Conference 7.286::fddi

1343.0. "DECconcentrator 900MX and SMF RESTRICTION" by DELNI::ONEILL () Wed May 25 1994 08:33

	DECconcentrator 900MX and Single Mode Fiber Modular PMDs

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	* This notice is intended for customers that have ordered *
	* DECconcentrator 900MX (DEF6*-MA) and Single Mode Fiber  *
	* modular PMDs (DEFXS-AA).                                *
	***********************************************************

Contact: Michelle Bigelow, DTN 226-5168

There currently exists a problem that restricts configuring Single 
Mode Fiber (SMF) modular PMDs (modPMDs).  DEFXS-AA is a product supported
on multiple FDDI products.  The goal is to support up to six DEFXS per 
DECconcentrator 900MX.  However there is a restriction with the current 
version of DEFXS.  

DEFXS has a large fiber optic loop of cable which is made of glass.  
When configuring it in the concentrator, there is a problem when 
reinserting module back into concentrator enclosure.  The loop 
of cable bends.  If you exceed the bend radius, the cable breaks.

The DEFXS-AA is an orderable part number since it is supported on several 
products.  HOWEVER, it is NOT recommended that this is installed in the 
field.  It is ALSO RECOMMENDED that only ONE DEFXS be configured 
per concentrator and that the adjacent modPMD slot is left empty.  
Preconfigured options are available for ordering SMF support - 
DEF6A-MA and DEF6B-MA.

A new design to the SMF modPMD will be available end of Q1FY95 which 
will allow concentrator modules to be configured in the field with 
DEFXS modules in any modPMD slot (DEFXS-BA).

Order information for preconfigured options:

   Part				Description		       U.S. List
   Number							Price
o  DEF6A-MA       DEF6X-MA with four Multimode Fiber Optic	$8990
		  modPMDs (DEFXM-AA) in ports 3-6 and one 
		  Single Mode Fiber Optic modPMD (DEFXS-AA) 
		  in port 1 (port A or M).  Port 2 is empty.
o  DEF6B-MA       DEF6X-MA with four Multimode Fiber Optic	$8990
		  modPMDs (DEFXM-AA) in ports 1-4 and one 
		  Single Mode Fiber Optic modPMD (DEFXS-AA)
		  in port 6 (port B or M). Port 2 is empty.




Please note that the customer can order the Multimode Fiber Optic (MMF) 
modPMDS (DEFXM-AA) and Unshielded Twisted Pair (UTP) modPMDs (DEFXU-AA) 
and have trained personnel install these in the DEF6X-MA concentrator 
module.  There are no restrictions to number or slot configured in.