Conference 7.286::fddi

	As mentioned in the announcement of FDDI, VAXclusters will (some day)
	be able to use that media as a cluster interconnect.  LAVc is rather
	an obsolete term for (pre-V5 of VMS) VAXclusters using the NI as its
	interconnect.  Since V5, a cluster is a cluster no mater what its
	interconnect.

	So, to answer the question... yes and no.  You will have Clusters
	on the FDDI but they probably will not be called Local Area VAXclusters.

		Bob L.

        
    I'm currently looking at the rewiring of a Digital building which will
    start to take place in the next couple of months. We are looking at the
    feasability of using an FDDI backbone. The building will contain a 
    large number of clusters, whose members will be distributed throught the 
    building. It is therefore essential that the networking option we 
    choose will support distributed clusters running old(V5.0-V5.3) and new 
    versions of VMS.
        
    Configuration 1
    
    All VAX'S are part of the same cluster. Therefore can clusters be 
    supported when the VAX'S are attached to ethernet but there is a FDDI 
    ring in between the ethernet segments. Is this configuration possible 
    and supported today?.

      +---+   +---+                +----+
      |VAX|   |VAX|                |VAX |
      +-+-+   +-+-+                +-+--+              
        +---+---+ ETHERNET           | ETHERNET
            |                        |           
      +-----+-------+         +------+------+          
      |10/100 Bridge|         |10/100 Bridge|
      +-----+-------+         +-----+-------+
            |                       |                 
            |FDDI                   | FDDI
         +--+-+    FDDI RING     +--+-+                    
         |CONC+------------------+CONC|                    
         +--+-+                  +-+--+                           
            |                      |                      
            +----------------------+                       
                   FDDI RING                                  
    
    Configuration 2
    
    All VAX'S are in the same cluster, but the VAX's are directly joined by 
    FDDI. I assume that this configuration will only be possible when VMS has
    be upgraded to support the FDDI adapters. 

            +---+                       +---+
            |VAX|                       |VAX|
            +-+-+                       +-+-+
              |                           |
         FDDI +------------+  +-----------+ FDDI
                           |  |
                         +-+--++
                         |CONC |
                         +-----+
    OR
            +---+                         +----+
            |VAX|                         |VAX |
            +-+-+        FDDI RING        +--+-+
              |      +-----------------+     |
              |      |                 |     |
              |   +--+-+            +--+-+   |
       FDDI   +---+CONC|            |CONC+---+  FDDI
                  +--+-+            +--+-+
                     |                 |
                     +-----------------+
    
	
	Thanks

	Gary

    I believe both configurations will be supported when VAXcluster support
    over FDDI is announced, but that won't be until early FY92 most likely.
    You might want to ask this in the VLAB::FDDI_CLUSTERS conference.
    
    Debbie
    

Since the first configuration involves only VAXen connected to the Ethernet,
it should be supported today.

	paul

VAXes on Ethernet with an FDDI backbone is supported today, and in fact my
satellite workstation connects to the rest of the cluster over an FDDI backbone
in MR01.  The SPD does limit the size and/or number of nodes which have only
Ethernet connections between them. 

Can you point me at the SPD or give me more details on this size and/or number
limit of the nodes which can have only ethernet connections between them

Thanks 

Gary

	The current VAXcluster SPD is V5.4 SPD # 29.78.04. 
You can get a copy of it through $VTX SPD.

	You can connect cluster nodes through FDDI bridges as long
as you follow the standard configuration rules. (ie. no more than 7
levels of bridges (FDDI+Ethernet combined)).

	True FDDI based clusters (ones with direct VAX connections)
may have distance length and number of stations allowed on the FDDI
ring restrictions. There will be more infomation on this in the next
few months as configuration guidelines are developed for FDDI based
clusters.

Joe

Re .6:

The relevant portion of the SPD is:

          o  A CI path is needed between any pair of the following CPUs in
             a VAXcluster system. An Ethernet only VAXcluster system may
             include a maximum of one of the following CPUs:

             -    VAX 6000-xxx
             -    VAX 85xx
             -    VAX 86xx
             -    VAX 8700
             -    VAX 88xx
             -    VAX 9xx

Undoubtedly the introduction of FDDI will mean this section of the SPD must be
updated.

.3>    You might want to ask this in the VLAB::FDDI_CLUSTERS conference.

For some time now, I have gotten "remote node not reachable" when I try to open
this conference.  Has the conference moved, or have it and its node both gone
away?

                       -< Whither VLAB::FDDI_CLUSTERS? >-

	Any FDDI VAXcluster discussions are on SPEZKO::CLUSTER. The 
VLAB::FDDI_CLUSTERS file was considered redundant and was deleted.

Joe

.10>	Any FDDI VAXcluster discussions are on SPEZKO::CLUSTER.  The
.10> VLAB::FDDI_CLUSTERS file was considered redundant and was deleted.

Thanks for the information.  This morning, interestingly, VLAB::FDDI_CLUSTERS
is back on line.  I guess that someone read .9 and decided to restore it.

VLAB:: is now only one node within the SCHOOL:: cluster alias.  You may have
better luck accessing conferences which were on VLAB:: on SCHOOL:: instead.