Conference 7.286::fddi

149.0. "Long-haul fibre grades ?" by LARVAE::HARVEY (Baldly going into the unknown...) Fri Oct 05 1990 12:25

    I have a customer (a Utility company) looking towards disaster and
    contingency planning and wanting to split clusters over 2 sites approx.
    7 miles apart. FDDI clustering would appear to be a very attractive
    longer-term goal to aim for.
    
    My questions :-
    
    Is there a standard for monomode fibres for use over longer distances
    or has this yet to be argued/discussed/agreed ?
    
    If there is a cable our customers can install now (or soon) can they
    use it for other protocols and equipment, like Ethernet and Bridges for 
    instance, while they wait for the suppliers to provide the various     
    hardware/software ? Or is it likely that the cable and distances will
    not be suitable ?
    
    Any inputs may be useful to help us guide and influence the customer in
    this work.
    
    In this instance the customer MAY be able to instal FDDI with repeaters
    every 2km installed at their various "outlets"/locations between the
    sites.
    
    Thanks in advance
    
    Rog
    
    

    The only way the customer will be able to go that distance without
    "repeaters" along the way is by using Single Mode Fiber. I don't
    believe this type of fiber could be used by any of the Ethernet-based
    products so they would need to install it "dark". The SMF fiber
    support should be available before the CLusters-over-FDDI support so
    depending on their timeframe for installation, they may just want to
    wait.
    
    Debbie
    

The use of repeaters is almost certainly a bad idea.  Depending on precisely
what you mean by "repeater" it may not work at all, or it may work some
of the time but be very unreliable.

	paul