Conference 7.286::fddi

    Three DVN Sessions contained information on FDDI and Fiber networks.
    
    1. Fiber Optics Technology - DVN #112	
    2. Chipcom Ornet Design    - DVN #121
    3. FDDI Technology         - DVN #127
    
    Contact Ellen Spears (DTN 249-4458) to obtain copies of these DVN's.
    (Your cost center will be charged about $140 for all three tapes.)
                                                                     
    I understand that funding has been made available to condense the
    presentations into an FDDI Self Paced Course on Video Tape and will
    include a workbook. The target for release is Jan, 1990, and a pointer
    will be posted here when it is available.
    

    Could additional pointers be included to the multitude of reports
    and articles written by Digital employees regarding FDDI and fiber
    networks?

    Jim Kuenzel, Anand Parikh and James Marsh recently published an
    article "FDDI Dual Ring of Trees Topology" in Telecommunications
    Magazine. Since these people are Digital employees, is there a way
    this article could be accessed on-line?
    
    I don't want to sound like I complaining but my best source of Digital
    information are the trade magazines. I have no way of determining
    what information I miss because I don't have the "right" subscription.
    

    
    RE .1
    
    Any further info on the availability of the FDDI self paced course?
    
    Also,  how about a pointer to a location of the FDDI standard (either
    hardcopy or electronic)?  I looked quickly in this conference and
    didn't notice it anywhere, my apologies if I missed it.
    
    Thanks,
    
    -rob 

    All FDDI specifications are available from:
    
    GLOBAL Engineering (Irvine CA)
    800 854 7179
    
    PMD:	$25.00
    PHY:	$47.75
    MAC:	$41.00
    SMT:	$35.00
    
    I found this info published in the 9/14/89 issue of EDN.
    
    Does anyone know where internal to DEC I might get copies of these
    specifications or should I order them myself?
    
    -rob

    Keep in mind that SMT is a draft, and is a state of GREAT flux.
    
    	paul

From:	VLNVAX::ERLANG::JAIN "Raj Jain, LKG1-2/A19, DTN: 226-7642  12-Jan-1990 2106" 13-JAN-1990 12:59:47.71
To:	@REPORT1,@REPORT2,@REPORT3,@REPORT4
CC:	
Subj:	Technical Report on FDDI performance (DEC-TR-655) Available

The following DEC technical  report  is  now  available  for  internal  and
external distribution.

DEC-TR-655: Performance Analysis of FDDI Token Ring  Networks:   Effect  of
            Parameters and Guidelines for Setting TTRT
            14 pages.

The report is available in PostScript on:
                   FILES::NET$ARCH:[PAPERS]FDDI_PERF.PS

If you would like to receive a hard copy, please reply to this message with
your NAME and MAIL STOP.

If you want a soft copy mailed to you please include the word  PS  in  your
reply.

Any other words or sentences in the reply will only delay the delivery.


A detailed abstract of the report is as follows:


                                DEC-TR-655
             Performance Analysis of FDDI Token Ring Networks:
           Effect of Parameters and Guidelines for Setting TTRT
                                by Raj Jain

Fiber-Distributed Data Interface (FDDI) is a 100-Mbps  Local  Area  Network
(LAN) standard being developed by the American National Standards Institute
(ANSI).  It uses a timed-token access method and allows up to 500  stations
to be connected with a total fiber length of 200 kms.

We analyze the performance of FDDI using a simple analytical  model  and  a
simulation  model.   The  performance metrics of response time, efficiency,
and maximum access delay are considered.  The efficiency is defined as  the
ratio  of  maximum  obtainable  throughput  to the nominal bandwidth of the
network.  The access delay is defined as the time it  takes  to  receive  a
usable token.

The performance of FDDI  depends  upon  several  workload  parameters;  for
example;  the  arrival  pattern,  frame size, and configuration parameters,
such as the number of stations on the ring, extent of the ring, and  number
of  stations that are waiting to transmit.  In addition, the performance is
affected by a parameter called the Target Token Rotation Time ({bf  TTRT}),
which  can  be controlled by the network manager.  We considered the effect
of TTRT on various performance metrics for different  ring  configurations,
and  concluded that a TTRT value of 8 ms provides a good performance over a
wide range of configurations and workloads.

    "To obtain more details on ordering by electronic mail, send a message
    with the word "help" in the Subject line; you will receive detailed
    instructions."
    

    Re: 12.6 and the follow ons:   Please don't put requests for copies
    of that report here.  That was a mail message which I posted as a
    pointer for those interested.  Contact Raj Jain directly for copies
    of the report.  The comment about replying to the message referred to
    the original mail message, not the note.

Thanks to Funding from GIA Marketing, tapes of the FDDI Field Test Training
Seminar given in Littleton, MA the week of 12 February are now orderable via
the AVCATALOG infobase on VTX.

CID# 001767 	Title: FDDI Field Test Training 	Cost: ~$125

    The following FDDI Documentation is orderable from P&CS in Northboro.
    
    EK-DEFEB-IN		DECbridge500 Installation Guide
    
    EK-DEFCN-IN		DECconcentrator 500 Installation Guide
    EK-DEFCN-OP		DECconcentrator 500 Option Installation Guide
    
    EK-DFSLD-SD		FDDI System Level Description
    
    The best way to order these documents is to use VTX LOS.
    
    Bryan