@kartoonz
Chk if the 4Mbps is stable...... if ur happy with it then keep it..... OR
If its possible take a new landline number using the 8Mbps Combo plans...... so it will be rent free & u will only use it for net....... u'll get new line wiring..... so tht line will not hav any problems......
I did the same thing at my uncle's place....... his net on 2Mbps was dc'ing every 5mins....... tried everything to fix it but no use....... but now with new line he is running 8Mbps plan with ease....... improved stats & stability..... zero dc's
SNR improved a lot for him..... earlier on old line it was only 11-12db....... new line always gave more than 21db.....
Taking new line is costly..... with Rs.500 installation charges(
Booking) + Rs.1000 over 2 months period in bill