ASUS RT-N12HP_B1 appears to be blocking downloads

[Saji]

Hi

I have an issue that my router Asus RT-N12HP_B1 appears to be blocking downloads.

Previously I was using service providers wireless router, and it was working fine. Now I moved to Asus and started downloading issues. I can download small files completely rest of them will failed in between. "Failed-Network Error" messages are getting that time. I tried to resolve the error by resetting and updating Routers firmware also.

The current firmware version : 3.0.0.4.378_7449

Any other ideas to try to diagnose this problem?

Thanks in advance