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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

1355.0. "MAC parameters thru SMT" by CAATS::VINES () Wed Jun 01 1994 18:32

    I'm trying to create a table of MAC parameters specified through SMT.
    
    I would like confirmation of the values that are already input, and any
    contributions to the blank spots would be appreciated.
    
    
    		MAC Parameters Specified Through SMT.
    
    ITEM	DESCRIPTION		BASE		DEFAULT VALUE
    
    1	Individual_MAC_address(16bit)	  O		xxxxxx
    
    2	Individual_MAC_address(48bit)	  O		xxxxxx
    
    3	group_MAC_address		  O		xxxxxx
    
    4	T_Min_value			  M		<4.0ms
    
    5	T_Max_value			  M		>165ms                               
       
    6	TVX_value			  M		2.35ms
    
    7	T_Req_value			  M		>T_Min <T_Max
    
    8	T_Neg_value			  M		8ms
    
    9	T_Pri_value			  M		??
    
    10	Indicate_for_own_frame		  M		??
    
    11	Indicate_for_rcv_only_good_frame  M		??
    
    
    
    Thanks 
    
    
    Phil.
    
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1355.1KONING::KONINGPaul Koning, B-16504Wed Jun 01 1994 18:4536
I'm trying to figure out what you used to create that list, or what you
would do with it afterwards.  The format looks a bit like a PICS, but
it doesn't look like a valid or meaningful PICS.

Anyway, the answers are:

    1	Individual_MAC_address(16bit)	  O		NOT SUPPORTED
    
    2	Individual_MAC_address(48bit)	  O		from address ROM
    
    3	group_MAC_address		  O		supplied by application
    
    4	T_Min_value			  M		fixed 4 ms
    
    5	T_Max_value			  M		fixed 167.77224 ms
       
    6	TVX_value			  M		set by mgmt, def=2.62 ms
    
    7	T_Req_value			  M		set by mgmt, def=8 ms
    
    8	T_Neg_value			  M		computed by MAC
    
    9	T_Pri_value			  M		NOT SUPPORTED
NOTE: that can't be "M"; it's clearly labelled in the standard as optional.
    
    10	Indicate_for_own_frame		  M		huh?
    
    11	Indicate_for_rcv_only_good_frame  M		huh?

Re the last two: normal drivers only deliver good frames, and not own frames.
The MAC chip can be put into a mode where it does receive own frames, but this
is for loopback testing only.  The hardware delivers bad frames along with
good ones; it's the driver that discards the bad ones (and counts them).

	paul
  
1355.2CAATS::VINESThu Jun 02 1994 15:378
    Thanks for the info Paul.
    
    Actually, the data in note .0 originated from a third party voice
    switch that will reside on the LAN. I want to make some comparatives
    between DEC's and its SMT parameters to see if there are any
    differences, between them.
    
    Phil
1355.3KONING::KONINGPaul Koning, B-16504Thu Jun 02 1994 18:234
I'm still puzzled.  If you find differences, what conclusions would you
draw from them?

	paul