Conference 7.286::fddi

133.0. "HOW MANY NODES IN FDDI???" by ASHLND::KULL () Tue Sep 04 1990 17:21

    I need to know the max number of nodes in a FDDI LAN?
    
    The NBG states
    
    Maximum number of concentrators in a dual-ring of trees structure is 
    limited by the number of devices that can connnect to the LAN.  ANSI
    specifies no more than 1,000 connections (500 devices) on on e FDDI
    LAN.   The number of conectors is determined by the number of ports
    used.  Each concentrator counts as one device.  
    
    The FDDI System Level Descriptions states on page 1-26
    
    Physical Connections	500
    
    In Jim Kuenzel's FDDI  Tutorial from DECUS 1989  page 346;
    
    o Maximum Number of MAC's (M_Max) 1000
    
    " "  page 347
    
    o 1000 Physical Connections
    
    In Raj Jain's Introduction to FDDI Aug 17, 1989 page 5;
    
    500 Stations (1000 Attachments)
    
    Moreover, there seems to be multiple definitions of what is a NODE and 
    what is a STATION.  Per the Description, a Node is;
    
    A generic term applying to any FDDI network attachment (station,
    concentrator, or bridge).  
    
    
    So, what I need is a simple definition of how many of the various FDDI
    nodes can be attached to a single FDDI LAN.  Like in the format of;
    
    DAC counts as ???
    SAC counts as ???
    
    Bridge counts as ???
    
    SAS counts as ???
    DAS counts as ???
    
    Total of which can not exceed ???
    
    
    I need this for DECwrite Intro to FDDI I am writing.  It contains lots
    of diagrams.  A preliminary copy can be found in 
    ASHLND::SYS$PUBLIC:FDDI-INTRO.DOC  
    
    
    
    
    
    

    DAC counts as 1
    SAC counts as 1
    
    Bridge counts as 1
    
    SAS counts as 1
    DAS counts as 1
    
    Total of which can not exceed 500
    

Incidentally, a bridge IS a SAS.  (Well, it's a station; it can be a DAS or
a SAS.  Ours is a SAS.)

	paul

    I read in various Digital articles that the maximum number of stations
    for FDDI is 100. What is the reason for this while the standard
    specifies 1000 ports?
    
    Why is the maximum 1000 ports (technical point of view)? 
    
    
    Lodewijk (who's giving some FDDI training)
                                                            

    I thought it was 500 DAS stations (IE: the correlation of your
    reference to 1000 ports), with a max of 200 kilometers (124 miles),
    of fiber.
    
    Bob