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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

1935.0. "DEFEA - TCP/IP-performance problem" by NBOFS1::JAKOB () Fri Jan 26 1996 07:38

    
    
      Hallo,
    
      my customer has tho following configuration:
    
    
      He has 4 NT-Server (COMPAQ Proliant 4000) with FDDI-cards DEFEA-UB.
    
      TCP/IP on this FDDI-lines will take about 10 times longer as on
      the normal ethernet-interface.
    
      What can it be?
    
    
      Thanks
    
      Herbert
    
    
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1935.1NETCAD::STEFANIMachines to humanizeFri Jan 26 1996 13:5113
    >>  TCP/IP on this FDDI-lines will take about 10 times longer as on
    >>  the normal ethernet-interface.
    
    This hasn't been our experience here.  We're able to get DEFEA's to do
    40Mbps point-to-point on Alpha servers.  Even on an Intel-based system,
    I'm sure we'll do over 10Mbps (standard Ethernet).
    
    Check the Windows NT Notes conference (DECWET::WINDOWS-NT) for
    information on tuning the TCP/IP stack.  You might need to increase the
    message size to let TCP/IP know that it can send more packets to the
    driver during transmit.
    
    -Larry
1935.2IP addressing? Stress tests?NETCAD::ROLKEIce of DamocleseMon Jan 29 1996 15:1119
>      my customer has tho following configuration:
>    
>    
>      He has 4 NT-Server (COMPAQ Proliant 4000) with FDDI-cards DEFEA-UB.
>    
>      TCP/IP on this FDDI-lines will take about 10 times longer as on
>      the normal ethernet-interface.
>    

What is the customer's IP configuration?  It is easy enough to misconfigure
IP addresses so that all your traffic goes through a router and performance
drops.  Make sure that the servers and clients are on the same subnet over
FDDI.  

Also, nobody is running any wicked traffic generators over FDDI, are they?
Someone else's stress test can make your FDDI connection look "bad" while
your ethernet connection looks "good".

Chuck