Having said that it should be noted that:

In almost every case of a reported DSL difficulty, in almost every instance, optimal  service quality can be found at the point where the line in question (from the street) ‘hits’ the protection module for the dwelling.   This is easily determined when tested with a laptop at the side of the house.  You can call and have this test performed on site for a nominal fee.  Email me anytime for a diagnostic test of your DSL service.  (usually same day or next day service).  Don't forget to input your location, even if it's approximate.

(Note:  although apartment units will be somewhat different, facts about wiring remain the same).

 DSL is, amazingly enough, quite forgiving of ‘less-than-optimal’ wiring and practices associated with home telephone wiring.  Passing the 'Point of DSL Forgiveness' will show as either ‘poor performance' or 'no performance' inside the house.   Two of the most common 'cripplers' are:  the common 'Dialer Alarm' (panel) and/or apartment complexes with Type 'A ' Enterphone systems.  These devices are always positioned between your  jacks (access points) and the incoming Telephone line.   (I know what you're thinking... but WAIT!  Don't pack it up and take it back!).   There are quite acceptable resolutions:

Dialer/Alarm systems:      Firstly, find out if you've got one..... you may surprise yourself!  (see below)

Whether you have your home 'monitored' ...or not*...  (*eg:  perhaps you've moved into a house where the previous owner used an alarm device and monitoring  service)  you may, unknowingly, have one of these Alarm panels 'camped' on your (DSL)  line, which usually means that the line is passing through the circuitry of the alarm panel en route to the jacks.   This, without doubt,  'taxes' your High Speed DSL service, even cutting it off at 'check-in time', once during the 24 hour day.   Go looking for an Alarm panel and the (telephone line) 'isolator jack' which is usually situated quite near (or within) the panel.   With due diligence, you can temporarily 'unplug' the panel, thereby allowing an 'unfettered' line (and DSL signal) to go through to the jacks and your ADSL modem).  

Amazed at the increase in the quality of your Internet service?   Thought so!   Now, you can do one of two things:

a):     If you are NOT paying for 'monitoring' - then you have the option to leave the alarm panel detached from the line  (This does not affect and is separate from your perimeter alarm).  

b):   Note of CAUTION:  For those paying for home monitoring:

  If you ARE paying for 'monitoring', chances are the alarm uses the telephone line to call out.  Always plug the grey 'patch' cord back into its (RJ45) telephone jack/receptacle. 

Then phone me about the way you'll be able to retain DSL service 'optimally'  and keep your alarm monitoring system intact.

       Your Telephone company prides itself in the quality of its plant/service infrastructure. 

  Type 1  or…  Type 2 ..and variations (all of which are plastic). 

However, no Telephone Line Protector module was ever created with the idea of defeating a would-be burglar.   An alarm security 'dialer-type' monitoring system (uses one's telephone line) is always weakest at this point (usually at the side of the house) as the telephone line can be easily severed here with the simplest cutting tool.   Read your Alarm contract 'fine print'.

For more information on how you can best protect your (Monitored) Alarm system wiring at the least cost,  go to

http://www.LineCutProtection.com  

Beyond this point lies the ‘tricky part’ for DSL.  Going into any dwelling along existing wires, your High Speed service can degrade as it ‘fans out’ over what can be much like a spider-web of telephone wires going to the rooms and jacks inside a house.   

In particular, the DSL signal, in lay terms, does not like passing through alarms circuitry and/or enterphone systems circuitry on the way to the modem.   (It likes a 'clean, unfettered line' feed, direct to the modem).    Your DSL service can be tailored to suit these appliances.

   What is the device that ensures 'optimal' DSL service to the modem?:   

 The Wilcom or Comtest 'in-line' ADSL splitter module (fig. 1)  Used for  retaining optimum incoming DSL signal to the modem on lines with (or without) dialer alarms and/or enterphones.    Cost for one of these devices is less than $20.  Installation time and configuring of one of these units is usually 1 hour.   Note:  Using one of these splitters renders those four quick-connect filters redundant (you get to pack them away in the box they came in).   You have to decide that 'optimum' signal strength is important to you and that leaving your DSL modem fixed in one location in the house is not a problem. 

                                                  fig. 1

(Note about abandoned wiring:  You may also have defective, ‘junked’, or redundant wire attached to your line that you’re not aware of,  eg: left during the course of renovation works of past years.  

Here’s an example of a jack which had been left abandoned, fallen down, forgotten about (…and still alive!) in a crawlspace from the days of the ‘old’ kitchen above.  This one was left from a renovation done 10 years previous:                    

(complaints to 611:  Not-out-of-Service, Noise-on-line’:   ‘static’ ongoing for five years, and  “just when it rains and the wind blows”, the customer says.  (Or, sometimes the wires are actually bare and/or sliced, (the jack long-gone), and here we see the live feed wire dropped down through the floor to the sand-or-concrete ‘pad’ below.. (“Oh yes… new ‘baseboard-and-carpet’ work was five years ago when we moved in and we told 'the guy-doing-the-moulding' that we didn’t need that living room jack”).  It got cut, You move in and... guess what’s going on under the floor..!

Trade note:  As long as these abandoned ‘live’ runs are damp and 'noisy', a qualified, professional Telephone worker should be able to detect these and remove them from the Network.

Some other impedance considerations: 

You may quite simply have Jack ‘pins’ that have become corroded.  (Perhaps a drink got spilled on/into the jack at some point in time.  Or, you’ve done some wallpapering and the jack got wet that day.  (Time to get down on your knees (with flashlight-in-hand) and check the condition of the jack-pins…  a 'huge' source of troubles in this business!)

*Network Interface Device (see FAQ’s on the Homepage for explanation)