what causes my ADSL speed to go down

[Agent_]

i pay for 20mbps
i get 13mbps and 0.7 upload according to speedtest
according to myrouter up and down links i get Upstream Speed 1204 kbps
Downstream Speed 19249 kbps
now comes the tricky part first I tell you how I set it up
------tellephone 2wisted pair line ------- 2 wire rj11 -----router
I dont use the telephone so i removed the filter it is now connected directly to the router by the rj11
my problem is I get disconnected sometimes and router and speedtest value goes down by a LOT
IF i restart my router nothing would change same slow speeds
but if I short the line few times , router disconnects again and i get good old speeds , i might be crazy but am out of patience ill call them sunday till then I wait and see if someone knows why this happens .

 

[Alabalcho]

This means you have problems down the phone line, or at your ISP' equipment.
Make sure all phone line connections under your control are dry and tight.