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Cheryle,
No, you can't connect DECstations together without using the
DECconcentrator 500. There are a number of reasons for this,
one being the DECconcentrator is designed to provide connectivity
between FDDI systems & bridges, and stations on the dual FDDI ring,
or stations on other concentrators on the FDDI ring. There are others
reasons which we can discuss when we speak.
Bottom line, Digital's FDDI controllers and Bridges are Single
Attachment Station (SAS) implementations and requires the DECconcentrator
for connectivity.
The DECbridge 500 is designed to provide connectivity between Ethernet
components and FDDI components, or Ethernet segments using FDDI as the
transport medium.
Give me a call at your earliest convenience..
Later,
Ray
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All of Digital's current FDDI devices are Single Attachment Stations
(SAS) except the Concentrator (which is a DAC). Our backplane
controllers and the brige all have a single FDDI "S" connector. The
Concentrator has an "A" port, and a "B" port, and 4 (or 8) "M" ports.
Notice, (as Paul' comment in 107.2 notes) that a slave port can connect
to anything, but it becomes intrinsically limited without the
concentrator. The chart below is taken verbatim from the FDDI System
Level Description Page 2-20.
NODE: This Node This Node This Node This Node
Port Type A B M S
(master) (slave)
Other Node A no yes(1) yes yes
Other Node B yes(2) no yes yes
Other Node M yes(3) yes(4) no yes
Other Node S yes yes yes yes
Rule 1: This Node's Port B can connect to Other Node's Port A IF AND
ONLY IF This Node's Port A is connected to Port B or S of
another station or disconnected.
Rule 2: This Node's Port A can connect to Other Node's Port B IF AND
ONLY IF This Node's Port B is connected to Port A or S of
another station or disconnected.
Rule 3: This Node's Port A can connect to Other Node's Port M IF AND
ONLY IF This Node's Port B is connected to Port A or S of
another station or disconnected. If This Node's Port B is
connected to PORT A of another station, it immediately will
disconnect when This Node Port A connects to Port M of
Other Node.
Rule 4: This Node's Port B can accept connection to Other Node's Port
M. If This Node's Port A is connected to Port B or M of
another station, it will immediately disconnect when This
Node's Port B connects to Port M of Other node.
Port A: Connects to the incoming primary ring and the secondary
outgoing ring of the FDDI Dual ring. Part of a (DAS) Dual
Attachment Station, or (DAC) Dual Attachment Concentrator.
Port B: Connects to the outgoing primary ring and the secondary
incoming ring of the FDDI Dual ring. Part of a (DAS) Dual
Attachment Station, or (DAC) Dual Attachment Concentrator.
Port M: Master Port, Connects a (CON) Concentrator to a SAS, DAS, or
another DAC. This port is only implemented in the CON.
Port S: Slave Port, Connects a SAS to a CON. Can also connect to
a DAS, or another SAS, but these configurations are not
recommended.
End of excerpt: Page 2-20 FDDI System Level Description (EK-DFSLD-SD)
JR
JR
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