I firstly found the problem when I was having a call using skype. The call was interrupted for few seconds in every few minutes. I then set up a job to ping the default gateway which is on the broadband router. I found that ping lost for few seconds in every 3 minutes.
The following picture shows the ping result to the default gateway.
Here is the details of the router. REBOOTING doesn't help. PLEASE DON'T ASK ME TO DO IT AGAIN.
|Symmetric CPU Threads:||2|
|Bootloader (CFE) Version:||10.33|
|DSL PHY and Driver Version:||A2pv6F039x6.d26r|
|Wireless Driver Version:||1.363 RC45.18483|
|Voice Service Version:||Voice|
|Uptime:||1D 23H 14M 13S|
my laptop is using static IP instead of DHCP becasue the DHCP server built-in the router is buggy.