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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

888.0. "I.ve got a REALLY big performance problem here, please anybody could help ..." by ROMTSS::CERIOLI () Fri Mar 05 1993 11:01

I've a customer using DEFZA on ULTRIX DECsystem 5900, observing same
throughput as on ethernet.
I've posted note 872 getting 0 answers. Please read it for more details.
I've also read note 857 about DEFTA, and after a "conversation" on the 
ULTRIX notesfile, I've reached the conclusion that I need a high performance 
FDDI interface.
The question is:

Will the DEFTA be available on ULTRIX DECsystems 5900?
and
Will it be possible to observe a rate of at least 20/30 Mbit/sec for ftp file
transfer and nfs file service (DEFZA performs like ethernet, 3 to 5 Mbit/sec)?

We are planning to migrate the (2 to 5 M$ worth) customer to OSF AXP, but we 
need to demonstrate NOW this capability on FDDI, otherwise our credibility as 
DEC will be severely affected.

If this is not the right place to ask, please point me to the proper resource.

Thanks in advance for any help.

Andrea.
T.RTitleUserPersonal
Name		DateLines
888.1QUIVER::WASHABAUGHBorn to be MildFri Mar 05 1993 12:317
I'm not an ULTRIX expert, so I cannot help you solve your problem.  
However, although moving to a DEFTA is a good idea, I suspect that
whatever is keeping your performance low on the DEFZA (it should be
working much faster!) might also keep your performance low on the
DEFTA.

doug
888.2I agree, but ...ROMTSS::CERIOLIMon Mar 08 1993 03:5111
I agree, but hopefully moving to DEFTA will improve performances, just
because of the hardware, by a factor greater than 2, and this will suffice
to recover from this situation.

I need to know if what above is reasonable, and if DEFTA can be used on
a DECsystem 5900 running ULTRIX, regardless of whether this is supported
or not, since this is a temporary solution.

Thanks in advance.

Andrea
888.3The DEFZA can do better than ethernetSTKHLM::TORGNYMon Mar 08 1993 04:1436
    Hi,

    with the performance figures you quote for the DEFZA I doubt that it's
    the bottle neck. If not the DEFTA will not help. I don't know the 5900
    well enough to tell if it can be the reason, compared to my figures on
    the 5000/200.

    Regards,

    	Torgny...



          <<< NOTED::DISK$NOTES3:[NOTES$LIBRARY_3OF4]DNU_OSI.NOTE;1 >>>
                       -< DECnet/OSI for {ULTRIX,OSF/1} >-
================================================================================
Note 20.6                        What about FDDI                          6 of 8
STKHLM::TORGNY                                       16 lines  12-JUN-1991 12:08
                            -< TP4 faster than NSP >-
--------------------------------------------------------------------------------
	Hi,

For your reference, here is a summary of the transfer rates I've noticed
between two DECstation 5000/200, connected to a DECconcentrator 500. On all
the occasions the sender run out of cpu.


TCP/IP default		      				18 Mbps
UDP/IP default						20 Mbps
UDP/IP without checksum	      				34 Mbps

DECnet default						12 Mbps
DECnet SDU size 4357, segment buffer size 65535		14 Mbps
DECnet changed from NSP to OSI transport		17 Mbps
DECnet without congestion avoidance			19 Mbps
888.4Fixed, the bottleneck was not the FDDI, but the disk.ROMTSS::CERIOLIMon Mar 08 1993 12:228
Thanks for your answers.

yes, the bottleneck were the disks.
with task to task comm. I got the figures listed in .3

Ciao

Andrea.