As this is an Unlimited plan, downloading at higher speed 2 Mbpsafter exceeding FUP, due to faulty software at BSNL end, the user may get an advantage for say 24 hours additionally.Reminds me of NU earlier, when full data download was billed , if download started earlier to 0200AM. and continued by user .without restarting modem.Also some users started at 0755AM and continued FREE d/l upto 0830AM etc.These bugs have been FIXED, and meter records data usage separatelyfor NU period for U/l and limited users equally.( in most self care portals)Over Billing complaints drastically reduced or almost NIL now metering stops/breaks restarts at 0200AM and 0800AM. PARA 2:Changing server speed midway may be also possible.How Changing SERVER IP will reduce the speed not known.. May be the Summary Usage is checked later ( every 24 hours )or at start of a sessionand a command made to allot a server for the lower speed.Other side of the story: sometime users may not,get back the 2 Mbps /4Mbps, at start in next month and the speed remains at 256 Kbps.!Software programmers may be able to explain, about DSLAM equipment.