Messages in this thread | | | Subject | Re: Linux iSCSI Initiator, OpenSource (fwd) (Re: Gauntlet Set NOW!) | From | Valdis.Kletnieks@vt ... | Date | Tue, 07 Jan 2003 00:38:18 -0500 |
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On Mon, 06 Jan 2003 22:20:46 CST, Oliver Xymoron said:
> What was the underlying error rate and distribution you assumed? I > figure if it were high enough to get to your 1%, you'd have such high > retry rates (and resulting throughput loss) that the operator would > notice his LAN was broken weeks before said transfer completed.
The average ISP wouldn't notice things were broken unless enough magic smoke escaped to cause a Halon dump.
Consider as evidence the following NANOG presentation:
http://www.nanog.org/mtg-0210/wessels.html
Some *98* percent of all queries at one of the root nameservers over a 24-hour period were broken in some way. And there wasn't even a DDoS in progress at the time...
Also, I think Andrew was computing the chances that *SOME* packet in the 100T would be mangled in an undetected fashion, so 99% of the time all 100T would be OK, but 1% of the time there was some subtle block mangling some dozens of terabytes into the transfer. Given that the TCP slow-start code is currently busticated for gigabit and higher (it takes *hours* without a packet drop to get the window open *all* the way - there's IETF drafts in process about this), it's quite possible that you'd not notice packet drops due to error among all the congestion drops kicking the window size down..... -- Valdis Kletnieks Computer Systems Senior Engineer Virginia Tech
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