Downloading speed problem

Asslamoalikum

i,m using shiro ADSL2/2+ ethernet modem with 1mb speed since 2 month but nearly 1 week ago i have problem with downloading speed..normally i got downloading speed 100kb but now a days i got speed maximem 20kb..i have been tried many times to reset router and setting but prb is still there...

Stranging thing is this that i have another spare linkdot net Aztech DSL605EU router when i connect this router with ptcl broad band setting it,s work properly with 100kb speed..i,m sick of this prb and not get any solution from many dayz..plz anyone help me..i shall be very thankful to you for this favour..

umm why don't you just stick with the Aztech dsl modem slave?

bcoz i will give this back to LINK DOT NET company..so plz anyone give me solution

How you setup Aztech Modem with PTCL DSL, i did best to get connect via Aztech to PTCL, Connection Status says ok, but no browsing with Aztech on PTCL Dsl./

Any setting detail u may provide