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ADSL - Synchronization issues: the causes

October 2015

Expanded use of Broadband is creating congestion in the network including service cuts, disconnection and ADSL synchronization. For transportation of data through telephone lines, high frequencies are used between router NRA and modem. The signal is defined by three elements, viz. speed synchronization, margin of the signal noise of around 10DB and the mitigation which depends solely on the connection of the telephone. Use of telephone extensions must be avoided as attenuation is increased. Electromagnetic environments must be strictly avoided. ADSL filters enhance the separation of frequencies between telephony and ADSL. To improve ADSL signal synchronization, it must be connected to the main outlet.

[ADSL] Synchronization issues: the causes

With the expanded use of broadband there is a recurring problem causing disconnections, service cuts, and ADSL synchronization.


What is ADSL sync? To transport the data through your telephone line, ADSL uses higher frequencies between your modem and router NRA (your ADSL central). Depending on your location relative to the central function and also airlines, you will get a signal that is defined by three main elements:
  • The speed synchronization (also called debit ATM).
  • The margin of signal noise. To put it simply, ADSL uses a frequency band. The margin of signal noise is the difference between the highest point of the band, which is deducted the noise on the line. It remains a margin, typically around 10 DB.
  • The mitigation. The latter will vary depending on the quality of your telephone line and your connections.

Connections: the good points to check
  • The telephone extension. Completely banned: to connect your ADSL modem. Indeed, the extension telephone will capture all the noise surrounding your home. This will create an increase in attenuation on your line, causing a disruption in flow or a complete loss of signal ADSL.
  • Electromagnetic environment. ADSL modems are generally very sensitive to their environment. Avoid putting your modem close to: DECT, halogen lamps, loudspeakers, amplifiers...In short, anything that can emit radiation.
  • The ADSL filters. The ADSL filter will allow the separation of the frequencies used by ADSL and the telephone. It is imperative to install filters to improve your ADSL signal.
  • The main outlet. When France Telecom carries out an installation someone's home, there is always a main outlet, which connects one or more catches. For ADSL, it is always best to connect to the main outlet, with the aim of improving the ADSL signal.

These tips will allow you to have an optimal configuration, which will solve most synchronization problems of ADSL.
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Published by jak58. - Latest update by Celia Gatward
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