MTNL dialup connection not able to connect

[activeashish]

I am having windows vista on my laptop and I am connecting MTNL dialup connection to connect to internet.When i connect after username and password gets verified it gets connected and i am able to see network icon at system try but i am not able to open any site.and page not found error comes .Also it shows limited connectivity.What it means? I am having postpaid connection and it worked fine earlier 3 ,4 dyas back
but for past couple of days i am not able to open any site after getting connected.Pleas suggest if any body has faced the same problem or have any suggestions.
I appretiate your time to read this.
Thanks

[Hitboxx]

/* Moved to QnA */

[hullap]

called the customer care?