On one of my previous experiments, I did a test where my computer was behind a router that's connected to another router with a T1 link and that router on the far end is connected to the internet. I went on speedtest.net and it says my downlaod speed is about 1.46mbps, which is pretty accurate considering that the T1 (slowest link on my network) is 1.544mbps.
On an experiment I did today, I was doing equal cost load balancing with 4 T1 links. The routing table says that the route to 0.0.0.0 (the path to speedtest.net) will take the 4 paths and each of them has equal metrics so I know that equal cost load balancing is in use to get to the internet. I predicted that my speedtest will give me about 6mbps for download speed since one link is 1.5mbps and there are 4 equally load balanced so 1.5mbps per link would give 6mbps. When I did the speedtest, it says the same thing, 1.46mbps. I tried shutting down 3 of my 4 links and retesting and it gave me the same result. Does this mean that for EIGRP, equal cost load balancing doesn't increase your bandwidth, it just divides the speed of one link and distribute it to each of the links? (0.375mbps per link for equal cost load balancing across 4 T1 links)
I haven't tried OSPF equal cost load balancing and EIGRP unequal cost load balancing yet so if anyone could give me info on those that would help too
P.S. My internet speed that I ordered is 12mbps. With no T1s in my network I usually get a speedtest of about 22mbps+ because my ISP allows bursting. At the same time of this experiment, I have another computer connected to the internet with no T1s in the path and speedtest says that computer's download speed is 23.44mbps. Other than the T1s, every other cable is ethernet, and all my routers have fastethernet speeds of 100mbps