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Conference 7.286::fddi

Title:FDDI - The Next Generation
Moderator:NETCAD::STEFANI
Created:Thu Apr 27 1989
Last Modified:Thu Jun 05 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:2259
Total number of notes:8590

1689.0. "Dual SAS re-visited please" by MERIDN::GOLDSTEIN (A1%OA-I-CNFSD, OA$CONFUSED) Tue May 16 1995 13:36

    I have a customer that would like to attach 2 FDDI controller cards
    (SAS) to a DEC 3000-600 workstation.  While there is space for the
    boards a they had a few questions:
    
    1) Will Open VMS support this configuration
    
    2) Will the two sas boards operate within a das fiber ring, such that
    each one is connected to a seperate ring.  i.e. one is attached to the
    ring operating in one direction and the other controller is attached to
    the ring in the opposite direction.
    
    3) Will the two SAS controllers be able to operate like a single DAS
    card (providing for failover)?
    
    Thanks,
    
    Rob
T.RTitleUserPersonal
Name		DateLines
1689.1MERIDN::GOLDSTEINA1%OA-I-CNFSD, OA$CONFUSEDTue May 16 1995 16:086
    If anyone can answer .0 as a possible solution, can anyone articulate
    how VMS would be setup to accomodate this configuration?
    
    Thanks,
    
    Rob
1689.2NETCAD::STEFANIWelcome to the Revolution!Tue May 16 1995 16:5427
    >>1) Will Open VMS support this configuration
    
    Don't know.
    
    >>2) Will the two sas boards operate within a das fiber ring, such that
    >>each one is connected to a seperate ring.  i.e. one is attached to the
    >>ring operating in one direction and the other controller is attached to
    >>the ring in the opposite direction.
    
    If you mean, "Can the two SAS boards function as a single DAS board on
    the dual ring" then the answer is no.  At best, they'll function as two
    separate single-attachment station devices connected to either the
    same, or different rings.  Of course, if they're connected to the SAME
    ring, most protocols will have trouble being bound to both cards.  If
    they're on separate rings, that's not usually a problem, though the
    benefit depends on whether the applications can accept more than 1
    network interface.
    
    >>3) Will the two SAS controllers be able to operate like a single DAS
    >>card (providing for failover)?
    
    Nope.  Nada.
    
    Let's ask the quasi-obvious question...what exactly is it that your
    customer is trying to do?
    
    /Larry
1689.32 SAS <> 1 DASMERIDN::GOLDSTEINA1%OA-I-CNFSD, OA$CONFUSEDWed May 17 1995 11:3112
    It sounds like I have the answer that we needed... the two SAS connects
    are not really going to give them the save functionality they were
    looking for that a DAS provides.
    
    What they are trying to do is utilize existing copper wire to
    facilitate a low cost connection.  Many customers already have
    acceptable copper for a SAS but would have to wire for a DAS.
    
    Thanks,
    
    Rob
1689.4How about ...?LARVAE::HARVEYBaldly going into the unknown...Fri May 19 1995 09:124
   Is it possible (or suitable/cost-effective) to run the RJ45 (?) copper leads 
   into a DECconcentrator 900 A & B ports (via modular PMDs) and then connect 
   the end station in to the M ports using a DAS adapter. The concentrator 
   could connect its "uplinks" to the main ring using Dual-Homed links.
1689.5STAR::STOCKDALETue Jun 06 1995 09:455
>>    1) Will Open VMS support this configuration

Yes.

- Dick