Conference 7.286::fddi

>>- does DEFEA support full-duplex FDDI?? (In case of any dependency, special
>>  interest in SAS version, and the UTP variant).

    Yes.  Full-Duplex mode (eFDXEnable MIB object) is disabled by default,
    but can be enabled either through a driver switch or local management
    utility (DEClma).  FDX is supported on all three variants of the DEFEA
    (SAS, DAS, and UTP).  Which driver are you considering using?
    
>>- if DEFEA does support FDX, can this feature be used in a configuration when
>>  a SAS DEFEA is configured in a point-to-point connection to a SAS port
>>  of GIGAswitch at a 4-port FGL?

    Yes.  Once enabled, the adapter will enter full-duplex mode when
    connected point-point with a similarly enabled FDDI adapter, or when
    attached to a Digital GIGAswitch port that (I believe) enables FDX by
    default.
    
       - Larry Stefani
         DEFEA Product Engineering
          

Thanks for confirmation.

I'm considering a use of UTP DEFEA versions against GIGAswitch ports...

Regards Petr.

>>I'm considering a use of UTP DEFEA versions against GIGAswitch ports...
    
    Yes, but running what operating system?  Using which driver?
    
    Note: Full-duplex mode will help to reduce latency, but you won't see
    any increase in aggregate throughput unless you're really driving close
    to 100Mbps.  We have seen FDX push throughput over 100Mbps using two
    Alphas running OSF/1 with two DEFTA's (TURBOchannel FDDI) and also
    using two COMPAQ Proliants running NetWare SFT III 3.11 with two
    DEFEA's (EISA FDDI).
    
       - Larry

    
    	GIGAswitch does enable FDX by default.

    
    Where is this DEClma utility? I want to turn on full duplex for a
    customer test.

    >>Where is this DEClma utility? I want to turn on full duplex for a
    >>customer test.
    
    Most of the DEFEA/DEFPA drivers offer a switch for enabling
    Full-Duplex.  Which driver are you working with?
    
    /l

    
    OpenVMS AXP V6.1. I want to make sure I can switch this into full
    duplex since according to this note stream, the DEFEA may not be in
    full duplex mode by default. My other systems are DEFTA-FA based and
    their default according to another note is full duplex.

    >>OpenVMS AXP V6.1. I want to make sure I can switch this into full
    >>duplex since according to this note stream, the DEFEA may not be in
    >>full duplex mode by default. My other systems are DEFTA-FA based and
    >>their default according to another note is full duplex.
    
    I thought that there was a note posted that described the VMS command
    line for setting/viewing various adapter characteristics.  Perhaps Dick
    Stockdale can post the method for enabling FDX.
    
    /l

With V6.1, the full-duplex capability is enabled by adapter default
only.  Since it is disabled by default in the DEFEA, you can't enable
full duplex with versions of VMS prior to V6.2.  In V6.2, the LANCP
utility allows you to issue the command SET DEV FRA0/FULL_DUPLEX.

- Dick

    
    So, there is absolutely no way to change this?
    
    What is the default for the DEFPA-xx controllers?

No full duplex.

    
    Is this a settable parameter in a flash on the controller card? I have
    an MS-Windows PCI system which I could set it up for a customer test to
    test out GIGAswitch capabilities.
    
    What is the rationale behind disabling this feature which we tout so
    highly?
    

    >>So, there is absolutely no way to change this?
    
    I thought Dick did a good job of explaining how to change this in .9.
    Is upgrading to 6.2 a problem?
    
    >>What is the default for the DEFPA-xx controllers?
    
    The DEFEA and DEFPA controller firmware leave optional features such as
    FDX enable and ring purger enable OFF by default in the firmware.  The
    driver can (of course) always enable it during driver initialization,
    but most of our drivers now offer command line switches for
    enabling/disabling FDX during driver init and some drivers have
    management application support for enabling/disabling FDX during
    run-time.
    
       - Larry

    >>Is this a settable parameter in a flash on the controller card? I have
    >>an MS-Windows PCI system which I could set it up for a customer test to
    >>test out GIGAswitch capabilities.
    
    Which MS-Windows PCI driver are you planning to run?  The DOS ODI
    client driver does have an FDX enable switch in NET.CFG.  The DOS NDIS
    2.01 driver does not, however.
    
    >>What is the rationale behind disabling this feature which we tout so
    >>highly?
    
    Networks Engineering got beat up pretty bad from the field for enabling
    optional features such as ring purger by default.  When we started the
    DEFEA program, we decided that these features are optional and that
    users should enable them if they want to.
    
    As engineers we can state that both the ring purger protocol and FDX
    protocol are NOT detrimental to standard FDDI rings, however, there are
    undoubtedly non-standard nodes on customer networks that might have
    problems.  For example, nodes that copy VOID frames by default get
    burned pretty bad when the purger is running.
    
       - Larry
    

    re: .13
    
    Yes, there is. Although we as Digital like to recommend upgrades,
    customers developing and deploying applications don't have this luxury. 
    It's Digital's common engineering mistake that customers will always
    upgrade to the latest version. 
    
    So, in my case I have a problem. Customer can't upgrade to 6.2, I'm
    trying to demonstrate the full duplex capabilities of a GIGAswitch and
    the default setting of the controller make this test now impossible. 
    
    If the controller auto-senses and determines that it can use full
    duplex, what's the harm in making this the default? So, I'm out of luck
    and won't be able to demonstrate the full duplex capability of our
    GIGAswitch with Digital products. It's very frustrating...

    
    re: .14
    
    I understand about getting beat up. However, requiring a version of an
    operating system to enable it is really frustrating. It would be nice
    if there was some sort of method of turning it on in versions of
    OpenVMS which support the controller, i.e. V6.1 for the DEFEA, DEFPA.
    My customer simply can't upgrade now and we can't show how how good it
    is.

    >>Yes, there is. Although we as Digital like to recommend upgrades,
    >>customers developing and deploying applications don't have this luxury. 
    >>It's Digital's common engineering mistake that customers will always
    >>upgrade to the latest version. 
    
    Look around.  This isn't just Digital's approach, but also our
    competitors (Novell, Microsoft, SCO, IBM).  I think we do much more in
    terms of backwards compatibility and support of older OS's than many
    other companies.  Our FDDI driver diskettes still contain driver
    patches for NetWare 3.11 which is (by now) a 4-year old operating
    system, so we are sensitive to this.
    
    >>If the controller auto-senses and determines that it can use full
    >>duplex, what's the harm in making this the default? So, I'm out of luck
    >>and won't be able to demonstrate the full duplex capability of our
    >>GIGAswitch with Digital products. It's very frustrating...
    
    Though we tout Full Duplex as the best thing since sliced bread, FDX
    may help latency, but it won't increase throughput unless you're
    driving close to line speed.  Unless you're running the Bricks demo,
    you generally won't see a performance benefit from enabling it.  Now,
    GIGAswitch to GIGAswitch is another story.
    
    /l
                                                  

    
    Yes, latency is the problem I'm trying to solve. In addition, thruput
    is also one of the things I'm looking at since this is a medical
    imaging application. We want to break the 100Mb barrier with the
    controller/GIGAswitch combination. 
    
    I am also aware of our long-standing tradition of long term support. I
    always touted that when I was an OpenVMS Partner. It would have been
    nice if the advertising reflected this also, but I digress...
    
    So, in my case, is there anything which can be done to enable full
    duplex on the system besides upgrading to V6.2? Or should I just forget
    it?

If I recall, fdx was good for 110 mbits/sec on a DEMFA, 160 on a DEFTA,
130 on a DEFEA.  Is it even worth considering on the DEFEA?

I looked at the driver code to do it and it would require the driver
to issue a set_snmp command to the DEFEA, which is not much work to
do.  I sent you an untested driver via email.

- Dick