Conference 7.286::fddi

1. FDDI operates by definition at a speed of 125 Megabaud (100 Mbits/s), which
   is different from the T3 speed.
   There are routers or similar devices that have FDDI and T3 ports, but that's
   different from "transmitting FDDI at T3 speed".

2. That depends.  If the protocol/implementation allows two LAN adapters on
   the same LAN, then yes; otherwise no.  The equivalent question  you could
   ask instead: does the file server allow two Ethernet adapters, connected
   to the same Ethernet?

	paul

Are there plans to make a DAS controller for XMI, Turbo Channel etc. 
The requirement is to provide "dual homing" capabilities, from a DECstation or
Large system.  I beleive that Question 2 in .0, is realy asking for this 
feature, which cannot achive with a SAS device.


John Layland

RE .0 & .1

What I'm looking for is a device that wouls have an FDDI card on one side and 
a T3 card on the other side.  Someting like a VITALINK TRANSlan bridge but
built for FDDI and that would use a T3 link to establish the extended LAN.

Andre
BTW: Thanks for the timely answers.

    
    Hi,
    
    You need to look at PROTEON GABROUTER,( CNX500 ).  They are the only 
    current implementor of FDDI in a GABROUTER.  ( A GABROUTER is a combination
    GATEWAY, BRIDGE, and ROUTER all rolled into one box. )  PROTEON
    has plans to include T3 capabuilities, but I don't have a time frame.
    We have a site that is using a PROTEON to ETHERNET to FDDI to TOKEN
    RING to T1.  
    
    Hope this helps,
    
    Randy
    

    Andre,
       Check with Terry Robinson, GIGAswitch product management for what
    we're doing for this type of solution (unannounced so it can't be
    discussed here). Depending on the timeframe you're looking at, this
    might be a solution. Also, I believe the DECNIS will have this
    capability in a future release.
    
    But as Paul said, these devices are FDDI-to-T3 routers/bridges, not
    FDDI on top of T3.
    
    Debbie
    

Exactly what I'm looking for.... not FDDI on T3 but from FDDI to T3....

Sorry.... my English suffers sometimes.... you see... I'm french sooooooooooo.

Thanks a million 
Andre!

Andr�,

Depending on what PID you are thinking of I would caution you to PROMISE
anything to your customer. After the FY92 result MANY groups in Digital
are reevaluating plans of the past.
 
As Debbie said the BIG question is WHEN your customer need this solution.

If it is during 1993 we may provide solution with a DEC product...

	For DECNIS check with Mike DELNI::Gayowski

IF customer insists on a solution NOW -

	NSC/Vitalink claim to have a solution - don't know how well
	it works, (but I think the FDDI/clusters people gave up on it.)
	It probably depends on what protocols you need to cross T3.
	This might however be available through NWSS/DECsite...

	CNX500 has as far as I know not yet a TE/E3 interface and the
	CNX runs out of steam around 20000 packet per second. Is that
	enough to fill a T3/E3 ? YES it is - if it is not doing too much else.

and to .4 I would like to say that I don't see what WE call GATEWAY (x.25 or
SNA) in the Proteon product. THey also say only Bridge/router in flyers.

Bon Chance !

	Torbjorn

PS,
	For DAS FDDI cards - mail Sharon DELNI::Oneill or Karl DELNI::Pieper
	Not probable for XMI though...

re: .8

>	NSC/Vitalink claim to have a solution - don't know how well
>	it works, (but I think the FDDI/clusters people gave up on it.)
>	It probably depends on what protocols you need to cross T3.

Yes, they have a product shipping today (the 6400 & 6800).

It must be pointed out that the 6400/6800 *encapsulates* protocols it
doesn't understand (like the VAXcluster protocol, SCS).  So it
doesn't work well (today) for clusters - and that's why the 
FDDI/cluster people gave up on it.

However, it will probably work just fine if you're using TCP/IP or DECnet.

Andre,

UNANNOUNCED & HENCE UNCOMMITTED

For DECNIS 600 we plan to reference sell a DSU product that will allow
the router to operate over T3 and E3 services.  The NIS organisation
will also handle the product.  This uses the FDDI interface as a
private connection method between the DSU and the router.  The same
DSU will be offered by the clusters group for extending FDDI
clustering over T3.  An important caveat is that the FDDI-T3 interface
is not a bridge in the Vitalink style, but more like a repeater that
passes all packets blindly.  In practice it only forwards the data
packets not the SMT.  Used with the router it will route and bridge
from other FDDI, or NI ports as well as from the other wide area
connections.  It may be just what you need but it depends very much on
what you are trying to achieve.

DELNI::GAYOWSKI  (MIKE)  is the NaC marketing contact and
SCHOOL::MAJIKAS  (DENIS) is the HAS contact

Regards
Jim

WILL THESE WORK?  I'm trying to configure a redundant configuration for
a customer and I'm having real problems with dual-homing and failover of
DECnet from one controllor to an other.  Please help.

CASE A
------
       +--------+               +----------+
=======| FDDI   |===============| CONC 500 |============
       | Bridge |               +----------+
       | 620    |                     |
       +--------+                     |
         |  |  |                      |
 802.3 links|  |      +-------+       |
            |         | WS    |       |
        +---+---+ Enet| FDDI  |       |
        | DEMPR |-----+  &    +-------+
        +-------+     | ENET  | SAS connection
                      |       |
                      +-------+

- Can I configure a station in this way?  
- Will I be able to use the FDDI SAS card as my primary network connection 
  with a fail over to the Ethernet card in case the FDDI controllor or 
  concentrator would go down.
- If I can't, what are my alternatives or what is faulty in the design?  What 
  should I change to gain failover capability?
- If I can failover, will it be automatic? Who does the failover, the protocol
  (DECnet,TCP/IP) or the hardware?

CASE B
------
       +----------+               +----------+
=======| CONC 500 |===============| CONC 500 |============
       +----------+               +----------+
            |                         |
            |                         |
            |                         |
            |         +-------------+ |
            |         | WS          | |
            |         | SAS card #1 +-+
            |         |  &          |
            +---------+ SAS card #2 | 
                      +-------------+

- Can the WS in case B use a failover mecanisim to assure communication to the 
  FDDI ring?

- Will dual homing provide for the loop, in my mind dual homing works only
  with DAS cards.


Andre Courchesne
BTW..... Boy! configuring FT solutions can be hard!

    re: .11
    
    Looking at Case B:  I don't believe SMT prevents that configuration,
    but it would be the responsibility of the drivers and/or network
    operating systems on the host to support the redundancy that you're
    looking for.  A good example is a Novell NetWare server, where the IPX
    protocol stack doesn't allow two or more controllers (regardless of the
    media type) to be bound to IPX and exist on the same physical network at
    the same time.
    
       - Larry
    

Cases A and B are functionally equivalent.  In both, you have two separate
data link entities.  Neither of them uses "dual homing" in the FDDI sense
of the word.  (Dual homing is a physical layer feature, not a data link layer
feature.)

Both cases are analogous to a dual Ethernet configuration; whether and how
that works depends on the higher layer protocols.  Yes, it is the 
responsibility of the higher layer protocols (typically the network layer, 
a.k.a. routing layer) to sort this out.

	paul

Hi,

This tentative design is what I would like to see for rendundant purposes will it work?


	      +--------------+              +--------------+
	======| Concentrator |==============| Concentrator |========     Application
	      +---------+----+              +-+---------+--+             Processors
		|	|		      |		|
		|	|	+-------------+		|			|
		|	|	|			|			|
		|	+-------|---------------+	|			|
		|		|		|	|			|
		|		|		|	|			|
		|	+-------+--+      +-----+----+  |			|
		+-------|  Server  |======|  Server  |--+    SCADA servers	|
			+-+----+---+ DSSI +-+---+----+				|
			  |    |	    |	|				|
			  |    |	    |	|				|
			  |    |	    |	|			+-------+-------+
			  |    |	    |	|			| X.25 Router   |
	--------+---------+----|------------+---|---------------	+-------+-------+		
		|	       |		|				|
		|	       |		|				|
	----+---|--------------+----------------+---------------		|
	    |	|								|
	    |	|								|
	+---+---+----+								|
	|   DECNIS   |								|
	+--++++++++--+								|
	   ||||||||								|
	   |||||||| <---- dedicated lines					|
		|								|
		|								|
		|								|
	    +---+------+-----------------------------------------x.25 private --+
	    |Real time |
	    |Polling   |
	    |Device    |
	    +----------+



Let me explain and chances are that you will steer me in the right direction.

The customer will provide about 250 dedicated lines to be use in a SACDA system.
I plan on connecting those lines in a DECNIS. In order to meet the redundant 
requirements each DECNIS should be conected to a dual rail ethernet, this will also
isolate the traffic of those dedicated lines to the SCADA server. Again for the pupose
of redundancy the SCADA sever is double. In any case, the active SCADA server will 
in turn provide services to application processors that will have a direct or indirect
connection to the ring. 

The protocols that will be use on this network will be DECnet phase IV and V, X.25 and
TCP/IP. Specifically the SCADA server will communicate with the real time device using
OSI over X.25. If the dedicated line fails the private X.25 network they have will be 
use for backup.

Marc
P.S. If anyone care you can call me my DTN is 632-3723. This I admit is not easy to
sumarize!!!! 

I will be able to fax a complete picture of this proposed configuration to anyone that 
can help.

Thanks a thousand times...