I hear the Matcalfe has been spending some time recently at the MIT Julia lab working on climate issues.
Bob Metcalfe wins Turing Award
171–180 of 238 posts
Re: Bob Metcalfe wins Turing Award
#172> "Metcalfe insists on calling Wi-Fi by its original name, Wireless Ethernet, for old times’ sake."
Okay, besides all his contributions, I've decided this guy is my favorite for that alone. Imagine if he was your (great?) uncle and you're on a family vacation together. "What's the Wi-Fi password here, Bob?"
Bob: "What's the what now?"
You: "Excuse me. What's the Wireless Ethernet password?"
Bob: "Oh, it's HotelGuest2023"
Re: Bob Metcalfe wins Turing Award
#173Earlier quoted context omitted.
2.5G or even 10G is not that much more expensive and companies making consumer electronics sell it as a considerable premium for what is essentially the same cost difference as making a 8gb vs 16 gb flash drive. Of course, regular internet users don't need more than 2.5G (and couldn't use it in most of the world due to ISP monopolies) so anything faster than gigabit is a target for segmentation.
The market at work. There is just no real demand for anything beyond 1G. The HN crowd is not representative of what would be needed to drive the price tags down on 2.5G stuff.
If you have a gigabit internet connection, then most of the value of 10G comes from data sharing within the intranet, which just never caught on outside of hobbyists. And a 1G switch can still handle a lot of that, You don’t even need 10G for LAN parties, and whether backups can go faster depends on the storage speed and whether you actually care. Background backups hide a lot of sins.
I’m hoping a swing back to on-prem servers will justify higher throughput, but that still may not be the case. You need something big to get people to upgrade aging infrastructure. What would be enough to get people to pay for new cable runs? 20Gb? 40?
Re: Bob Metcalfe wins Turing Award
#174Bob has been an active member of the Austin startup community for 10+ years and I've talked with him many times. As a EE, it was cool meeting him the first time and once I'd chatted with him a few times, I finally asked the question I'd been dying to ask: How'd you come up with "Metcalfe's Law"? Metcalfe's Law states the value of a network is proportional to the square of the number of devices of the system. When I f…
HN comment of the year winner right here! Makes you wonder how many other laws are built on nothing. If there's one thing I leaned doing a Ph.D. is if you dig deep enough, you find many foundational laws of nature rely on some necessary assumption that, if proven incorrect, would topple the whole thing
Do you know of any in particular?
Re: Bob Metcalfe wins Turing Award
#175Earlier quoted context omitted.
This part's not in the book: Gordon Peterson, the architect of ARCNet, was a major source for me. He talked to Bob back in the day. Gordon's still bitter about it, and will gladly tell you why Ethernet is inferior.
Well.. I still want to read the book. I'm a sucker for a well crafted story about old hardware from the days when technology gods walked the earth. I'm sure Ethernet's market domination is because the spec wasn't owned by a single company, and nothing to do with it's technical merits. After IBM's SNA, people seemed paranoid of a networking spec being owned by a single company. Do you know if Datapoint thought about t…
on DataPoint: my hero (sort of) Matt Feingold spends a summer internship at DataPoint. As far as he (and I) could tell, people still thought in terms of "account control" back then.
There's actually a book on DataPoint (and almost every other company from way back when). I read them so you don't have to :)
Re: Bob Metcalfe wins Turing Award
#176> "Metcalfe insists on calling Wi-Fi by its original name, Wireless Ethernet, for old times’ sake." Okay, besides all his contributions, I've decided this guy is my favorite for that alone. Imagine if he was your (great?) uncle and you're on a family vacation together. "What's the Wi-Fi password here, Bob?" Bob: "What's the what now?" You: "Excuse me. What's the Wireless Ethernet password?" Bob: "Oh, it's HotelGuest2…
Okay that's funny
Re: Bob Metcalfe wins Turing Award
#177Earlier quoted context omitted.
I remember trying to get NICs to work in Linux and the best advice was usually “just try the 3c509 driver”.
I remember when I bought my first fast ethernet card, there was some Linux HOWTO that discussed various ethernet NIC's, and crucially, their Linux drivers in excruciating detail. And the takeaway was that if you had a choice, pick either 3com 5xx(?) or Intel card. The 3com card was slightly cheaper at the local computer shop, so that's what I ended up with (595 Vortex, maybe?).
Yeah, I had gold-plated 100Mb 3Com cards and they were the best. (something-905-series?) With full-duplex, hardware offloading, good drivers. I still have one lying somewhere. )
Re: Bob Metcalfe wins Turing Award
#178Earlier quoted context omitted.
You don't need an interrupt per packet, at least not with sensible NICs and OSes. Something like 10k interrupts per second is good enough, pick up a bunch of packets on each interrupt; you do lose out slightly on latency, but gain a lot of throughput. Look up 'interrupt moderation', it's not new, and most cards should support it. Professionlly, I ran dual xeon 2690v1 or v2 to 9Gbps for https download on FreeBSD; http…
Interrupt moderation only gives a modest improvement, as can be seen from the benchmarking done by Intel. Intel would also not have gone through the effort to develop DPDK if all you had to do to achieve linerate performance would be to enable interrupt moderation. Furthermore, quoting Gbps numbers is beside the point when the limiting factor is packets per second. It is trivial to improve Gbps numbers simply by usin…
I'm quoting bulk transfer, with 1500 MTU. I could run jumbo packets for my internal network test and probably get better numbers, but jumbo packets are hard. When I was quoting https download on public internet, that pretty much means MTU 1500 as well, but was definitely the case.
If you're sending smaller packets, sure, that's harder. I guess that's a big deal if you're a DNS server, or voip (audio only); but if you're doing any sort of bulk transfer, you're getting large enough packets.
> Intel would also not have gone through the effort to develop DPDK if all you had to do to achieve linerate performance would be to enable interrupt moderation.
DPDK has uses, sure. But you don't need it for 10G on decent hardware, which includes 7 year old server chips, if you're just doing bulk transfer.
Re: Bob Metcalfe wins Turing Award
#179Bob has been an active member of the Austin startup community for 10+ years and I've talked with him many times. As a EE, it was cool meeting him the first time and once I'd chatted with him a few times, I finally asked the question I'd been dying to ask: How'd you come up with "Metcalfe's Law"? Metcalfe's Law states the value of a network is proportional to the square of the number of devices of the system. When I f…
Not only did he make it up, but it is false! Multiple lines of evidence point to a O(n log(n)) law instead.
https://www-users.cse.umn.edu/~odlyzko/doc/metcalfe.pdf has the details.
Re: Bob Metcalfe wins Turing Award
#180Earlier quoted context omitted.
I respect Metcalfe a lot, but halfway through undergraduate discrete math it was pretty obvious to most people in the class even before seeing a formal proof that a fully connected graph has O(n^2) edges. I just figured that people wowed by "Metcalfe's Law" were business types who didn't any formal theory into computing.
Metcalfe's law is about network impact or value, not about connections.
It counts connections and uses them as an estimate of value.
However not all connections are equally valuable. And therefore the "law" is incorrect. An estimate in far better agreement with the data is O(n log(n)), and you can find multiple lines of reasoning arriving at that in https://www-users.cse.umn.edu/~odlyzko/doc/metcalfe.pdf.