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Conference netcad::hub_mgnt

Title:DEChub/HUBwatch/PROBEwatch CONFERENCE
Notice:Firmware -2, Doc -3, Power -4, HW kits -5, firm load -6&7
Moderator:NETCAD::COLELLADT
Created:Wed Nov 13 1991
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:4455
Total number of notes:16761

260.0. "Config Rules: My Network config OK ???" by HGOVC::GUPTA () Fri Jun 04 1993 03:11

We are proposing the following network configuration to Shell Oil Hong Kong
where 3xDEChub90 will be connected to 2xUBhubs. Can anyone have a look at the
following configuration and suggest if there are any rule violations etc ? There
will one set of Server with Primary Link to DEChub #1 and secondary link to
UB#1 (connected to 90T and ASM 324). Another set of Server will have Primary
link to UBhub and secondary to DEChub in a Fault Tolerant configuration. 

	,----------------,
	|3xASM 100 (T/S) |   UB HUB #2
	+----------------+
  ,-----|ASM500 (NETCARD)|            		LEGEND
  |	+----------------+
  |	|4xASM 310(UTP)  |                         ------   PRIMARY LINK
  |	+----------------+                         ......   BACKUP LINK
  |	|ASM 6300 (R/B)  |----> (R/B)                                          
  |	+----------------+                                            
  |	|ASM 700 (SUP)	 |.................................................,
  |	`----------------'                                                 .
  | (F/O CABLE)                                 ,---------------,          .
  |     ,---------------,                       |               |..........'
  |     |4x90T (UTP)	|   DEC HUB    ,--------|ASM 324T2 (UTP)|..........,
  |	+---------------+     #1       |	+---------------+          .
  |	|90B (BRIDGE)	|--------------'	|2xASM100(T/S)	|  UB HUB  .
  |	+---------------+			+---------------+   #1     .
  `-----|90FL (FO/C)	|		   ,----|ASM 700 (SUP)	|          .
  ,-----|		|		   |	+---------------+          .
  |	+---------------+		   |	|ASM 6300 (R/B) |--->T1    .
  |	|90T (UTP)	|...........,	   |	`---------------'          .
  |	`---------------'	    .	   |	                           .
  |                                 .      |                               .
  |                                 .      |                               .
  |	,---------------,           .      |                               .
  |	|90B (BRIDGE)	|...........'      |                               .
  |	+---------------+                  |                               .
  |	|4x90T (UTP)	|   DEC HUB #2     |                               .
  |	+---------------+                  |                               .
  |	|90FA (FO REPTR)|------------------'                               .
  |	`---------------'                                                  .
  |                                                                        .
  |	,---------------,                                                  .
  |	|90A (DECagent)	|   DEC HUB #3		                           .
  |	+---------------+                                                  .
  |	|90B (BRIDGE)	|..................................................'
  |	+---------------+
  `-----|90FA (FO REPTR)|
	+---------------+
	|3x90T (UTP)	|
	`---------------'


As per information from Shell Oil/UB, ASM 500 is just a network interface card
which works with ASM 700 card and provide fault-tolerance.

Any help/feedback/improvements willbe highly appreciated.

Thanks,
Surender Gupta/Hong Kong Office
T.RTitleUserPersonal
Name
DateLines
260.1How about tying two hubs together?EMDS::SEAVERBill Seaver, HUBwatch MktgMon Jun 14 1993 02:023
    you could tie two of the three hubs together and eliminate a bridge if
    they are close enough.
    
260.2Some guesses.CGOS01::DMARLOWEdsk dsk dsk (tsk tsk tsk)Mon Jun 14 1993 16:1825
It looks like it could work depending on how the ASM 700 switch
links for redundancy.  But there is a greater problem waiting to
happen and that has to do with address table space in the DECbridge
90.
    
The DECbridge 90 in Hub #1 sees the following ports:
DEChub #1	5 x 90T = 40 ports
DEChub #3	3 x 90T = 24 ports
UB Hub #2	4 x 12? = 48 ports
UB Hub #2 3 T/S     =  3 addresses
UB Hub #3 2 T/S     =  2 addresses
                    ----------------
            Total    117 addresses

If for some reason DEChub #2 gets added in due to alternate link switching
then you can add another 36 addresses for a total of 153 addresses seen by
the DB90 in hub #1.  Still below the 200 but if some fault brings UB Hub #1
under the above DB90 then you may see 200+ addresses on that bridge.  Not 
knowning how the UB redundancy works, is there a better way to redo this 
whole thing so there is less unknowns, especially if a path fails?  Also do 
the UB modules understand spanning tree or are you completely relying on 
the DB90 to keep things straight?

dave
    
260.3One of the three DB90 HAS TO BE activeHGOVC::GUPTAWed Jun 16 1993 10:4334
    Thanks Dave for your input.
    
    I understand that I am not very comfortable regarding 200 station
    limitation. But I am planning for AT LEAST ONE DB90 to be active at any
    given point of time. This is essential for all the HUBS (DEC & UB) to
    be reachable all the time. The logical network topology attempts to
    divide the network into two LAN segments connected by one DB90. At the
    same time, the attempt is to provide at least one more redundent path
    (repeater or DB 90) to each HUB (DEC & UB). With at least one active
    DB90, I am likely to have around 110 addresses (as you have calculated)
    which I thought was safe. With this requirement of one active and one
    redundent path to each HUB, I could not think of any other way of
    simplifying the network topology. Any bright ideas ?
    
    As for the UB hubs, Shell (the customer) tells me that ASM 500 & 700
    (UB HUB #2) are just network cards and are backup for each other. These
    cards exchange control info on the internal control bus and in case
    ASM500 goes down, ASM700 takes over. 
    
    There are NO bridges in UB hubs which will take part in the Spanning
    Tree. Yes, I EXPECT and RELY COMPLETELY on DB90 to keep things
    straight.
    
    Hence, I will need your help in this configuration. Do you see any
    problems with this configuration ? Any improvements ? 
    
    Thanks for your help.
    
    Reply to .1 (Bill Seaver),
    		The two DEChubs cannot be tied together because they all
    		are on different floors.
     
    Regards,                                              
    Surender   
260.4Redraw.CGOS01::DMARLOWEdsk dsk dsk (tsk tsk tsk)Thu Jun 17 1993 14:2750
    What about....
    
	|   -----------------
	|   |DB90|90T|      |                 |
	|---|    |   |      | DEChub          |  some sort of main backbone
	|   |    |   |      |
	|   -----------------                 +
	|          +                          +  UTP interconnects
	|          +
	|    ----------------
	|    |   |UTP|      |
	|----|   |   |      |
	|    |   |   |      |
	|    ----------------
	|          +
	|          +
	|   -----------------
	|   |DB90|90T|      |
	|---|    |   |      | DEChub
	|   |    |   |      |
	|   -----------------
	|
	|
	|    ----------------
	|    |   |UTP|      |
	|----|   |   |      | UBhub
	|    |   |   |      |
	|    ----------------
	|          +
	|          +
	|   -----------------
	|   |DB90|90T|      |
	|---|    |   |      | DEChub
	|   |    |   |      |
	|   -----------------
	|

In this case all DECbridge 90s will be in standby mode.  Any failure of any 
card or UTP link will cause one of the bridges to become active.  You should 
not have an address limitation problem because when a failure occurs, one 
or more hubs will appear on the backbone side of the DECbridge and not
on the work group side.

Also I make sure the UTP interconnecting the hubs is not subject to
electrical noise.  Keep the install as clean as possible.

Just a thought.

Dave