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Can You Purchase Switch Hardware Without an OS?

Posted by ryuzaki0 on from the barebones-hardware dept.

dhahn asks: "I have a project where I'm building a large Linux router (about 40 ports or so). At this point, my only hardware solution is to purchase a box with lots of PCI-ish slots and fill them multi-port ethernet cards. I've looked into currently available solutions and haven't found anything that gives me the control I want. Does anyone know of where I could purchase a 'naked switch?' I just want the switch hardware with enough guts to allow me to customize a Linux OS and load it up." If anyone else has been in this situation, what did you do?

2 of 70 comments (clear)

  1. bandwidth limitations, and large PCI backplanes by Robbat2 · · Score: 5, Informative

    Limitations:
    - PCI bus bandwidth is going to hurt you hard. 32-bit PCI @ 33Mhz = 127Mbyte/sec. 64-bit PCI-X @ 66Mhz = 508Mbyte/sec.
    - 100Mbit ethernet = ~10Mbyte/sec (assume 10b8 encoding, easier numbers).
    - 127Mbyte/sec / ~10Mbyte/sec = 12 100Mbit ports only.

    If you aren't deterred by this:
    1. Get a motherboard.
    2. Get a decent PCI backplane. A quick Google search brings this company:
    http://www.commell.com.tw/Product/Peripheral/Backp lane/backplane.HTM
    and they have a backplane with 17 PCI slots.
    3. Buy 4-port PCI 100mbit network cards (http://www.americanpredator.com they don't list it on their site, but I'm certain they do custom quad port cards, or can point you to somebody that can, $500/card for industrial grade hardware).
    4. 17*4 = 68x 100Mbit ethernet ports.

    --
    ICQ# : 30269588
    "I used to be an idealist, but I got mugged by reality."
    1. Re:bandwidth limitations, and large PCI backplanes by kneecap · · Score: 5, Informative

      Use PCI Express instead, it has dedicated serial bandwidth to each slot instead of shared bandwidth for all PCI or PCI-X slots connected to a PCI controler.

      From http://en.wikipedia.org/wiki/List_of_device_bandwi dths
      PCI 32-bit/33 MHz 1066.66 Mbit/s 133.33 MB/s
      PCI Express (x1 link) 2500 Mbit/s 250 MB/s
      PCI 64-bit/33 MHz 2133.33 Mbit/s 266.66 MB/s
      PCI 32-bit/66 MHz 2133.33 Mbit/s 266.66 MB/s
      PCI 64-bit/66 MHz 4266.66 Mbit/s 533.33 MB/s
      PCI-X 133 8533.33 Mbit/s 1066.66 MB/s
      PCI Express (x4 link) 10000 Mbit/s 1000 MB/s
      PCI Express (x8 link) 20.00 Gbit/s 2 GB/s
      PCI Express (x16 link) 40.0 Gbit/s 4 GB/s

      The big routers and switches use PCI/PCI-X on their backplanes and when some of them started doing 10Gig ethernet ports the ran into the PCI-X bandwidth limit of abouth 8.5 Gbit. So do like Cisco & the others did and start using PCI-E. I saw another post here mentioning multiport gigabit ethernet cards for PCI-E slots made by Silicom: http://www.silicom-usa.com/