username password mean not on the portal.
It username password given at the time of registering on network.
if modem is connected via pppoe mode(as soon as u swaitch on pc and modem,u r connected to net),username and password reside in modem
,if its connected over brigde mode (u hav to dial username and password).,its in dial up connection properties
th username which ends with area code something like 123_hyd or 234_vja like that
that username and password has to be used in data.bsnl.in