ADSL testing in the field

Investigating a problem for a client required documenting the current adsl2 and adls2+ line performance as a means of understanding some performance issues. Initially checking the available services through SamKnows for the two BT lines gave some odd results. The two lines were based in Runcorn in the UK and a visit onsite was arranged. The client uses a Vigor 3300 with two Vigor 110 adsl modems to provide vpn and internet access in a fault tolerant arrangement. However this does raise an issue where it is harder to monitor the  modem perfomance and the line characterisitcs. It was planned then to use the Vonaq tester – a quicktest 500 to compare the values obtained from the modems with direct test results.

To test the modems values you attach a laptop wired connection to the lan port of the modem with DHCP set for the card. This picks up an address in the 192.168.1.x range from the modem and allows browsing to the modems web page on to see the line characteristics. These values for synch speed / upspeed and SNR / Line Attenuation values were noted. Then the Vonaq was used to test the lines directly by connecting the adsl cables and switching on. The vonaq then indicates any issues that it sees through the leds on the front panel – but more tellingly the details of the test results can be viewed.

In this particular case the problems relate to low snr and high (40+) line attenuation values. We were also able to test the line values for two neighbouring locations – and we actually able to show that the client was getting substantially less speed than they believed and they are going to take this up with the providers. So good result for them in return for allow us to test the circuits.


Once again the Vonaq showed unequivocable evidence of the line characteristics on the adsl2/2+ lines and provide an approach to resolve performance through observation. All that in a handy portable tool.