bbiandov
join:2001-02-09
San Francisco, CA
| Does upload screw the download speed on Cable as in DSL
Hi everyone,
I was curious-- Does upload screw the download speed on Cable as in DSL. Basically in any of the DSL services I have ever owned, if you set something to upload at the full upload speed (like 384k) then the download is gone, it will mostly timeout, it is total crap. you will be happy if you can get the same (384k) on the download while the circuit is supposed to be 1.5M download. I guess they don't tell you that it is HALF duplex or something LOL
Anyway back to the point - does the same situation occur on Comcast cable?
Thanks
Boyan |
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deblin
Dark Side of the Moon
Premium,MVM
join:2001-09-01
Middletown, DE
| Yes, it does. It is indeed because it is a half duplex connection. If you are uploading at full tilt, then downloading slows down to approximately the same speed you are uploading, since the ACK packets sent for downloads cannot get back as fast, since they are competing for upstream bandwidth with whatever you are doing that's saturating the upload.
There are some commercial routers with so-called QoS or packet queuing which can alleviate the problem (though you won't get full upstream and downstream at the same time). I believe the WRT54G/GS series of Linksys modems either have this ability or you can add this with open-source firmware such as HyperWRT or OpenWRT, etc.
--
"Talk is cheap because the supply is greater than the demand" - Shelby Friedman |
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d_l
Barsoom
Premium,MVM
join:2002-12-08
Reno, NV
| reply to bbiandov
That is simply the way TCP/IP transmissions work. All download packets must be ACKed and if the upload channel is saturated then the ACKs are stalled.
This isn't unique to DSL. There are DSL modems that handle this problem. Don't think that cable has anything to deal with this. |
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NormanS
Premium,MVM
join:2001-02-14
San Jose, CA
 ·Pacific Bell - SBC
| reply to bbiandov
This is not a "Cable vs. DSL" issue, just a common TCP/IP issue. Cable, DSL, Satellite, dial-up, none of that matters. The problem is the same for any TCP/IP service.
--
Norman
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum |
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bbiandov
join:2001-02-09
San Francisco, CA | reply to bbiandov
Yep, I'm a dork. Thanks. I see your point and it is a good one! |
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