UT300R2U Modem frequent disconnection problem in bsnl 500 plan

hi
i am using ut300r2u modem given by the bsnl,my plan is 500c,and i am havin frequent disconnections,i.e ten time every 20minutes, kindly anybody give me sugesstions

just use the configurations for ut 300rtu modem

am using ut300r2u modem given by the bsnl,my plan is 500c,and i am havin frequent disconnections,i.e ten time every 20minutes, kindly anybody give me sugesstions