you need to be sure that no one other than u i using the connection. note that, background software update (like phone update, windows update etc) will interfere with the speedtest results.

since your attained rate is quite good, around 5mbits. id like to think that it is either from your side, or the speedtest server. plus, not all speedtest server have highspeed link to our tm network. so, if ever get anywhere around 3~4mbits from any nearby speedtest server. your internet connection is considered ok.

maybe, maybe not. ive done rewiring. still same.

weird that my next door friend, got no problem with same speed. ive tried her modem too, not much differ. disconnection still occur at random time, especially when the speed reach the maximum subscribed speed. possibly something is wrong at their exchange.. :/