I had already posted queries on setting up wifi router to local cable ISP and again having a problem after configuring TP LINK MR3020 to Alliance broadband (Kolkata) providing me a static IP. Well I could configure the router and was getting access to the login page and also could browse with full desired speed for an hour or two but after that the speed gradually got decreased. I have tested the same with my previous router TP LINK WR740N and it had the exact same problem and so I sold it out. Now with this mini router TP Link MR3020, I have tested with another ISP but there it worked properly. What may be the problem as I know I did the configuration right. Also I tried with changing the MTU size from 1500 to 1480 and 1460. Please help me out. Is the ISP doing such mischief or is there any further configuration that should be done??