Q: Diagnose/improve Airport wifi network

Make sense?

Makes perfect sense.  First, we assume that the Express is extending the network by connecting using wireless back to the AirPort Extreme, correct?

When you "extend" using only a wireless connection and you connect using wireless on your Mac, you will typically lose about half or more of the speed on the network.

Why? The wireless has to make one "hop" from the Airport Extreme to the AirPort Express. Then it has to make a second "hop" from the AirPort Express to the Mac using wireless. That will take up a lot of overhead or bandwidth.

When your Mac is connected directly to the AirPort Express, the wireless has to only make one "hop", so you regain the  speed or bandwidth that is lost when the Mac connects to the Express on a second wireless "hop".

Want to improve your network?  Connect the AirPort Express back to the AirPort Extreme using a wired Ethernet cable connection.  There is zero loss of signal speed through an Ethernet cable......up to about 325 feet or 100 meters.....so the Express gets a full speed signal.....rather than a slower wireless signal.....because the wireless signal slows down the further that it must travel and also slows down if it encounters any obstructions in the signal path....like a wall or ceiling.

When web sites take a long time to respond and fill the page is that the download or ping or both?

Could possibly be both, but usually is a DNS problem. Try using the the Open DNS servers or Google servers to see if things improve. Typically, these are better DNS servers than the ones that your Internet Service Provider is using.

I have an Airport Extreme connected to the Charter modem downstairs.

 

Upstairs in my office I have an Airport Express with a printer connected via USB.

 

I believe I have the Express correctly configured to extend or expand or whatever the network.

Just so you are aware, using a wireless connection between base stations in an extended Wi-Fi network is bound to provide the least overall bandwidth performance. This is not unique to Apple products.

Ideally you would want to connect them by Ethernet. However, this is not always possible or ideal for every situation. An alternative would be to employ powerline adapters. These would create a pseudo Ethernet network and be the next best scenario for performance.

My MB Air sits on a desk about 7 feet from the Express in my office.

 

If I connect to the Express via Ethernet to USB connector to MB Air, my download speed is about 65 Mb/s, upload about 4 Mb/s and Ping about 31ms.

 

If I connect via wifi, the download drops to about 20 Mb/s and the upload and ping stay the same.

 

Make sense?

The extending AirPort Express can only extend the Extreme's Wi-Fi network at the bandwidth that it receives. So, your MBA may see its connection with the Express with a full strength signal, that signal may have poor bandwidth (available speed) to be of much use.

When connected by Ethernet you, at least, eliminate one segment of a Wi-Fi network and should notice some improvement in performance.

Anything to improve wifi?

Yes. Use wired connections between base stations. If not possible, use powerline adapters instead. Finally, if that is still not an option, try placing the extending Express in a location where the signal quality of the Extreme is still high enough for the best possible bandwidth. To figure out where that you be, take a look at the following AirPort User tip on optimal base station placement. Please post back your results.

When web sites take a long time to respond and fill the page is that the download or ping or both?

Sort of. Download data transfer rates are dependent on a number of factors and are accumulative. Some of them are:

• The web site host ability to service multiple requests.
• The current Internet conditions.
• Your ISP's ability to provide you with a specific download "speed."
• Your modem.
• Your router.
• Your Wi-Fi network.
• Your computer's Wi-Fi card & network configuration settings.

Ping is one measurement and is designed to give you a snapshot of the overall latency between two devices on a network. Internet speed testing apps use it to show latency between your computer and the web-site host server. As you can imagine from the factors I provided above, there are many hops between those two locations that can affect data transfer latency ... but Ping alone is NOT an accurate test and should not be depended on alone.

The following two references may help give you a better idea about measuring network performance:

• How Fast Is Your Network? - SmallNetBuilder

• Measuring network throughput - Wikipedia

The other thing that can cause long delays in web page loading is DNS. DNS can be thought of as the Internet's Yellow Pages. If you have the wrong phone book or it is out-of-date, accessing a site can be delayed. By default, your ISP will provide you with their DNS servers for this service. However, what they provide may not be the best performing servers in your situation.

To get an idea on making DNS server comparisons, you can use an app, like Namebench to find the best servers for your location.

Bob,

I have an AirPort Extreme with a an AirPort Express for my stereo connected wirelessly. I also have a “barn” that extends my network wirelessly using an older Extreme. I also have an Express wirelessly connected to the barn Extreme for a stereo out there.

That's AirPort Extreme . . . House Stereo Express

                                      . . . Barn Extreme . . . Barn Stereo Express

I also have been running two iMacs, a PowerBook (or two), Canon printer, iPad, two iPhones, and an AppleTV off the main AirPort Extreme. Unfortunately, I live in the middle of nowhere and the “best” DSL speed I can get is 3Mbps. Will connecting the iMacs to the AirPort with Ethernet make any real difference in my case?

Z