dB to 40dB SNR = Very good signal
o 15dB to 25dB SNR = Low signal
o 10dB to 15dB SNR = Very low signal
o 5dB to 10dB SNR = No signal

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Answer 6

Robert Paris Author

Level 2

200 points

Feb 3, 2011 9:23 PM in response to Bob Timmons

OK, so I took my existing Airport Extreme out to the garage, plugged it in and then connected one of my old, wired network cameras to the ethernet port... It worked... good deal... The downside is that the signal is only 20 dB above the noise floor...

Is there any way, short of bringing the base station and extreme unit closer together, to increase signal levels??? Any sort of signal booster at the base station (source) end???

thanks... bob..

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Answer 7

Feb 3, 2011 10:16 PM in response to Robert Paris

The bottom line here may be that it worked. Maybe not quite the desired signal, but a usable signal. Your routers are probably already at 100% Transmit Power, so other than moving devices closer together or somehow minimizing the obstructions that the signal must pass through, there's really not much more that can be done using wireless.

If the garage is on the same master electrical circuit, a pair of ethernet powerline adapters can provide a pseudo ethernet signal that could be used to feed an AirPort to provide a stronger wireless signal since it would be "creating" a network, not extending it. Running an ethernet cable is the "best" option for performance, but probably the least attractive in terms of installation.

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Answer 8

Robert Paris Author

Level 2

200 points

Feb 3, 2011 10:26 PM in response to Bob Timmons

Yes... I'm at 100% Transmit power as you suspected... I will go forward with my install and if the connection is unreliable, I will consider pulling an ethernet cable from the base station out to the garage...

I appreciate the help... thanks... bob...

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