Date: Tue, 8 May 2007 21:22:15 +1000 From: Peter Jeremy <peterjeremy@optushome.com.au> To: suvashrestha@wlink.com.np Cc: freebsd-net@freebsd.org Subject: Re: bridge query Message-ID: <20070508112215.GF838@turion.vk2pj.dyndns.org> In-Reply-To: <SFkMdvkN.1178616027.1227980.suvashrestha@wlink.com.np> References: <mailman.6487.1178613103.783.freebsd-net@freebsd.org> <SFkMdvkN.1178616027.1227980.suvashrestha@wlink.com.np>
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--Y5rl02BVI9TCfPar Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 2007-May-08 14:20:27 +0500, suvashrestha@wlink.com.np wrote: >i am using freebox 5.4 as a bridge using dummynet. =2E.. >When I add delay of 250ms and plr of 0.05 (5%), the packet transfer falls >to 80Kbit/s. How are you measuring packet transfer (single TCP socket, multiple TCP sockets or UDP) and what were you expecting? For a TCP connection, the window size needs to be able to handle at least 1 RTT (0.5 second in this case) of data. This translates to a total of 5Mb (~640KB) outstanding data to get 10Mbps throughput. With only a single cnnection, you would need a 640KB window size - which is far larger (an order of magnitude or so) than typical. TCP is also designed to work on a mostly lossless link. I am not sure how much a 5% packet loss will affect it but I would expect it to be significant. I'm not sure how to optimise throughput in this situation. --=20 Peter Jeremy --Y5rl02BVI9TCfPar Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (FreeBSD) iD8DBQFGQF1n/opHv/APuIcRAvewAJsHDb324nYSB4HNqgpPJ8t2lk2YRwCglPhf gMDoyTTeHt6/jPeHtDb7CSs= =Zmpu -----END PGP SIGNATURE----- --Y5rl02BVI9TCfPar--
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