A useful Test for Bandwidth and Latency

Test Latency

This page can be used to test latency of any Internet connection. It will show the bad ones as bad and the good ones as good.

Ideally people live in cities and towns that are properly connected to the Internet via broadband cable services that offer great speed and convenience at a low price. However, not all of us live in cities or towns and we do not have such urban amenities. Consequently we need to find ways of reaching the Internet that are faster than a 28.8 Kbps telephone dial up account. There are two or more ways of accomplishing this goal in our area West of Austin, Texas in the "hill country". One way is satellite ISPs and the second is by radios using towers like cell phone towers. Which is faster in bringing up a web page? Satellite ISP service or microwave?

This page provides a semi-test of latency during a download of a webpage from a satellite or ground connection. Latency, in this case, means the time necessary for all file executions to occur for a complete web page to appear on screen. Latency is not problematic for ground based ISPs and for downloading most text pages regardless of ISP, either satellite or ground based ISP. However, pages with many small graphic files can be very slow to download, because a separate file request is issued for each file, whether it be text, graphic or other. With the great increase in graphic files on web pages seen in the last few years, latency has become a time consuming issue, especially for satellite internet connections. Tests on this page are specifically useful for checking total download times from satellite ISPs such as Direcway and Starband as well as ground based ISPs.

The tests always give the total time required to download a page and do not break up the results in a way that can be used diagnostically, which is best done using ping and tracert (see below for directions).

Even though there are blisteringly fast satellite download speed available, latency can greatly slow presentation of a complete screen, often resulting in speeds equal to a dial up account. Latency effects occur using satellite connections due to the distance to (22,000 miles) and from (another 22,000 miles) geosynchronous satellites. The signal travels at the speed of light (186,000 miles per second), yielding a theoretical minimum 0.23 seconds (230 milliseconds) latency for each file request. A second component of the total amount of time required for a page download results from the momentary demands for bandwidth, which can vary greatly depending on the number of users and workload. There are times of the day when bandwidth is scarce and times - often late night and early morning and weekends - when it is more plentiful.

The following three steps allow the calculation of the "momentary" latency of your satellite ISP.

       First, click this graphic. A new HTML file will open that contains one-hundred identical 5.734kb BMP files, each having different file names. Consequently, each of these files is separately downloaded. Measure the time that is required for the page to completely open.

       Second, click to clock the download time of a single large graphic image (575 KB) of the first page above.

       Third, subtract the second download time from the first download time to get the momentary "latency" (time measured in seconds) of your satellite ISP.

Also click to see 100 copies of a single file open on a HTML page. This tiny 5.734 KB file is only downloaded once, and this test is mainly a measure of how fast your computer can display it 100 times on your screen.

Dumping your browser's cache is necessary for valid repeated tests. Occasionally, downloads will get "stuck" and not properly complete a page. Clicking the "REFRESH" button on your browser will "unstick" the download. Or, right-click on the graphic and click "show picture".

Some momentary latency times found are:

  • My Starband ISP (satellite ISP) connection speed on Saturday, November 13, 2004 at 10:00 A.M. was 66 seconds. Another test at 10:56 resulted in a 105 second download, with one graphic not loading. Another test at 11:48 completed in 56 seconds. A 6:50 A.M. Sunday morning test resulted in the lowest latency of 39 seconds. The second graphic file downloaded in 9 seconds each time Saturday morning, and in 6 seconds Sunday morning. Subtracting and averaging these figures results in an average 67 second latency, or 670 millisecond latency for each of the 100 files. This is comparable with other estimates of satellite "latency" at about 500 milliseconds (1/2 second) per file. This is too slow for me, particularly at the price for the service, so I remounted my Starband dish in this more appropriate way. Consequently, a very large part of the delay using a satellite connection is latency due to the long distance the signal must travel through space, although there are other ground based causes of slow satellite connections.

    Tests for land base ISPs are also useful, although test results show the sum of all latency issues, mostly of a bandwidth nature. Usually the ISP gets blammed for slow connections, but there are usually many hops to the web page you want opened, and any of them could cause a slowness problem.

  • My neighbor's Zeecon ISP (wireless) latency on Sunday, November 14, 2004 at 5:30 P.M. was 10 and 13 seconds for the 100 file download, and 11 and 12 seconds for the single file download resulting in a momentary latency of 0 seconds.
  • My friend in Richland, Washington, with his Verison DSL connection posted a download time of 15 second for the 100 file download and a 7 second download time for the single file, for a momentary latency of 8 seconds.
  • My friend in Galesburg, Michigan, with her Charter Communications cable connection posted a download time of 10 seconds for the 100 file download and a 8 second download time for the single, for a momentary latency of 2 seconds.
  • My temporary $10.00/month Earthlink 28.8 Kbps dial-up connection produced a 42 second for the 100 file download and a 11 second download for the single file, for a momentary latency of 31 seconds.
  • My new Zeecon connection reliably posted 12 seconds for the 100 file download and 11 second download for the single file, for a momentary latency of 1 second December 12, 2004. As bandwidth is sometimes a bit more scarce, other slightly slower times were also observed during busy parts of the day.
  • As with all good things, Zeecon's connection is subject to problems. In the later few months of 2005, Zeecon's connection deteriorated. By December 22, 2005, my Zeecon connection had slowed down enormously, apparently due to their bandwidth problems and apparent radio frequency interference (jamming) caused by others.
  • Worse, Christmas day 2005, around 3:10, the Zeecon connection went belly up time-wise, posting a 133 seconds for the 100 files and 39 seconds for the single file for a momentary latency of an excruciatingly slow momentary latency of 94 seconds (about one file per second), which is vastly slower than dial-up. Running the Altuit Ping tool shows what is going on over a long time.

All of my Zeecon-subscribing neighbors are now having similar problems with Zeecon's connection, so it is just not my connection. Using tracert.exe, it looks like it is also a Time Warner Telecom problem. Clearly, it is Zeecon that gets the blame, even though there are many explanations for a slow connection, including radio frequency interference outside their control.

Look at the Altuit Ping Utility data to the right. This handy little tool Pings an address, such as Google.com. It keeps a record of each ping, which is presented in the screen on the right. (Click here to download a zipped version of this program so you can test your own ISP from your desk top.) Look at the average Ping times for Zeecon's connection on the right side, another measure of latency. They vary wildly and they timed out many times earlier today. The Zeecon connection has staggering second long Ping times around 2 P.M, apparently from some outside radio frequency interference..

Here is a larger sample of the times posted for the Zeecon connection to Google.com using the Altuit Ping tool. Notice that there are frequent packet losses varying from 25% to 100% with time outs. Scroll down the list to see them all.

On January 2, 2006 we switched ISPs to TexasData.net. This system uses a different frequency and seems to produce highly replicable ping times to google.com. These times are slightly slower that the Zeecon times when Zeecon performance was at its best in early 2004, but it is much faster than Zeecon in its late 2005 deteriorated condition. Also, upload speeds for TexasData.net are twice as good as the fastest Zeecon upload speeds. Notice from the ping times below that there are exceedingly few packets lost and no time outs.

Back to satellite connections. Perhaps the best reason to avoid a satellite connection is the very slow upload speeds required for building graphics intensive web pages or sending email with lengthy attachments.

In late 2009 we were finally able to get a Time Warner high speed business-class cable internet connection. Our momentary latency is now one second (3 - 2 = 1). Any questions?

Here is another speed test using BroadbandReports speed test.

Standard ways to test latency are to use the "ping" and "tracert" commands from your C: prompt. In Windows, Click "Start", "Run...", type "cmd", then type "ping www.google.com" or "tracert www.google.com" (or some other known high speed site), and read results for various hops. The first one is from your computer to your router, the second is from your router to your ISP (unless you have more than one router), and the following are various hops along the way to google.com.

Contact George Eby in Austin, Texas, to have your times and ISP posted.



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