RE: Pseudorandom Flow Labels
"Hemant Singh (shemant)" <shemant@cisco.com> Wed, 06 April 2011 01:13 UTC
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Subject: RE: Pseudorandom Flow Labels
Date: Tue, 05 Apr 2011 20:15:18 -0500
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Thread-Topic: Pseudorandom Flow Labels
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From: "Hemant Singh (shemant)" <shemant@cisco.com>
To: james woodyatt <jhw@apple.com>, ipv6@ietf.org
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Cc: Thomas Narten <narten@us.ibm.com>
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Snipped from RFC 4193 is this text. "pseudo-randomly allocated global ID". If pseudo-random was accepted in this RFC, why are we discussing pseudo-random again? One reason is acceptable to me that over the years we learn to be more precise or more audience read the documents and thus more folks can ask for a better choice for a term. I agree with Thomas that we can pick a term but then the term has to be defined clearly. Here is some text from RFC 4193 one could use. This way we avoid the IETF specifying what pseudo-random algorithm to use but still get a as precise as possible definition that has been accepted in other RFCs such as RFC 4193. [Locally assigned Global IDs MUST be generated with a pseudo-random algorithm consistent with [RANDOM].] Hemant -----Original Message----- From: ipv6-bounces@ietf.org [mailto:ipv6-bounces@ietf.org] On Behalf Of james woodyatt Sent: Tuesday, April 05, 2011 6:49 PM To: Thomas Narten Cc: 6MAN Working Group Subject: Re: Pseudorandom Flow Labels On Apr 5, 2011, at 14:48 , Thomas Narten wrote: > [I wrote:] >> >> I share your concern. Would replacing "pseudo-random" with "low discrepancy" address your concerns? > > Replacing the term with another would be fine. That said, the real issue is we need to define what we mean by whatever term we use. Discrepancy is a measure of the deviation of a point set from a uniform distribution. Or, so Wolfram MathWorld tells me. <http://mathworld.wolfram.com/Discrepancy.html> A low discrepancy sequence would be one that has *approximately* uniform distribution [though, not necessarily *exactly* uniform], which is what seems to be the object of the game here. There are many excellent well-known low discrepancy sequences to choose from, and I'm not sure IETF needs to specify a standard one, but it's possible one could be found if we really tried hard. If you want to get hideously pedantic, you could specify a maximum discrepancy; I'm sure Timothy Winters and his crew would just melt if you did that. Note: another term for "low discrepancy" is "quasi-random" but I'm not sure we want to go there. -- james woodyatt <jhw@apple.com> member of technical staff, core os networking -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
- Re: Pseudorandom Flow Labels Thomas Narten
- Pseudorandom Flow Labels Shane Amante
- Re: Pseudorandom Flow Labels Thomas Narten
- Re: Pseudorandom Flow Labels Shane Amante
- Re: Pseudorandom Flow Labels james woodyatt
- Re: Pseudorandom Flow Labels Thomas Narten
- Re: Pseudorandom Flow Labels james woodyatt
- Re: Pseudorandom Flow Labels Thomas Narten
- Re: Pseudorandom Flow Labels John Leslie
- Re: Pseudorandom Flow Labels james woodyatt
- RE: Pseudorandom Flow Labels Hemant Singh (shemant)
- RE: Pseudorandom Flow Labels Hemant Singh (shemant)
- Re: Pseudorandom Flow Labels Brian E Carpenter
- Re: Pseudorandom Flow Labels Thomas Narten
- Re: Pseudorandom Flow Labels Fernando Gont
- Re: Pseudorandom Flow Labels Fernando Gont
- Re: Pseudorandom Flow Labels Fernando Gont
- Re: Pseudorandom Flow Labels Fernando Gont
- Re: Pseudorandom Flow Labels Fernando Gont
- Re: Pseudorandom Flow Labels John Leslie
- Re: Pseudorandom Flow Labels Fernando Gont
- Re: Pseudorandom Flow Labels Shane Amante
- Re: Pseudorandom Flow Labels Fernando Gont
- Re: Pseudorandom Flow Labels Brian E Carpenter
- Re: Pseudorandom Flow Labels Fernando Gont
- Re: Pseudorandom Flow Labels John Leslie
- Re: Pseudorandom Flow Labels Fernando Gont