It’s a nice sunny afternoon in the library. So I tried to start a video chat to share this sunshine with her. However, she denied my request. She said that there is a limit on the bandwidth of 1GB per week with the broadband network in her residence.
Bandwidth, is a measure of the amount of data that can be transferred between computers in a network within a specific period.
I’ve been thinking about this for a while: Why do the Internet service providers want to limit the bandwidth? Well, the most reason I’ve heard is that they want to protect the network device from being overloaded and avoid other network users from squeezed out of the information highway.
Hmm, how can they do that by limiting the bandwidth? Let’s take an example in real world. Say there is a bridge on a river and people walk through the bridge from one side to the other side every day. Unfortunately there is a policy from the bridge owner that the bandwidth, the number of times one person allowed to walk through the bridge, is 10 times per day. Sadly, most people need to use the bridge several times only in the morning. It turns out that there are about 100 people walking on the bridge and each person go back and forth 10 times during that time. They don’t really need the bridge for the rest of the day except in the morning. Bridge is overloaded and few guys with bad luck fell into the river because of that.
I think, what the bridge owner really mean, is to limit the throughput.
Throughput, is a measure of the amount of data that can be transferred in a time unit between computers in a network.
It means that, if I am the bridge owner, I don’t care how many time you walk through the bridge everyday. But you must follow the rule that you are allowed to using that bridge for at most twice per hour! So no one will be waiting by the entrance and the bridge is always is good shape.
It’s the same for the computer network. Why can’t they just limit the throughput to, say 256kb per second? Doesn’t that make more sense?