ADSL Service Slowness

[#1]

Dear Guys,

A couple of weeks ago I configured an ADSL service using a NV340, everything is okay with the pppoe link and seems to be access to the Internet, however here is where the customer is reporting me that the service is slow, the computers can only reach google.com and when they type other websites it never loads.

We make a test using the router from the service provider and when I connect the ADSL to this modem, all the computers on the LAN can reach the Internet very fast.

Would you help me?

Attached is my config file.

Thanks,