Conference 7.286::fddi

1111.0. "Two SAS's to replace a DAS?" by CAATS::VINES () Tue Oct 12 1993 21:58

    A theoretical question from a customer.
    
    I have a customer who is working on a network configuration that was
    originally specified as Alpha AXP or VaxStations connected onto two
    Ethernet segments with two separate ethernet cards. This config.
    was set up to provide load balancing of data and backup in case of
    a link failure on a segment.
    
    The new requirement is now to go FDDI, and for some strange reason
    they have a large supply of SAS interface cards (not actually true!)
    Is it possible to install two SAS cards onto the workstations and
    attach them to different physical rings to provide the same load
    balancing and backup functionality they enjoy with ethernet?
    
    Is it even physically possible to install two SAS cards on an Alpha
    AXP, or a VaxStation?
    
    Can anyone explain to me how the optical bypass function works?
    
    Thanks
    
    Phil.

    The DECpc AXP 150 is an EISA bus machine, and can physically support
    multiple SAS FDDI EISA controllers (DEFEA-AA), however it depends on
    the device driver and the operating system as to whether the machine
    will support multiple cards or provide the functionality that you're
    looking for (ie load balancing).  I don't know about the other Alpha
    machines (Cobra, Flamingo, etc) but the same rules apply about the
    driver and OS.
    
       - Larry

    Read notes 320.* in this conference for an explanation of the optical
    bypass.
    
       - Larry