I'm sick of these kinda threads. Seriously. I've seen several since BSNL BB was introduced around 7 years ago.
First of all, speeds higher than 2 mbps, or 256 kBps, is impossible in a 500 plan. There are 2 possibilities where the impossible can be possible.
1. BSNL is testing new speeds. I've witnessed this myself when BSNL BB was new, and was testing their 8 mbps connection. It still went back to normal after a day
2. Burst speeds. They can happen for a brief amount of time, and are mistaken for being miracles from god.
@varad, @gopi_vbboy
Bridging is used to extend a connection to another. Not to combine two connections. You cannot combine two connections using software. Pure and simple.
Why? The short answer is, 2 connections = 2 ip addresses. Only specially programmed software can use both at a time. NOT uTorrent or FDM or whatever.
So, how do you use 2 ADSL connections together? you need 2 connections = 1 IP address. You obviously need a HARDWARE solution.
There are multi-input routers, where you can plug in more than one ADSL line. Then there's the option of using a third router, plugging in the ADSL modems to that router. That would subnet the computer, and both ADSL modems to that master router, which has only one IP address. Bingo.
There are many techniques to increase connection speed, but only by a very very small percent. You cannot expect a tortoise - to - rabbit transformation. If you need more speed, shell out Gandhi photos from your daddy's wallet

and buy a better connection.
I'll try to post those techniques later... most of them are covered in this forum somewhere, I remember making a post like a year or two ago. I'll see what I can dig up.