Bandwidth

This has puzzled me for a while.
If I go to say, the NASA site, and click on a link to view a huge 2meg picture, obviously the image comes down the pipe and into my machine. Now it’s a big picture, and it takes a few seconds to load. I have just consumed 2meg of NASA’s bandwidth. This I understand.
If though, 2 hours later, I decide to go see that picture again, and I click on the same link, and I get the same picture, the picture will come in almost immediately because IE retrieves it from the cache. So I’ve not actually cost NASA anywhere near the 2meg again have I ?
If that is the case, and people are not clearing their caches very regularly (I do mine weekly by the way along with all the other cleanup jobs), then repeat site visitors should not cost a huge amount in bandwidth as a lot of the content will be the same. I know you can set IE to automatically check stuff, but in the case of the picture, I just wonder.
I’d say “Is that right ?”, but I think I just confused myself …….

3 thoughts on “Bandwidth

  1. If you download it, then run it, you have a one 2meg download on the hosts bandwidth.

    If you stream it live (which is slightly different to an image, which is static, if I recall), then you are hitting some bandwidth each time (has to be compared to your local cache to ensure it’s not changed), and if more than one person hits it at once, then you all have to contend.

    Take that movie I have hosted on my machine. I only have 30k/sec upstream, more than a couple of people try and stream at once, it’s going to affect them all and be choppy. More than one person downloads it? It simply slows down instead.

  2. There still has to be a request to the server, which = bandwidth. Plus local caches only last so long, no matter what settings you give it, so it’ll need reloading eventually, wheras running it locally doesn’t

Comments are closed.