1x QSFP+ to 4x SFP+ == 4 interfaces?



  • Hello,

    has anyone already tested those Chelsio tools tested on PFSense (=> http://service.chelsio.com/beta/drivers/freebsd_tool/README.txt)?
    According to it:

    QSA: This mode adds support for QSA (QSFP to SFP+) modules, enabling smooth,
        cost-effective, connections between 40 Gigabit Ethernet adapters and 1 or
        10 Gigabit Ethernet networks using existing SFP+ based cabling.
        The port farthest from the motherboard will be Port 0 (least MAC Address)."

    So, when using those I can "convert" those 2x QSFP+ ports into 8x 10SFP+ ports, right?

    • Is this even possible with Intel X710 NICs?

    (Currently, I´m looking for a low profile card for the pfSense XG-1540. While using 2.5" HDDs I can only put in low profile NICs. With QSFP+ to SFP+ adapters it seems I could have 8x SFP+)



  • As I was reading and understanding it right, it must match the following:

    • 2X40Gbps:
      This is the adapter's default mode of operation where each port functions as a 40Gbps link.
      The port nearest to the motherboard will be Port 0 (least MAC Address).
      So you will be getting 2 x 40 GBit/s out

    • 4X10Gbps:
      In this mode, port 0 functions as 4 x 10Gbps links and port 1 is disabled.
      So it can not be that you will be getting 8 x 10 GBit/s

    • QSA:
      This mode adds support for QSA (QSFP to SFP+) modules, enabling smooth,
      cost-effective, connections between 40 Gigabit Ethernet adapters and 1 GBit/s
      or 10 Gigabit Ethernet networks using existing SFP+ based cabling.
      The port farthest from the motherboard will be Port 0 (least MAC Address).
      _So you are able to get in my eyes only;
      – 4 x 10 GBit/s (one port is disabled)
      -- 8 x 1 GBit/s (Both ports are in use)

    So, when using those I can "convert" those 2x QSFP+ ports into 8x 10SFP+ ports, right?

    No! Because one port is then disabled, so you could get only 4 x 10 GBit/s at one port.
    If 8 x is supported this would be as I was understanding it then more to the 1 GBit/s
    so then if you will have a closer look to the adapter both ports will be able to use.
    Chelsio QSFP+ / 4xSFP+ 3m QSFP+ 4 x SFP+ 3 m OCTTAPCABLE3M

    Chelsio T520-SO-CR as a LAN adapter to feed and connect switches or devices
    Chelsio T520-CR as a WAN Adapter for totally offloading NAT as an example
    Connecting some switches like the Netgear XS708E or XS712T over LAG (LACP)
    this would be really nice I must consider, but if switches got stacked I prefer
    it to LAG on times the whole stack.

    • Is this even possible with Intel X710 NICs?

    No, only the Intel XL710 is a 40 GBit/s NIC that supports this
    function also over breakout cables!

    Another aspect of 40 GbE-based products like the XL710 is that each QSFP port
    can utilize QSFP-to-4x SFP+ breakout cables.

    Read the full article here

    acknowledgement of copyright_



  • Hi thanks for the information

    @BlueKobold:

    – 8 x 1 GBit/s (Both ports are in use)

    I cannot find anything about that "8x 1Gbit/s" limit, though (in QSA mode)

    Sad, the XL710 doesn´t support 8x 10Gbe:
    http://www.intel.com/content/www/us/en/embedded/products/networking/qsfp-configuration-utility-quick-usage-guide.html

    • 1x40 to enable a single QSFP+ port in 40 Gb/s mode.
    • 2x40 to enable dual QSFP+ ports in 40 Gb/s mode.
    • 4x10 for using a single QSFP+ port and breakout cable (connection to four 10 Gb/s SFP+ link
    partners).
    • 2x2x10 for using dual QSFP+ ports with breakout cables (connection to two 10 Gb/s SFP+ link
    partners for each QSFP+ port).

    Chelsio T520-CR as a WAN Adapter for totally offloading NAT as an example

    But no NAT offloading support for FreeBSD/PFSense? (=> http://www.freebsd.org/cgi/man.cgi?query=cxgbe&sektion=4)

    Btw, is there any difference between the T580/T540/T520 NICs except the size and port types?



  • I cannot find anything about that "8x 1Gbit/s" limit, though (in QSA mode)

    The it is also only 4 x 1 GBit/s also.

    Sad, the XL710 doesn´t support 8x 10Gbe:

    As I wrote can utilize QSFP-to-4x SFP+ breakout cables.

    • 4 x SFP+ and not more a

    But no NAT offloading support for FreeBSD/PFSense?

    Perhaps this would be a function in the firmware of this adapter, other wise if the
    most functions would not be able to used, why offer then this adapter for $799?

    Perhaps you ask this at the pfSense shop directly as a presales questioin they
    would know it better as they are able to insert the NIC in a pfSense box!

    PCI Express Gen3 x8
    Low Latency
    Supports Up to 1M Connections
    Full TCP and UDP offload
    Full iSCSI, FCoE offload
    Full iWARP RDMA offload
    Full NAT offload
    EVB, Flex10, VNTag
    PCI-SIG SR-IOV
    Integrated media streaming offload
    Traffic filtering & management

    Btw, is there any difference between the T580/T540/T520 NICs except the size and port types?

    The ASIC on them is the most different thing such as the by side coming functions and then on top the price
    at least for sure.