Conference 7.286::fddi

1. I'll assume you are talking about PMF (Parameter Management Frames).
   We don't allow PMF SETs and we don't have an RBMS-to-PMF or SNMP-to-PMF
   gateway.  So the answer is no.  We can't manage another device via
   PMFs.

2. Out-of-Band is a subset of the functions/attributes available via ELMS.

3. Yes.  LerCutoff is manageable via SNMP.  I'm not sure what the ELMS
   parameter name is (ler_threshold maybe.)

4. No.  The load is done via RBMS and MOP protocols.  NDU is the easy way.

5. SMT 7.1 :  that depends on the product.  You will have to talk to the
   product managers to see when they will build with the new version of SMT.
   We plan on having the SMT part done within 2 months.

6. Extended LCT : 50 sec link confidence test.  What did he want to know about?
   It is used when a connection is withhold (dual homed) or if the connection
   is off due to LEM cutoff.

7. No problem to dual home with anybody elses equipment that follow the spec.
   The only issue is what color the LED will flash.  We have seen some problems
   with that.  The LED is not flashing RED/GREEN on our boxes sometimes.  But
   the connection is withhold correctly.  Hope to fix this when SMT 7.1 comes
   out.

	Luc 

Referring to .1

> 2. Out-of-Band is a subset of the functions/attributes available via ELMS.
>
> 3. Yes.  LerCutoff is manageable via SNMP.  I'm not sure what the ELMS
>   parameter name is (ler_threshold maybe.)

	ELM AM/FM is really the way to manage the concentrator. Can he get 
	do LerCutoff via the Out-of_band port?

> 6. Extended LCT : 50 sec link confidence test.  What did he want to know about?
>    It is used when a connection is withhold (dual homed) or if the connection
>    is off due to LEM cutoff.

	He wanted to know if we implemented it in our concentrators and I
	guess the answer is yes. What is the relationship between "withold"
	and dual homing?

	The question he asked was "When his router is dual homed, does the
	concentrator automatically turn off one if its links ?"

	He is also planning to run OSPF routing. Have we enountered any
	problems with it?

Your response is very useful. Thanks.

Leslie.

	Yes you can manage LEM Threshold (which is LerCutoff) using OBM.

	The PHY is not turned OFF when dual homing.  It is withheld.
	It does an Extended LCT with it's neighbor and then restarts.
	If nothing changes, they will do this forever.

	OSPF routing:  SMT really doesn't care about specific LLC services
	(like routing).  There should be no problems with an type of
	routing.

	Luc

>	The PHY is not turned OFF when dual homing.  It is withheld.
>	It does an Extended LCT with it's neighbor and then restarts.
>	If nothing changes, they will do this forever.

	Please bear with me, I am afraid I am still a bit confused about 
	how dual homing is implemented.

	From .3, if a device is dual homed to two concentrators (Port A
	to conc 1, Port B to conc 2), which PHY on which port is going
	to be withheld? What is the purpose of the withholding?
	
	Would the concentrator know when a FDDI device is dual homed?

	Is this done automatically or does the concentrator have to be 
	configured?	

	Your information is much appreciated.

	Leslie.

    The device with the A/B ports is the one that recognizes the
    dual-homing configuration by noticing that it is connected to two M
    ports.  If both connections are error-free, then the DAS device will
    choose the B port to be active and withhold the A port.
    
    The withholding is done because the A/B device only needs one SAS
    connection to the ring.  There is only one MAC.  
    
    The concentrator doesn't particularly care whether the connected
    station is an A or B or S port, but will give you the information if
    you ask via network management.  No special configuration is needed.
    
    Regards,
    
    Steve

	The M port that is connected to a A port 'guesses' that the
	other end is dual homed.  "If I'm an M and the other end is
	an A and the other end withholds the connection and there were
	no errors (LCT for example) then I must be part of a dual homed 
	configuration and I'll flash RED/GREEN."

	This works fine with DEC products.  It may have problems with
	other vendors.  The connection will do the right thing but it
	may blink green for the first 50 seconds (which is the duration
	of an Extended LCT.)

	Luc	

    Hello,
    
    Does anyone know if the leds on the Deconcentrator 500 should blink green
    red in duel homed mode with a cisco.
    
    I have a situation where the green led only is blinking permanently &
    not just for the first 30 seconds.
    
    Is this expected behaviour with Cisco on Decconcentrator 500?
    
    Thanks for any help,
    
    Jon
    

	The M ports on the Concentrator have no way of knowing that they
	are part of a Dual Homing configuration.  What we do is:

		If we are an M port and our neighbor is an A port and
		PCM was going fine (LCT ok) but the remote connection
		rejected us before completion then we ASSUME that it was 
                rejected due to Dual Homing and we blink red/green.

	DEC products reject before doing an extended LCT (50 seconds)
	so that both ends (if DEC) blink red/green right away.  The standard
	says you are to do the extended LCT first and then reject (stupid!).
	So with other vendors you may see a 50 second delay where we will
	continue to blink green.

	If Cisco is doing something weird (it wouldn't be the first time)
	where they allow PCM to complete and then break the connection,
	and then start over, this would cause us to stay blinking green
	AND cause claims every 50 seconds on the ring (BAD).  We have a
	counter we keep for connections completed in our vendor MIB.
	You may want to look at this counter for the M port on the 
	Concentrator to see if it is moving.  And also watch ring inits.

	Luc