Date: Sun, 15 Oct 2000 02:01:29 -1000 (HST) From: Vincent Poy <vince@oahu.WURLDLINK.NET> To: Len Conrad <lconrad@Go2France.com> Cc: freebsd-questions@FreeBSD.ORG Subject: Re: Best DSL Router? Message-ID: <Pine.BSF.4.21.0010150155500.1344-100000@oahu.WURLDLINK.NET> In-Reply-To: <5.0.0.25.0.20001015134404.06dc9710@mail.Go2France.com>
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On Sun, 15 Oct 2000, Len Conrad wrote: > >I'm just wondering if FreeBSD as a router has any traffic shaping > >features > > dummynet or etinc bw-mgr I completely forgot about etinc's bw-mgr. I never really knew what dummynet was used for until now. > >since most ADSL is faster downstream than upstream and when one > >is uploading tradionally, it will choke the download speeds because the > >uploading would take all the bandwidth for the upload pipe that it can't > >get the acknowledgement packets out for the downloaded data at the same > >time. > > ??? ADSL is full duplex. up channel does not rob/share bandwidth > from down channel. You should be able to get 128 up while getting 512 > down, or whatever your signalling rates are. ADSL is not full duplex. ADSL is Assymetrical DSL. SDSL is Full Duplex. With PacBell ADSL, the upstream 128k is shared with the downstream 1.5Mbps on a standard phone line connected to a Alcatel DSLAM. If one was downloading only, one does get 150kbytes/sec which 193kbytes/sec is the max for a 1.544Mbps connection. If you were uploading, it would be 13kbytes/sec up and the downloads would slow down to 30kbytes/sec. This is only a problem if you do both simultaneously since it's a known issue as discussed on the ba.internet newsgroup because of the way TCP/IP is designed and what happens is the uploads will take up the entire 128kbps so there is no room for the Acknowledgement packets to be sent back for the received packets. That's one reason why I mentioned traffic shaping as that seems to be the only solution. > Paradyne MVL does share 768 kbits/sec between the two channels but > that is afaik unique to MVL, which isn't typical xDSL. Yes, but are you uploading and downloading at the same time. That's a different issue altogether. Cheers, Vince - vince@WURLDLINK.NET - Vice President ________ __ ____ Unix Networking Operations - FreeBSD-Real Unix for Free / / / / | / |[__ ] WurldLink Corporation / / / / | / | __] ] San Francisco - Honolulu - Hong Kong / / / / / |/ / | __] ] HongKong Stars/Gravis UltraSound Mailing Lists Admin /_/_/_/_/|___/|_|[____] Almighty1@IRC - oahu.DAL.NET Hawaii's DALnet IRC Network Server Admin To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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