HOW TO TELL IF YOUR ADSL LINK IS FAST IN GHANA

A Summary of the Dsl statics on ADSL

  courtesy of MAXCOM WIFI


Although what is monitored and the exact name may be different depending on manufacturer, the overall information is pretty much the same. Below are some of the common terms and measurements used to judge line quality. Remember these are not hard numbers but simply a generalization of line statistics:

SN Margin (AKA Signal to Noise Margin or Signal to Noise Ratio)
Relative strength of the DSL signal to Noise ratio. 6dB is generally the lowest dB manufactures specify in order for the modem to be able to synch. In some instances interleaving can help raise the noise margin to an acceptable level. Generally speaking, as overall bandwidth increases, your signal to noise ratio decreases. So a customer that upgrades from 1.5 to 6.0 service will typically see a corresponding decrease in the signal to noise ratio. The higher the number the better for this measurement.
6dB or below is bad and will experience no synch or intermittent synch problems
7dB-10dB is fair but does not leave much room for variances in conditions
11dB-20dB is good with no synch problems
20dB-28dB is excellent
29dB or above is outstanding

Line Attenuation
Measure of how much the signal has degraded between the DSLAM and the modem. Maximum signal loss recommendation is usually about 60dB. One of the biggest factors affecting line attenuation is distance from the DSLAM. Generally speaking, bigger distances mean higher attenuation. The lower the dB the better for this measurement.
20dB and below is outstanding
20dB-30dB is excellent
30dB-40dB is very good
40dB-50dB is good
50dB-60dB is poor and may experience connectivity issues
60dB or above is bad and will experience connectivity issues

Four tools for checking bandwidth

The question of whether you're getting the bandwidth you pay for is one that just doesn't go away. Twice in the last few months I've suspected my ADSL connection of running slow and, sure enough, despite the modem telling me I had 3Mbps down and 500Kbps up, for whatever reason, restarting the modem fixed the problem


I personally blame Vodafone Ghana for not cleaning the bits as they route them to me and because of that my modem is getting a build-up of digital residue.

But testing your connection isn't hard; you can, for instance, use a service like Speedtest.net published by Ookla and let them do the work.


Ookla's Flash-based app figures out where on the 'Net you are, which of their test servers are nearest you based on ping time, and then uploads and downloads large files to measure throughput accompanied by cute graphics (which shows what looks remarkably like a man peeing on a pyramid ... but I digress).


Speedtest.net tests your connection throughput using a man peeing on a pyramid.

As you can see from the screenshot, my download and upload performance figures are roughly in the expected ranges, though the scorecard (see image) rather depressingly tells me my connection gets a rating of D-minus and is slower than 77% of other U.S. connections.
 


Speedtest.net scorecard

Speedtest.net also has a free iPhone app (which is iPad compatible) that does much the same thing but obviously not using Flash (in case you're not aware, Apple doesn't allow Flash to run on iOS for a number of good reasons, including stability and security issues as well as the fact that Steve Jobs loathed Flash).





Speedtest.net for iOS running on an iPad

The iOS version of Speedtest.net looks much slicker than the Web-based version and, unlike the Web-based version, you can choose which test server to use. Curiously, the app consistently gives slightly lower throughput values which is, I suspect, due to performance issues with bulk data transfers over Wi-Fi (the interface also has an "easter egg" ... "pull down" on the meter when not running a test to see a demonic-looking kitty).

The few reviews of this app complain that it isn't accurate, but I found it to be in reasonable agreement with its online sibling.




The Speedtest.net iOS app reports consistently lower throughputs probably due to Wi-Fi.

Another connection performance test app I like for its presentation is Speedtest X HD (there's a free version and a Pro version for $0.99) published by Veeapps, which also appears to yield similar results to the other tools already covered.

With Speedtest X HD you can select which server to use (a few of them are only available with the Pro version) and it provides an interesting display of global performance stats. You can also add your server, though what's involved in this is not explained in the app or on their site which is, as of this writing, broken. This makes me hesitant to recommend the paid version.




Speedtest X HD running on an iPhone

Of course you have to be careful of casting aspersions on your ISP's service when using these tools as they will only give accurate results if your connection isn't being used by any other applications or services. This is where cloud services can fool you as many run in the background and, while they may adapt to changing bandwidth usage by throttling themselves, they'll still make your connection look slower than it actually is.

A few weeks ago I wrote about AppNeta and their multi-site WAN and LAN performance management suite and how they used a fascinating technique called Packet Dispersion Analysis to test and characterize network connections.

To refresh you: Packet Dispersion Analysis sends a sequence of small packets of varying sizes and configurations to a test server and back again. By analyzing how these packets are delayed and routed by the network it's possible to determine the latency, the available bandwidth (or "headroom"), the actual bandwidth used, and how well certain protocols (such as VoIP) perform.

The beauty of this technique is that Packet Dispersion Analysis requires only a tiny fraction of the available bandwidth to work (with AppNeta this is only 20 small packets) so it can be run while routine network operations are in progress without causing any noticeable bandwidth impact.




AppNeta's PathTest iOS app running on an iPad

AppNeta has just released a new free iOS tool called PathTest that uses the Packet Dispersion Analysis technique and which appears to give more accurate results than any of the other tools I've tried (what is consistence are my upload speeds, while download speeds, where Wi-Fi is the "last mile" -- OK, last few meters, but you get my point -- are subject to more complex network effects and so appear to vary more).

While this may not be the sexiest user interface compared to the others in this column PathTest provides far more detail and more accurate results. A future update of PathTest promises to scan your local network and automatically find and save PathTest targets. PathTest has to be my favorite connection performance test I've found for iOS so far and gets a Gearhead rating of 5 out of 5.


Advance users can also use PRTG or Solarwinds to check bandwidth setting

User can email me for support on that.