It is possible to increasing the internet speed in mozilla firefox.there is a simple trick that is used increase the internet speed upto 50% extra.
now follow the steps to increase the internet speed
step1:
Type "about :config" in the adress field.
step2:
Set the value of network.http.pipelining to "true".
step3:
Set the value of network.http.pipelining.maxrequests to "100".
step4:
Set the value of network.http.proxy.pipelining to"true"
step5:
Set the value of nglayout.initialpaint.delay to "0"
thats all now check your internet speed.the speed is increased compared to normal speed.if any problem then comment here