basic networking question

Can uploading data affect the speed at which you download data?

i.e. if I’m downloading a file, and then start uploading a file at the same time, could the download speed decrease?

I seem to recall that cable modem and DSL services actually allocate a separate frequency range for upstream and downstream connections, so it seems like it wouldn’t make a difference, but what about with a good ol’ fashioned dial-up modem? if I have a 56k modem, can I (theoretically) push AND pull that much data off the wire at the same time?

Hrmm… generally with a broadband connection there’s a separate upstream and downstream limit. This is referred to as a capped connection. So with these broadband connections you’ll have a separate limit for how fast you can download and how fast you can upload. Now for a dial up connection, they usually bunch the two together, and the bandwidth is distributed between the two. So for a 56 Kbps modem, you may be downloading at 40 Kbps and uploading at 16 Kbps (ideal circumstances). So no, you won’t be able to UL and DL 56 Kbps on a dial up, but you may be able to UL 28 Kbps and DL 28 Kbps at a time.

Uploading will degrade your download speed just a little. Uploading requires a little communciation between the server and your PC, so that you use up a little download bandwidth doing the upload.

Melraidin is correct for the most part. Uploading at 28kbps will cause your download to go to almost nothing, I’d like to see sombody get 2k up and 2k down on 56k. As for DSL and cable, Yes the download and upload stream are seperate, however your ISP may not allow full upload and download simultaniously. My very BAD isp will allow only half my rated download speed if i am using half of my upload speed. IE my rated line is 758/128, if I used 64kbps upload I would only have 384 download.