- NANOG - lists.nanog.org

Re: Hi speed trading - hi speed monitoring
by Hank Nussbacher 16 Feb '12

16 Feb '12

At 13:49 16/02/2012 +0000, Jethro R Binks wrote: >On Thu, 16 Feb 2012, Hank Nussbacher wrote: > > > Nanosecond Trading Could Make Markets Go Haywire > > http://www.wired.com/wiredscience/2012/02/high-speed-trading/ > > > > "Below the 950-millisecond level, where computerized trading occurs so > > quickly that human traders can't even react, no fewer than 18,520 > > crashes and spikes occurred." > > > > Anyone who has managed a network knows that when you look at your > > MRTG/Cacti graphs at 5min, 10min ,15min intervals - all looks well. > > Start looking at 1sec intervals and you will see spikes that hit 100% of > > capacity - even on networks running at 25% average utilization. > > > > I guess trading and networking do have many unseen similarities. > >Tieing the two together, this post shows how a lot of 'conventional' >network thinking needs to be turned on its head when it comes to networks >for trading floors: > >http://www.fragmentationneeded.net/2011/12/pricing-and-trading-networks-dow… Great article! Thanks for sharing, Hank >Jethro. > >. . . . . . . . . . . . . . . . . . . . . . . . . >Jethro R Binks, Network Manager, >Information Services Directorate, University Of Strathclyde, Glasgow, UK > >The University of Strathclyde is a charitable body, registered in >Scotland, number SC015263.

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802.11 MAC Point Coordination Function
by Jeremy 16 Feb '12

16 Feb '12

Hi All, I'm doing some research on 802.11 quality of service, congestion control, etc. I'm trying to find some information on the Point Coordination Function, a polling based access control method, but I'm having a hard time finding much in the way of vendor support. I have access to some cisco 1242's, 1140's and 1252's and I've been searching the Cisco's site and can't find a real answer on whether or not it's supported let alone how to configure it. Does anyone have any experience with this? Does Cisco have some special name for it aside from PCF? Any help would be appreciated! Thanks, Jeremy

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Wireless Recommendations
by Jim Gonzalez 16 Feb '12

16 Feb '12

Hi, I am looking for a Wireless bridge or Router that will support 600 wireless clients concurrently (mostly cell phones). I need it for a proof of concept. Thanks in advance Jim

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and now for something completely different
by bmanning＠vacation.karoshi.com 16 Feb '12

16 Feb '12

Control of ground-state pluripotency by allelic regulation of Nanog Nature advance online publication 12 February 2012. doi:10.1038/nature10807 Authors: Yusuke Miyanari & Maria-Elena Torres-Padilla Pluripotency is established through genome-wide reprogramming during mammalian pre-implantation development, resulting in the formation of the naive epiblast. Reprogramming involves both the resetting of epigenetic marks and the activation of pluripotent-cell-specific genes such as Nanog and Oct4 (also known as Pou5f1). The tight regulation of these genes is crucial for reprogramming, but the mechanisms that regulate their expression in vivo have not been uncovered. Here we show that Nanog—but not Oct4—is monoallelically expressed in early pre-implantation embryos. Nanog then undergoes a progressive switch to biallelic expression during the transition towards ground-state pluripotency in the naive epiblast of the late blastocyst. Embryonic stem (ES) cells grown in leukaemia inhibitory factor (LIF) and serum express Nanog mainly monoallelically and show asynchronous replication of the Nanog locus, a feature of monoallelically expressed genes, but ES cells activate both alleles when cultured under 2i conditions, which mimic the pluripotent ground state in vitro. Live-cell imaging with reporter ES cells confirmed the allelic expression of Nanog and revealed allelic switching. The allelic expression of Nanog is regulated through the fibroblast growth factor–extracellular signal-regulated kinase signalling pathway, and it is accompanied by chromatin changes at the proximal promoter but occurs independently of DNA methylation. Nanog-heterozygous blastocysts have fewer inner-cell-mass derivatives and delayed primitive endoderm formation, indicating a role for the biallelic expression of Nanog in the timely maturation of the inner cell mass into a fully reprogrammed pluripotent epiblast. We suggest that the tight regulation of Nanog dose at the chromosome level is necessary for the acquisition of ground-state pluripotency during development. Our data highlight an unexpected role for allelic expression in controlling the dose of pluripotency factors in vivo, adding an extra level to the regulation of reprogramming.

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Models of DNS traffic and caches
by John Levine 15 Feb '12

15 Feb '12

Are there any analytic or simulation models of DNS traffic and caches? Say I have a DNS cache that handles two different kinds of traffic, DNSBL lookups that are almost never reused, and web page lookups that are frequently reused. Is there a model that will predict whether partitioning the cache would be a good idea, or capping TTL on the DNSBLs, or other sorts of tricks? Pointers are fine. TIA. R's, John -- Regards, John Levine, johnl(a)iecc.com, Primary Perpetrator of "The Internet for Dummies", Please consider the environment before reading this e-mail. http://jl.ly

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Re: IP Transit with netflow report?
by ali baba 15 Feb '12

15 Feb '12

Hi Everyone, Hope someone can help me out.. I have some IP Transit links with one of the Tier1s and I need to know the source<>destination of traffic passing though.. My provider gives me a straight "NO, we can provide this" and I am wondering if anyone knows of any providers who gives out netflow report? Cheers, AB

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Re: Dear RIPE: Please don't encourage phishing
by Brandon Butterworth 15 Feb '12

15 Feb '12

> So it's necessary to throw the baby out with the bathwater, and tell them > never to click on a link... That baby was ugly anyway brandon

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Sonicwall 3500/netflow
by Jay Ashworth 14 Feb '12

14 Feb '12

This will be my first time in Sonicwall territory. I'm assuming this thing will (effectively) *be* my edge router; does it support netflow, as has been being discussed in the recent thread? I'm likely going to have 100M from L3, with FiOS/150 and Roadrunner/50 for backup/load bal; I don't think this will be a BGP application. :-) Cheers, -- jra -- Jay R. Ashworth Baylink jra(a)baylink.com Designer The Things I Think RFC 2100 Ashworth & Associates http://baylink.pitas.com 2000 Land Rover DII St Petersburg FL USA http://photo.imageinc.us +1 727 647 1274

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Clued contact at Brighthouse
by James Milko 14 Feb '12

14 Feb '12

Brighthouse seems to be announcing one of our prefixes. Does anyone have a contact for them that doesn't end up in residential support? Thanks, James Milko Senior Network Engineer www.inetwork.com 4001 Weston Parkway Cary, NC 27513 inetwork is a division of Bandwidth

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Does anyone know anything about intelishift.com?
by Landon Stewart 14 Feb '12

14 Feb '12

Does anyone know if intelishift.com has a reputation that is good or bad? I have never heard of them before but need to know some more about them. If you have anything to share please let me know off-list. We are seeing some unscrupulous behaviour from them regarding marketing and spam. --- Landon Stewart <lstewart(a)superb.net <mailto"LStewart(a)Superb.Net>> Manager of Systems and Engineering Superb Internet Corp - 888-354-6128 x 4199 Web hosting and more "Ahead of the Rest": www.superb.net

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