Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Bob Metcalfe wins Turing Award

amturing.acm.org

Post reply on HN
Print view View original

111–120 of 238 posts

Re: Bob Metcalfe wins Turing Award

#111

Post by throw0101b »

RF_Savage wrote: post #88
lunfard000 wrote: post #16

Earlier quoted context omitted.

Sure, years ago. But today Ethernet is just as scammy as everyone else, we've been stuck at 1 Gbps on consumer grade hardware for more than 15 years. There are claims (unverified ofc) about their executives boasting about their stupid margins. 1 Gb switch is like 10-20 euros meanwhile 2.5 Gbps is like over 100...

2.5Gb is downshifted 10Gb with the same line coding, just with 1/4 the symbol rate. This means that it inherits all the complexities of 10GbE, while tolerating cheaper connectors and cables. 10GbE uses DSQ128 PAM-16 at 800Msym/s. 2.5G just does quarter-rate at 200Msym/s. 1000BaseT uses trellis coded PAM-5, a significantly less complex modulation. When one factors in the complexity of the line code and all equalisatio…

> tolerating cheaper connectors and cables

I always find the graphic below handy for telling which Cat cable can handle which Gig speed:

* https://en.wikipedia.org/wiki/Ethernet_over_twisted_pair#Var...

Re: Bob Metcalfe wins Turing Award

#112

Post by throw0101b »

dale_glass wrote: post #96
lunfard000 wrote: post #16

Earlier quoted context omitted.

Sure, years ago. But today Ethernet is just as scammy as everyone else, we've been stuck at 1 Gbps on consumer grade hardware for more than 15 years. There are claims (unverified ofc) about their executives boasting about their stupid margins. 1 Gb switch is like 10-20 euros meanwhile 2.5 Gbps is like over 100...

You can have 10G with eg, Mikrotik at a reasonable price. One problem with it is that the copper tech is just power hungry. It may actually make sense to go with fiber, especially if you might want even more later (100G actually can be had at non-insane prices!) Another problem is that it's CPU intensive. It's actually not that hard to run into situations where quite modern hardware can't actually handle the load of…

> Another problem is that it's CPU intensive.

Are there 10GigE cards that do not do things like IP/TCP offloading at this point?

Offloading dates back to (at least) 2005:

* https://www.chelsio.com/independent-research-shows-10g-ether...

* https://www.networkworld.com/article/2312690/tcp-offload-lif...

Re: Bob Metcalfe wins Turing Award

#113

Post by rasz »

lambda_dn wrote: post #65

Wifi/5G guys next? Much more important invention in my opinion

Wifi would have to go to Steve Jobs :-) Lucent was sitting on 802.11 (WaveLAN) for ten years selling super expensive products targeting niche markets and it took Apple to move things forward. More in “Oral History of Arthur “Art” Astrin”, wifi pioneer: https://youtu.be/Tj5NNxVwNwQ

Re: Bob Metcalfe wins Turing Award

#114

Post by jabl »

chasd00 wrote: post #51
caseysoftware wrote: post #24

Bob 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…

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?).

Re: Bob Metcalfe wins Turing Award

#115

Post by jpalomaki »

In this Infoworld column back in 1995 Bob predicted Internet would collapse in 1996 due to security breaches, capacity overloads, and demand for video online. He also promised to eat the article if this did not happen. And kept his promise.

https://1995blog.com/2015/12/03/prediction-of-the-year-1995-...

Re: Bob Metcalfe wins Turing Award

#116

Post by williamDafoe »

This just shows what a huge joke the Turing Award process is! He should have gotten this award by 2000 or never at all! But the committee was too busy giving out awards for writing sexy sounding papers about stoplight verification and zero knowledge proofs to honor someone who disrupteded the whole field!

Re: Bob Metcalfe wins Turing Award

#117

Post by dale_glass »

throw0101b wrote: post #112
dale_glass wrote: post #96

Earlier quoted context omitted.

You can have 10G with eg, Mikrotik at a reasonable price. One problem with it is that the copper tech is just power hungry. It may actually make sense to go with fiber, especially if you might want even more later (100G actually can be had at non-insane prices!) Another problem is that it's CPU intensive. It's actually not that hard to run into situations where quite modern hardware can't actually handle the load of…

> Another problem is that it's CPU intensive. Are there 10GigE cards that do not do things like IP/TCP offloading at this point? Offloading dates back to (at least) 2005: * https://www.chelsio.com/independent-research-shows-10g-ether... * https://www.networkworld.com/article/2312690/tcp-offload-lif...

You can go fast if you don't do anything fancy with the interface.

If you say, want bridged networking for your VMs and add your 10G interface to virbr0, poof, a good chunk of your acceleration vanishes right there.

Routing and firewalling also cost you a lot.

There are ways to deal with this with eg, virtual functions, but the point is that even on modern hardware, 10G can be no longer a foolproof thing to have working at full capacity. You may need to actually do a fair amount of tweaking to have things perform well.

Re: Bob Metcalfe wins Turing Award

#118

Post by williamDafoe »

throw0101b wrote: post #107

Somewhat related: The choice of 48 bits for the hardware/station address seems to have been a pretty good choice: it's been 40+ years and we still have no run out. I'm curious to know if anyone has done the math on when Ethernet address exhaustion will occur. While the Ethernet frame has been tweaked with over the decades, addressing has been steady. Curious to know if any transition will ever been needed and how wou…

It was Xerox & Yogen Dalal's choice, not Bob's choice! Xerox blew it with 8-bit station addresses in PuP (PARC Universal Protocol) and wanted to give each station a UID to break ties in database transactions, hence the 48-bits. XNS actually had 3-byte station and 3-byte network size to fit in 6-byte MAC addresses! Metcalfe is not a software engineer and wouldn't have these insights ...

Re: Bob Metcalfe wins Turing Award

#119

Post by oaiey »

jacquesm wrote: post #4

Well deserved. I remember dealing with a whole raft of other networking technologies and Ethernet stood head-and-shoulders above anything else available at the time. One thing that is not well appreciated today is how power efficient Ethernet was, even on launch in the coax era. Other network technologies (Token Ring as embodied by IBMs network cards, for instance) consumed power like there was no tomorrow. Leading t…

WiFi is not the competition ;) It is the brother in arms ;)

Re: Bob Metcalfe wins Turing Award

#120

Post by iptrans »

throw0101b wrote: post #112
dale_glass wrote: post #96

Earlier quoted context omitted.

You can have 10G with eg, Mikrotik at a reasonable price. One problem with it is that the copper tech is just power hungry. It may actually make sense to go with fiber, especially if you might want even more later (100G actually can be had at non-insane prices!) Another problem is that it's CPU intensive. It's actually not that hard to run into situations where quite modern hardware can't actually handle the load of…

> Another problem is that it's CPU intensive. Are there 10GigE cards that do not do things like IP/TCP offloading at this point? Offloading dates back to (at least) 2005: * https://www.chelsio.com/independent-research-shows-10g-ether... * https://www.networkworld.com/article/2312690/tcp-offload-lif...

TCP/IP offload isn’t the issue.

The core problem is that the Linux kernel uses interrupts for handling packets. This limits Linux networking performance in terms of packets per second. The limit is about a million packets per second per core.

For reference 10GE is about 16 million packets per second at line rate using small packets.

This is why you have to use kernel bypass software in user space to get linerate performance above 10G in Linux.

Popular software for this use case utilize DPDK, XDP or VPP.

Post reply on HN