Throughput of your Gigabit switch? (performance problems with 3508G-XL)

Discussion in 'Cisco' started by Thomas Arens, Sep 27, 2004.

  1. Thomas Arens

    Thomas Arens Guest

    Hello everybody,

    I am currently benchmarking several MPI implementations for Windows, and
    I noticed that our Cisco 3508G-XL Gigabit switch (eight 1000Base-X
    ports, 10-Gbps switching fabric) performs quite bad compared to a direct
    connection between two nodes via crossover cable.

    I used two nodes (dual Xeon machines, Intel Pro/1000 MT Server Adapters,
    Windows XP Prof. SP1) and the tool "netio" (version 1.14,
    client/server-based, measures TCP/IP-throughput in one direction, Google
    for download ;-) ), once connected through the Cisco switch and once
    with a crossover cable.

    The results:

    Switch:

    Packet size 1 KByte: 32580 KByte/s
    Packet size 2 KByte: 37728 KByte/s
    Packet size 4 KByte: 30869 KByte/s
    Packet size 8 KByte: 40347 KByte/s
    Packet size 16 KByte: 69608 KByte/s
    Packet size 32 KByte: 79617 KByte/s

    Crossover cable:

    Packet size 1 KByte: 74438 KByte/s
    Packet size 2 KByte: 86279 KByte/s
    Packet size 4 KByte: 94309 KByte/s
    Packet size 8 KByte: 105423 KByte/s
    Packet size 16 KByte: 115338 KByte/s
    Packet size 32 KByte: 115516 KByte/s

    As you can see, the performance of the switch is really poor. I went
    through the configuration of the switch many times, but I could not find
    anything that would explain the bad performance, the configuration seems
    to be correct.


    How are your experiences with Gigabit switches regarding performance?
    I would greatly appreciate any statements on this topic.

    Many thanks for your time!


    Best regards,
    Thomas Arens
    Chair for Operating Systems (http://www.lfbs.rwth-aachen.de)
    RWTH Aachen University (http://www.rwth-aachen.de)
     
    Thomas Arens, Sep 27, 2004
    #1
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  2. Thomas Arens

    Ivan Ostreš Guest

    In article <>, -aachen.de
    says...
    > As you can see, the performance of the switch is really poor. I went
    > through the configuration of the switch many times, but I could not find
    > anything that would explain the bad performance, the configuration seems
    > to be correct.
    >
    >
    > How are your experiences with Gigabit switches regarding performance?
    > I would greatly appreciate any statements on this topic.
    >
    >


    It's not that unusual since when using crossover, there's no CDP, BPDU
    and other "unusefull" traffic...

    Actually I've seen that before. I tried to play with flow control and
    other stuff but was unable to get crossover-like performance. Just a tip
    - look at interface counters (utilization, broadcast & multicast
    counters). The other thing... try to put just 2 ports in a VLAN and try
    to measure (kill all CDP, BPDU and other switch stuff) that should give
    you better performance.

    --
    -Ivan.

    *** Use Rot13 to see my eMail address ***
     
    Ivan Ostreš, Sep 27, 2004
    #2
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  3. Re: Throughput of your Gigabit switch? (performance problems with3508G-XL)

    hi
    i have tryed a tool called "ipperf"
    This tool uses a 1 Gbps Link complete....


    nice greetings

    fred

    Ivan Ostreš wrote:
    > In article <>, -aachen.de
    > says...
    >
    >>As you can see, the performance of the switch is really poor. I went
    >>through the configuration of the switch many times, but I could not find
    >>anything that would explain the bad performance, the configuration seems
    >>to be correct.
    >>
    >>
    >>How are your experiences with Gigabit switches regarding performance?
    >>I would greatly appreciate any statements on this topic.
    >>
    >>

    >
    >
    > It's not that unusual since when using crossover, there's no CDP, BPDU
    > and other "unusefull" traffic...
    >
    > Actually I've seen that before. I tried to play with flow control and
    > other stuff but was unable to get crossover-like performance. Just a tip
    > - look at interface counters (utilization, broadcast & multicast
    > counters). The other thing... try to put just 2 ports in a VLAN and try
    > to measure (kill all CDP, BPDU and other switch stuff) that should give
    > you better performance.
    >
     
    fred feuerstein, Sep 27, 2004
    #3
  4. Thomas Arens

    Chris Thomas Guest

    In article <>, -aachen.de
    says...
    > Switch:
    >
    > Packet size 1 KByte: 32580 KByte/s
    > Packet size 2 KByte: 37728 KByte/s
    > Packet size 4 KByte: 30869 KByte/s
    > Packet size 8 KByte: 40347 KByte/s
    > Packet size 16 KByte: 69608 KByte/s
    > Packet size 32 KByte: 79617 KByte/s
    >
    > Crossover cable:
    >
    > Packet size 1 KByte: 74438 KByte/s
    > Packet size 2 KByte: 86279 KByte/s
    > Packet size 4 KByte: 94309 KByte/s
    > Packet size 8 KByte: 105423 KByte/s
    > Packet size 16 KByte: 115338 KByte/s
    > Packet size 32 KByte: 115516 KByte/s
    >
    > As you can see, the performance of the switch is really poor.


    I recently did something similar with a 6509 (720 sup, 6748 line
    cards) while looking for another problem, and at a first
    approximation, I didn't see any difference between going through the
    switch and using a crossover (actually GB does auto-cross, so I used
    a straight cable). My numbers were about 930 mbits/sec in both
    cases. I would agree that your 'switch' numbers are really poor, but
    have no suggestions beyond that.

    /Chris, UCLA
     
    Chris Thomas, Sep 27, 2004
    #4
  5. "Thomas Arens" <-aachen.de> wrote in message
    news:2rqhidF1d5lbeU1@uni-
    > Switch:
    >
    > Packet size 1 KByte: 32580 KByte/s
    > Packet size 2 KByte: 37728 KByte/s
    > Packet size 4 KByte: 30869 KByte/s
    > Packet size 8 KByte: 40347 KByte/s
    > Packet size 16 KByte: 69608 KByte/s
    > Packet size 32 KByte: 79617 KByte/s
    >
    > Crossover cable:
    >
    > Packet size 1 KByte: 74438 KByte/s
    > Packet size 2 KByte: 86279 KByte/s
    > Packet size 4 KByte: 94309 KByte/s
    > Packet size 8 KByte: 105423 KByte/s
    > Packet size 16 KByte: 115338 KByte/s
    > Packet size 32 KByte: 115516 KByte/s


    yeah - shitty perfm in that sw.

    I seem to recall that the 3500 have limited framesize support, if any-
    beyond 2k frames.
    I would look into that, If I were you.
    Looks like the switch are config'ed for some MTU and/or frame-size, that has
    a mis-match between the NIC and the port. (btw was that copper ports in the
    GBIC?)
    btw you dont need cross-over for 1000base-t NICs, and remember that
    1000base-t uses all 4 pairs as well, so be very sure you use brand new Cat-6
    or 5e (I use Cat.6 with each pair seperated by a plastic X inside the
    cable).

    But I would use an other switch that supports large frames.

    HTH
    Martin Bilgrav
     
    Martin Bilgrav, Sep 27, 2004
    #5
  6. Hi,

    Oops, There's always the difference between frames and packets. Normally
    (ofcourse there are jumbo-frames), frames do not exceed aprox 1500 bytes in
    size. Packets can get larger and will be devided over one or more frames.

    So framesize is not an issue here!

    Erik


    "Martin Bilgrav" <> wrote in message
    news:gZZ5d.53154$...
    >
    > "Thomas Arens" <-aachen.de> wrote in message
    > news:2rqhidF1d5lbeU1@uni-
    > > Switch:
    > >
    > > Packet size 1 KByte: 32580 KByte/s
    > > Packet size 2 KByte: 37728 KByte/s
    > > Packet size 4 KByte: 30869 KByte/s
    > > Packet size 8 KByte: 40347 KByte/s
    > > Packet size 16 KByte: 69608 KByte/s
    > > Packet size 32 KByte: 79617 KByte/s
    > >
    > > Crossover cable:
    > >
    > > Packet size 1 KByte: 74438 KByte/s
    > > Packet size 2 KByte: 86279 KByte/s
    > > Packet size 4 KByte: 94309 KByte/s
    > > Packet size 8 KByte: 105423 KByte/s
    > > Packet size 16 KByte: 115338 KByte/s
    > > Packet size 32 KByte: 115516 KByte/s

    >
    > yeah - shitty perfm in that sw.
    >
    > I seem to recall that the 3500 have limited framesize support, if any-
    > beyond 2k frames.
    > I would look into that, If I were you.
    > Looks like the switch are config'ed for some MTU and/or frame-size, that

    has
    > a mis-match between the NIC and the port. (btw was that copper ports in

    the
    > GBIC?)
    > btw you dont need cross-over for 1000base-t NICs, and remember that
    > 1000base-t uses all 4 pairs as well, so be very sure you use brand new

    Cat-6
    > or 5e (I use Cat.6 with each pair seperated by a plastic X inside the
    > cable).
    >
    > But I would use an other switch that supports large frames.
    >
    > HTH
    > Martin Bilgrav
    >
    >
     
    Erik Tamminga, Sep 27, 2004
    #6
  7. "Erik Tamminga" <> wrote in message
    news:cj9tqa$jhm$1.ov.home.nl...
    > Hi,
    >
    > Oops, There's always the difference between frames and packets. Normally
    > (ofcourse there are jumbo-frames), frames do not exceed aprox 1500 bytes

    in
    > size. Packets can get larger and will be devided over one or more frames.
    >
    > So framesize is not an issue here!


    I couldn't disagree more - your throughput, in regards to GE, very much
    depends on the framesize.

    Why is it called Jumbo-"frames" then ?
    Anyway, that is what I mean. I use the term frame as in Jumbo frames.
    read this:
    http://sd.wareonearth.com/~phil/jumbo.html

    or

    To qoute the well recommended book TCP/IP Network Administration Guide 3rd
    edition, by Craig Hunt:

    "Figure 1-4 shows the terms used by different layers of TCP/IP to refer to
    the data being transmitted. Applications using TCP refer to data as a
    stream, while applications using UDP refer to data as a message. TCP calls
    data a segment, and UDP calls its data a packet. The Internet layer views
    all data as blocks called datagrams. TCP/IP uses many different types of
    underlying networks, each of which may have a different terminology for the
    data it transmits. Most networks refer to transmitted data as packets or
    frames. Figure 1-4 shows a network that transmits pieces of data it calls
    frames. "

    anyway the fact is that both packets and frames are handeld at layer-2.
    Just depends upon the direction: if its from layer-1 to layer-2 = frame, if
    its from layer-3 to layer-2 = packet.
    I sugguest, if you what to discuss lingo, you open a new thread with this
    issue.

    With Kind Regards

    Martin Bilgrav
     
    Martin Bilgrav, Sep 27, 2004
    #7
  8. Thomas Arens

    AnyBody43 Guest

    > > "Thomas Arens" <-aachen.de> wrote
    > > > Switch:
    > > >
    > > > Packet size 1 KByte: 32580 KByte/s
    > > > Packet size 2 KByte: 37728 KByte/s
    > > > Packet size 4 KByte: 30869 KByte/s
    > > > Packet size 8 KByte: 40347 KByte/s
    > > > Packet size 16 KByte: 69608 KByte/s
    > > > Packet size 32 KByte: 79617 KByte/s
    > > >
    > > > Crossover cable:
    > > >
    > > > Packet size 1 KByte: 74438 KByte/s
    > > > Packet size 2 KByte: 86279 KByte/s
    > > > Packet size 4 KByte: 94309 KByte/s
    > > > Packet size 8 KByte: 105423 KByte/s
    > > > Packet size 16 KByte: 115338 KByte/s
    > > > Packet size 32 KByte: 115516 KByte/s


    This is pretty much what is to be expected, IF the test software
    is sending one packet at a time and then waiting for it to
    be acknowledged before sending another one.

    I don't have time to go through it all now.

    Try testing with something that does TCP windowing such as ttcp.
    Check the actual window sizes in use with windump/tcpdump.
    If your test is already doing windowing then clearly this may
    be of concern.

    I don't know the particular switch.
     
    AnyBody43, Sep 28, 2004
    #8
  9. Thomas Arens

    Ivan Ostreš Guest

    In article <>, anybody43
    @hotmail.com says...
    > > > "Thomas Arens" <-aachen.de> wrote
    > > > > Switch:
    > > > >
    > > > > Packet size 1 KByte: 32580 KByte/s
    > > > > Packet size 2 KByte: 37728 KByte/s
    > > > > Packet size 4 KByte: 30869 KByte/s
    > > > > Packet size 8 KByte: 40347 KByte/s
    > > > > Packet size 16 KByte: 69608 KByte/s
    > > > > Packet size 32 KByte: 79617 KByte/s
    > > > >
    > > > > Crossover cable:
    > > > >
    > > > > Packet size 1 KByte: 74438 KByte/s
    > > > > Packet size 2 KByte: 86279 KByte/s
    > > > > Packet size 4 KByte: 94309 KByte/s
    > > > > Packet size 8 KByte: 105423 KByte/s
    > > > > Packet size 16 KByte: 115338 KByte/s
    > > > > Packet size 32 KByte: 115516 KByte/s

    >
    > This is pretty much what is to be expected, IF the test software
    > is sending one packet at a time and then waiting for it to
    > be acknowledged before sending another one.
    >
    > I don't have time to go through it all now.
    >
    > Try testing with something that does TCP windowing such as ttcp.
    > Check the actual window sizes in use with windump/tcpdump.
    > If your test is already doing windowing then clearly this may
    > be of concern.
    >
    > I don't know the particular switch.
    >


    Actually it would be pretty stupid to test maximal troughput using TCP
    anyway. If you really want to get maximum you should use some UDP based
    tool.


    --
    -Ivan.

    *** Use Rot13 to see my eMail address ***
     
    Ivan Ostreš, Sep 28, 2004
    #9
  10. Thomas Arens

    Guest

    Also keep in mind that the 3508 doesn't really support full gigabit
    speeds on all ports at once. Ports 1&2, 3&4, 5&6, and 7&8 share an
    asic (4 total). Each asic can only support 1 gigabit throughput.
    Thus if you have ports 1 and 2 loaded down, they can only total 1 gig.


    -Chris

    On Mon, 27 Sep 2004 15:06:21 +0200, Thomas Arens
    <-aachen.de> wrote:

    >Hello everybody,
    >
    >I am currently benchmarking several MPI implementations for Windows, and
    >I noticed that our Cisco 3508G-XL Gigabit switch (eight 1000Base-X
    >ports, 10-Gbps switching fabric) performs quite bad compared to a direct
    >connection between two nodes via crossover cable.
    >
    >I used two nodes (dual Xeon machines, Intel Pro/1000 MT Server Adapters,
    >Windows XP Prof. SP1) and the tool "netio" (version 1.14,
    >client/server-based, measures TCP/IP-throughput in one direction, Google
    >for download ;-) ), once connected through the Cisco switch and once
    >with a crossover cable.
    >
    >The results:
    >
    >Switch:
    >
    >Packet size 1 KByte: 32580 KByte/s
    >Packet size 2 KByte: 37728 KByte/s
    >Packet size 4 KByte: 30869 KByte/s
    >Packet size 8 KByte: 40347 KByte/s
    >Packet size 16 KByte: 69608 KByte/s
    >Packet size 32 KByte: 79617 KByte/s
    >
    >Crossover cable:
    >
    >Packet size 1 KByte: 74438 KByte/s
    >Packet size 2 KByte: 86279 KByte/s
    >Packet size 4 KByte: 94309 KByte/s
    >Packet size 8 KByte: 105423 KByte/s
    >Packet size 16 KByte: 115338 KByte/s
    >Packet size 32 KByte: 115516 KByte/s
    >
    >As you can see, the performance of the switch is really poor. I went
    >through the configuration of the switch many times, but I could not find
    >anything that would explain the bad performance, the configuration seems
    >to be correct.
    >
    >
    >How are your experiences with Gigabit switches regarding performance?
    >I would greatly appreciate any statements on this topic.
    >
    >Many thanks for your time!
    >
    >
    >Best regards,
    >Thomas Arens
    >Chair for Operating Systems (http://www.lfbs.rwth-aachen.de)
    >RWTH Aachen University (http://www.rwth-aachen.de)
     
    , Oct 3, 2004
    #10
  11. Thomas Arens

    Thomas Arens Guest

    Re: Throughput of your Gigabit switch? (performance problems with3508G-XL)

    schrieb:
    >
    > Also keep in mind that the 3508 doesn't really support full gigabit
    > speeds on all ports at once. Ports 1&2, 3&4, 5&6, and 7&8 share an
    > asic (4 total). Each asic can only support 1 gigabit throughput.


    Thanks for the information, but I think in this benchmark that's
    irrelevant, since one node sends and the other receives.

    It is interesting thinking of the MPI performance with 8 nodes though.
     
    Thomas Arens, Oct 4, 2004
    #11
  12. Thomas Arens

    Thomas Arens Guest

    Re: Throughput of your Gigabit switch? (performance problems with3508G-XL)

    Ivan Ostreš wrote:
    >
    > Actually it would be pretty stupid to test maximal troughput using TCP
    > anyway. If you really want to get maximum you should use some UDP based
    > tool.


    I don't think so, because TCP is quite realistic for many applications. ;-)
    Benchmarking UDP performance would deliver quite theoretical results.
     
    Thomas Arens, Oct 4, 2004
    #12
  13. Thomas Arens

    Thomas Arens Guest

    Re: Throughput of your Gigabit switch? (performance problems with3508G-XL)

    Martin Bilgrav schrieb:

    > I seem to recall that the 3500 have limited framesize support, if any-
    > beyond 2k frames.


    Jumbo frames are not supported, yes.

    > I would look into that, If I were you.
    > Looks like the switch are config'ed for some MTU and/or frame-size, that has
    > a mis-match between the NIC and the port.


    I checked the MTU sizes. They should be correct.

    > (btw was that copper ports in the
    > GBIC?)


    Yes.

    > btw you dont need cross-over for 1000base-t NICs, and remember that
    > 1000base-t uses all 4 pairs as well, so be very sure you use brand new Cat-6
    > or 5e (I use Cat.6 with each pair seperated by a plastic X inside the
    > cable).


    I used quite short (a few meters long) Cat 5e cables with the
    inscription "verified for gigabit ethernet" or something like that. I do
    not have Cat 6 cables to play with...

    > But I would use an other switch that supports large frames.


    Hehe... you know, money _is_ an issue. ;-)

    Thanks!

    Thomas Arens
    Chair for Operating Systems (http://www.lfbs.rwth-aachen.de)
    RWTH Aachen University (http://www.rwth-aachen.de)
     
    Thomas Arens, Oct 4, 2004
    #13
  14. Thomas Arens

    Thomas Arens Guest

    Re: Throughput of your Gigabit switch? (performance problems with3508G-XL)

    Chris Thomas schrieb:

    > at a first
    > approximation, I didn't see any difference between going through the
    > switch and using a crossover
    > [...]
    > I would agree that your 'switch' numbers are really poor, but
    > have no suggestions beyond that.


    Thanks, that's good to know.
     
    Thomas Arens, Oct 4, 2004
    #14
  15. Thomas Arens

    Ivan Ostreš Guest

    Re: Throughput of your Gigabit switch? (performance problems with 3508G-XL)

    In article <>, -aachen.de
    says...
    > Ivan Ostreš wrote:
    > >
    > > Actually it would be pretty stupid to test maximal troughput using TCP
    > > anyway. If you really want to get maximum you should use some UDP based
    > > tool.

    >
    > I don't think so, because TCP is quite realistic for many applications. ;-)
    > Benchmarking UDP performance would deliver quite theoretical results.
    >


    Just partially true. TCP is quite realistic for many applications but
    you will not actually measure the limits of the switch. So, you have to
    ask yourself what do you actually want to measure: how fast your
    application will be using specified hardware or how much packets
    (bytes/whatever) can hardware handle?

    It's simple as that. Someone said (i think it was my university teacher)
    that measuring something when you haven't defined what do you really
    want and didn't choose right way is worth nothing.


    --
    -Ivan.

    *** Use Rot13 to see my eMail address ***
     
    Ivan Ostreš, Oct 4, 2004
    #15
  16. Thomas Arens

    Hansang Bae Guest

    In article <>, -aachen.de
    says...
    > Hello everybody,
    >
    > I am currently benchmarking several MPI implementations for Windows, and
    > I noticed that our Cisco 3508G-XL Gigabit switch (eight 1000Base-X
    > ports, 10-Gbps switching fabric) performs quite bad compared to a direct
    > connection between two nodes via crossover cable.
    >
    > I used two nodes (dual Xeon machines, Intel Pro/1000 MT Server Adapters,
    > Windows XP Prof. SP1) and the tool "netio" (version 1.14,
    > client/server-based, measures TCP/IP-throughput in one direction, Google
    > for download ;-) ), once connected through the Cisco switch and once
    > with a crossover cable.
    >
    > The results:
    >
    > Switch:
    >
    > Packet size 1 KByte: 32580 KByte/s
    > Packet size 2 KByte: 37728 KByte/s
    > Packet size 4 KByte: 30869 KByte/s
    > Packet size 8 KByte: 40347 KByte/s
    > Packet size 16 KByte: 69608 KByte/s
    > Packet size 32 KByte: 79617 KByte/s
    >
    > Crossover cable:
    >
    > Packet size 1 KByte: 74438 KByte/s
    > Packet size 2 KByte: 86279 KByte/s
    > Packet size 4 KByte: 94309 KByte/s
    > Packet size 8 KByte: 105423 KByte/s
    > Packet size 16 KByte: 115338 KByte/s
    > Packet size 32 KByte: 115516 KByte/s
    >
    > As you can see, the performance of the switch is really poor. I went
    > through the configuration of the switch many times, but I could not find
    > anything that would explain the bad performance, the configuration seems
    > to be correct.
    >
    >
    > How are your experiences with Gigabit switches regarding performance?
    > I would greatly appreciate any statements on this topic.
    >
    > Many thanks for your time!



    Somethings to consider. Take Cisco's claimed numbers and then chop it in
    half. That's a start. Do you have the spec sheet handy?

    Try the following:
    1) use auto/auto on both NICs.
    2) Use ports 1/2 instead of 1/7 for example. It could be asic level
    issues going on here.



    --

    hsb

    "Somehow I imagined this experience would be more rewarding" Calvin
    *************** USE ROT13 TO SEE MY EMAIL ADDRESS ****************
    ********************************************************************
    Due to the volume of email that I receive, I may not not be able to
    reply to emails sent to my account. Please post a followup instead.
    ********************************************************************
     
    Hansang Bae, Oct 5, 2004
    #16
  17. Thomas Arens

    Thomas Arens Guest

    Re: Throughput of your Gigabit switch? (performance problems with3508G-XL)

    Ivan Ostreš schrieb:
    > Just partially true. TCP is quite realistic for many applications but
    > you will not actually measure the limits of the switch. So, you have to
    > ask yourself what do you actually want to measure: how fast your
    > application will be using specified hardware or how much packets
    > (bytes/whatever) can hardware handle?


    True. And I want to know how fast the switch can handle TCP packets. I
    did think about that. ;-)

    - The background is: I'm benchmarking several MPI implementations for
    Windows, and I noticed that the switch seems to be quite slow. Now I'm
    trying to find out if the performance is "normal" for a Gigabit switch
    and if not, how I could make it perform better.


    Best regards,
    Thomas Arens
    Chair for Operating Systems (http://www.lfbs.rwth-aachen.de)
    RWTH Aachen University (http://www.rwth-aachen.de)
     
    Thomas Arens, Oct 6, 2004
    #17
  18. Thomas Arens

    Steinar Haug Guest

    Re: Throughput of your Gigabit switch? (performance problems with3508G-XL)

    [Thomas Arens]

    | > Just partially true. TCP is quite realistic for many applications but
    | > you will not actually measure the limits of the switch. So, you have to
    | > ask yourself what do you actually want to measure: how fast your
    | > application will be using specified hardware or how much packets
    | > (bytes/whatever) can hardware handle?
    |
    | True. And I want to know how fast the switch can handle TCP packets. I
    | did think about that. ;-)

    If this is a normal L2 switch is has *no idea* that your packets are TCP
    packets.

    If you want a realistic measurement of switch throughput, you need
    measurement equipment designed for this - Smartbits or similar.

    Steinar Haug, Nethelp consulting,
     
    Steinar Haug, Oct 6, 2004
    #18
  19. Thomas Arens

    Ivan Ostreš Guest

    Re: Throughput of your Gigabit switch? (performance problems with 3508G-XL)

    In article <>, says...
    > [Thomas Arens]
    >
    > | > Just partially true. TCP is quite realistic for many applications but
    > | > you will not actually measure the limits of the switch. So, you have to
    > | > ask yourself what do you actually want to measure: how fast your
    > | > application will be using specified hardware or how much packets
    > | > (bytes/whatever) can hardware handle?
    > |
    > | True. And I want to know how fast the switch can handle TCP packets. I
    > | did think about that. ;-)
    >
    > If this is a normal L2 switch is has *no idea* that your packets are TCP
    > packets.
    >


    Of course it has *no idea* that packets are TCP, but endpoints
    (computers) are very aware of that ;-).


    --
    -Ivan.

    *** Use Rot13 to see my eMail address ***
     
    Ivan Ostreš, Oct 6, 2004
    #19
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