Tuesday, June 30, 2009

better than zero-copy stacks

conundrum - can you do better than a zero-copy stack?

far as i recall, some folks at Sun Microsystems did the first unix with zero copy
from user space to/from network device way way back (prob. 92?) so that was as good as it gets in some sense....or is it? can you get a packet from the net in less than no time? I think you can in the sense that you could wake up the application before all the packet had finished dma-ing (or for a non blocking read/write application, you could do the copy on write thing 1 bit ahead rather than the whole packet) - of course, you'd need some insanely fine grain lock on the packet buffer somehow (or some fine grain virtual memory hack) which will be Rather Expensive(TM) in Real Life...

Friday, June 19, 2009

quantum networking...

I just got back from madrid where we had a nice dinner in Real Madrid's home stadium restuarant. the event was IMDEA's seminar n qunatum networking and had some seriously interesting talks from

Chip Elliott, BBN Technologies, USA
has a real operational QKD net in Cambridge Mass

Matthieu Legr?, id Quantique, Switzerland
works for a company that sell working QKD kit

Michele Mosca, Inst. of Quantum Computing, Canada
runs this institute in Waterloo which does the whole thing (incl QC algorithmics)

Emina Soljanin, Bell Labs, USA
very clear theorist with clean models of things like quantum multicast

Paolo Villoresi, Univ. of Padova, Italy
QKD over satellite and other free space (i.e. non photonic/fiber) based channels!

i had 4 bad ideas during the meeting
1. have a classical resource model of qunatum resources for the classically challenged
2. QKD satellelites could provide eye in the sky secure control plane
3. QZKP and other interesting zero knowledge or shared secret stuff, homomrphic hashes, quantum watermarks)
4. what's the Qbit rate for a multihop free space qunatum channel?

my proposal is to get the physicists to do this under some bogo-banner (e.g. Quntum Grid)

Monday, June 15, 2009

isps complaints about content companies

so here's th thing
BT, (for example) complain that the bbc's iplayer (for example) causes too much traffic.
well, huhn - now I susbscribe to the internet at a given data rate because that is what is advertised - note this is a _download_ rate - I am already getting a massively erduced uplink speed to prevent me messign up the net as a small customer, and that is fine (and partly due to technology and physics limitations of ADSL on copper).

but when they sold me a service, they should have thought "oh, maybe he'll actually use it" - note I have a solid 8Mbps...

and when the BBC connect a large scale data center to the net (at some large scale price)
maybe the service provider should think "hmm, wonder why they're doing that" and think about who they are (oh, the bbc - maybe they want to let people download programmes later)

so when they service provider complains about the content provider "causing too much traffic", recall AT& complaining about google "causing load" and wanting a slice of the action

whaty is really going on is that company A failed to realise company B was going to be a success, and is now upset it didn't and is trying to remove neutrality as a threat (stick) to get a part of company B's profit. Nevermind that there was nothing whatsoever except lack of imagination stopping company A being in the business company B provided (oh, ok, so in BT's case, there was a long running rule about being a TV company....however this didn't stop them making money out of selling capacity to TV broadcast companies, and now, thanks to Ofcomm, is going away anyhow).

No, sorry, this is getting silly - nonetheleast because they "blame" is the wrong direction - blaming the BBC because the BBC's customers use BT's customers to use BT's network is surreal. You sell some folks a network, (and get a monthly fee, AND a lot of them upgrade as fast as they can pay more to get the upgrade) then complain when they use the network. Doh. what business did you want to be in then, is it?

(BT is a bad example, I admit due to the old no-TV rule) - so add your own.

Now look at Virgin's new "all you can eat" music subscription service proposal , and big stick if you do anything bad (they disconnect you) - this sounds like dubious practice to me...

Thursday, June 11, 2009

a week in cambridge

this week has been bonkers - we had a great talk on monday by Fabio Bustamante about his use of crowdsourcing in bittorrent clients to measure the internet
then we had this stochastic nets workshop which Richard Gibbens organised which was fantastic, with loads of great talks on resource pooling, P2P systems and so on, then we had this workshop on pricing an auctions which Peter Key organised with some great talks on mechanism design and social networks, and now we have this biowire 2009 workshop which has some superb talks on the natural world and its "network" algorithms, and there was a really great semianr by Andrew Birrell on the history of concurrency!

enough for a whole year

Monday, June 08, 2009

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