Time machine slow on extended Airport...

[Guest]

I have a Time Capsule running a main and guest network.  My Mac Pro is ethernet cable connected.  My Mac Book Pro is wireless.  Upstairs, where the TC is, I get 5GHz signal and excellent speed.  Dowstairs, I would get 2.4GHz signal, but very acceptable speeds in terms of internet and more importantly Time Machine.  Last month I added an Airport Express downstairs set up to extend the network so I could run Air Tunes to my amplifier.  Air Tunes works fine.  The extended network runs at 2.4GHz.  My internet access is a little slower, but Time Machine backups and access have slowed to an intolerable crawl.  I do not believe it is the TC because when I bring the Mac Book Pro upstairs closer to the TC and the internet both run much faster.  This makes me think it has something to do with the signal from the Airport Express extended network.  Any ideas on how to diagnose the issue and get the speed back up?  Thanks in advance.

[Guest]

First check to see if the AirPort Express is actually "extending" the signal....since it sounds as if it is not. Open AirPort Utility and click on the AirPort Express. In the area to the right, locate the AirPort ID of the AirPort Express and jot that down. Do the same for the Time Capsule. Move your Mac laptop close to the AirPort Express and make sure that you are connected to the wireless network. Hold down the option key on your Mac whlle you click on the fan shaped AirPort icon at the top of the screen. Look for the BSSID. That is the AirPort ID of the device to which your Mac is connected. If you see the AirPort ID of the Express, then it is extending....and more troubleshooting is needed to figure out why the speed is slow.  If you see the AirPort ID of the Time Capsule....that means that your Mac is connecting back to the Time Capsule....and the Express is not extending. Please post on your results.

[Guest]

It is definately connecting to the Express.  When I move upstairs it connects to the TC, first no the 2.4, then at 5GHz.

[Guest]

Thanks for checking. Remember that the Express can only "extend" the quality of signal that it receives. Power down the Express and keep your laptop close to the location where the Express resides. Log on to the wireless network again.Hold down the option key and click on the Apple icon in the upper left corner of the screenKeep holding the option key down and click on System ProfilerLook down the categories on the left and find NetworkClick on AirPort In the area to the right, locate the info with the name of your wireless network and look for Signal / Noise. They will be negative numbers. Example:  -50 dBm / -80 dBm Post on your results.

[Guest]

The Express is in an alcove and I have to pull some equipment to get to it which I can;t do just now.  However, I ran the test anyway and this is what I got: Current Network Information: Airport Express  Signal / Noise:          -48 dBm / -75 dBm  Transmit Rate:          104  MCS Index:          13 Other Local Wireless Networks: TC Guest Network  Signal / Noise:          -69 dBm / -94 dBm TC Network:  Signal / Noise:          -69 dBm / -94 dBm The numbers are higher for the signal coming off the TC then the Express even though the TC is upstairs and I am sitting about 10 feet away from the Express.  Is it possible that that because the Express is in the alcove, it is not receiving a strong enough signal from the TC?  Should I change the Express from extend the network to join the network so I can still use it for Air Tunes?

[Guest]

Leave the Express set to "extend", but move it as closer to the Time Capsule if possible to see how that works. Your wireless SNR (signal to noise) is right on the borderline as far as acceptable quality. Anything that you can do to minimize obstructions in the signal path between the Time Capsule and Express will help. If you can't move the Express closer, then you may have to set it to "join". It will work with a much weaker signal when it only joins and does have to extend.

[Guest]

I can't move it without defeating the entire purpose of having it which was to use Air Tunes.  I may move it closer just to see what happens.  What S/N ratio am I looking for?

[Guest]

Signal minus Noise = SNR So, -69 - (-94) = 25 dB.  That's not too bad, but 30+ would be much better. When you enable the Guest Network, you are splitting the available bandwidth between the main and guest networks. Try turning off the Guest Network to see if that makes any difference. AirPort Utility - Manual SetupGuest Network tab is just below the row of icons We haven't discussed the possibility of wireless interference from another network or cordless phone. That's always something to investigate as well when wireless is not performing as expected.

[Guest]

So what matters is the differential then.  As for the Guest Network, I have some "g" devices (Wii, Palm Pre and a g laptop) that all run on that as I was under the impression that you didn't want g devices on your n network because it would slow it down.  Is that not correct?

[Guest]

The "main" network is dual band. It has both 5 GHz and 2.4 Ghz components. Devices will automatically connect to the band for which they are capable. So your "g" devices will connect to the 2.4 GHz band on the main network. They will not interfere with faster "n" devices on the 5 Ghz band. The "guest" network is also dual band with 5 Ghz and 2.4 GHz components. You really don't want to enable the Guest Network unless you really have "guests"....my opinion.