| 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 | 
    Hi all,
    
    A project in my country involves a campus backbone, with VAX 7600 and
    VAX 4500 serving 120 PC clients. Each PC client runs eXcursion for
    Windows (X application). They want to access the VAX 7610 application,
    some in text mode, some in graphics mode.
    
    We proposed a FDDI solution, while FiberMUX proposed a TDM-based hub,
    offering 100 Mbps bandwidth (split for voice and data).
    
    1. Is our design "overkill"? Is a switched Ethernet Hub (such as
       DEChub 900) sufficient?
    2. What advantages do we have over TDM-based solution from FiberMux?
    
    FYI, the VAX 7610 in the future might become a server for another
    applications; or, the number of VAXes might increase if they have
    enough funding. Or, AXPs...
    
    Thanks for any advice.
    
    Best Regards,
    Fung Siong - Indonesia
| T.R | Title | User | Personal Name | Date | Lines | 
|---|---|---|---|---|---|
| 948.1 | FDDI may be overkill | JUMP4::JOY | Perception is reality | Wed May 12 1993 12:23 | 22 | 
|     Siong,
       I'm assuming the 120 PCs will reside on Ethernet with the servers
    sitting on FDDI? Most likely a switched Ethernet will do the trick for
    now. THe beauty of the the DEChub is that you can add FDDI to it later
    if need be and migrate the servers and perhaps some of the PCs to the
    FDDI ring. When the per-port switching capability is available for the
    DECrepeater 900, you will be able to isolate groups of Ethernet users
    to particular LANs to improve performance before needing to upgrade to
    FDDI as well. And, with an ATM card being planned for the DEChub in the
    future, you can show them a growth path for both their voice and data
    which Fibermux can't really give them with the TDM. THey will protect
    their investment in the DEChub backplane and be able to grow their
    bandwidth requirements gradually as needed. 
    
    I would probably look quite intently at the DEChub solution. And
    somewhere there is a number of how many Gbps capacity the backplane has
    (can someone help me out with the number?), so it will give them much
    more growth than the 50Mbps for each data and voice that FIbermux
    offers.
    
    Debbie
    
 | |||||