It is definitely Lanka Bell...
Coz, they give you 100 hours of internet, which means you pay only for the call charges...
And the call charges are only 25 cents per minute because it is a local
lanka bell host number that you'll be dialing...
And since it is wire less (CDMA) it tends to be more faster and robust than SLT, where in SLT it usually disconnects easily, and besides all that, SLT ahs given the lowest priority to dialup users over all its ADSL and commercia/coprtperate customers, so what you get from an SLT dialup is far worse than crap...
But Lankabell is much better than that, you'll find its much cheaper and of higher quality (Compared to other similar services)...