When we talk about quality DSL (ADSL and VDSL) connection, it is impossible to link this issue is IPTV problems. Very often, users on each pair uses IPTV and Internet, all over a single DSL modem. Therefore, the very common problems in the functioning of the IPTV service as well as Internet access. This is usually manifested in the form of a pixel image on a TV, as well as interruptions or inappropriate speed DSL, or the speed of download and upload.
The following illustration shows the appearance of the picture on the TV when a pixel. The figure appearing dice, loses tone, occasionally can come to a complete breakdown of the video signal.
The causes of these problems may be different, but the most common are: household installation, DSL modem, digital subscriber line (whether it comes to air or underground network), and very rare port on the DSLAM.
What is characteristic for ADSL service is the fact that to maximize potential flow decreases with increasing distance. Therefore it does not matter where you are in relation to the switch nodes (DSLAM). For example, if you are from hubs are more than 3 km, almost certainly is that IPTV service can not be used. Therefore the interference susceptible users on these „border“ areas, where the maximum possible bit rate user pairs very close to flow or service used by the user.
Besides the above mentioned parameters, it is worth mentioning the so-called noise margin SNR, which is a very important indicator of the state of DSL lines. What is the practice showed noise margin below 12 dB may indicate problems in the DSL service.
As mentioned one of the problems can be alone DSL modem, and sometimes its adapter. By replacing the modem or adapter solves the problem.
One possible cause is the access network (underground or air). Poor connection or contact with another pair, somewhere on the line might be causing the problem. Locating faults or replacement pair solve the problem. It should be noted that the characteristics of the cable in the access network (underground) significantly affect the quality of DSL lines. Newer networks built with underground cables, type xDSL have a much better spec, and the interference less.
Poor household installation is perhaps the most common cause of interference on DSL services.