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I used to work for Fulcrum Microsystems. Super fun. Your summary of the market around that is great. Thanks! I had not thought about them in a while. The techn

I used to work for Fulcrum Microsystems. Super fun. Your summary of the market around that is great. Thanks! I had not thought about them in a while. The technology involved in enabling 64 octet frames to be shoved around in 300ns is fascinating. The software control of these systems was just as fascinating. These chips had a high level of programmability in the frame handler. How to use that programmability was an open question when I left Fulcrum.

myrandomcomment 12y ago
The thing that make the Fulcrum stuff so cool at the time was the chips being asynchronous, which is very very strange. Fulcurm had to built their own tools to validate the layout etc. Amazingly complex. Most people do not realize how amazingly complex this ASIC stuff is and how hard it is to get right without major bugs. One very interesting bug, but one that did not really matter, was handing 1G at line rate. For those that do not know a bit of a background. So you have a 10G chip that connects to a PHY chip. http://en.wikipedia.org/wiki/SerDes http://en.wikipedia.org/wiki/SerDes There are 4 x 3.25G lanes to the PHY. Now lets say you want to put a 1G SFP in that port. Well the path uses only one of the 3.25G lanes, not all 4. All the of logic and timing is really built around the packets going over the 4 links. So anyway, if you ran a test at 100% line rate with a 1G optic there would be drops if your packet size was not divisible by 4. The stand packets sizes that are commonly used for RFC2544 testing are 64,128,256,512,1024,1280,1518. So all the sizes work expect for 1518. You could do 10G at line rate @ 1518 packet size but not 1G! It is very important for everyone to understand that this only matters in lab testing and has ZERO impact in a real world environment. If you changed the IFG on the link it would run at line rate. http://en.wikipedia.org/wiki/Interpacket_gap http://en.wikipedia.org/wiki/Interpacket_gap The Fulcurm chips were amazing. I very much enjoyed using them.
sargun 12y ago
What happened to Fulcrum? I know Intel bought them. The FM6000 is still their top of the line chip. When can I get a new switch that's competitive to T2, with FlexPipe?
- wmf 12y ago
  There are tidbits of info about the FM10000 going around but I haven't seen speeds and feeds. It seems to integrate the NICs into the switch; I'm not sure what the point of that is.

myrandomcomment 12y ago

The thing that make the Fulcrum stuff so cool at the time was the chips being asynchronous, which is very very strange. Fulcurm had to built their own tools to validate the layout etc. Amazingly complex. Most people do not realize how amazingly complex this ASIC stuff is and how hard it is to get right without major bugs. One very interesting bug, but one that did not really matter, was handing 1G at line rate. For those that do not know a bit of a background. So you have a 10G chip that connects to a PHY chip. http://en.wikipedia.org/wiki/SerDes http://en.wikipedia.org/wiki/SerDes There are 4 x 3.25G lanes to the PHY. Now lets say you want to put a 1G SFP in that port. Well the path uses only one of the 3.25G lanes, not all 4. All the of logic and timing is really built around the packets going over the 4 links. So anyway, if you ran a test at 100% line rate with a 1G optic there would be drops if your packet size was not divisible by 4. The stand packets sizes that are commonly used for RFC2544 testing are 64,128,256,512,1024,1280,1518. So all the sizes work expect for 1518. You could do 10G at line rate @ 1518 packet size but not 1G! It is very important for everyone to understand that this only matters in lab testing and has ZERO impact in a real world environment. If you changed the IFG on the link it would run at line rate. http://en.wikipedia.org/wiki/Interpacket_gap http://en.wikipedia.org/wiki/Interpacket_gap The Fulcurm chips were amazing. I very much enjoyed using them.

sargun 12y ago

What happened to Fulcrum? I know Intel bought them. The FM6000 is still their top of the line chip. When can I get a new switch that's competitive to T2, with FlexPipe?

wmf 12y ago
There are tidbits of info about the FM10000 going around but I haven't seen speeds and feeds. It seems to integrate the NICs into the switch; I'm not sure what the point of that is.