| Title: | FDDI - The Next Generation | 
| Moderator: | NETCAD::STEFANI | 
| Created: | Thu Apr 27 1989 | 
| Last Modified: | Thu Jun 05 1997 | 
| Last Successful Update: | Fri Jun 06 1997 | 
| Number of topics: | 2259 | 
| Total number of notes: | 8590 | 
This note has also been posted in the CLUSTER conference.
We are assisting a customer to finalize a configuration to upgrade their 
existing cluster. The proposed configuration is as follows:
 
			|---12 disks--|
			|	      |
			|---sys disk--|
			|	      |
		 	 \____	_____/
			      SC
		 	  ____	_____
			 /     |     \
			/      |      \
		      6510    6510    8530..
                       ||      ||	   :
		    -------------------   connected to Ethernet segment
		    |  DEConcentrator |
		    |	   500        |
		    -------------------
		       ||   	   ||
		   DECbridge	DECbridge
		      610	  610
		  
		   :  :  :      :  :  :
	6 Ethernet segments with 24 VAXstation 3100 and 24 VAXstation 2000
	plus host based X-windows terminals, PCs.
All VAXs & VAXstations boot from the the same system disk. The VAXstations
have local page and swap disks. The VAXstations are running Interleaf (11 
concurrent), software development (LSE, ADA, PASCAL).
Problem:
They are currently running a single Ethenet segment and it is busy (40-50% 
average). 80% of the traffic is LAVC. The reasoning behind the the FDDI 
equipment is to increase the bandwidth available to access the main cluster. 
Questions:
(1) Our concern is the DECbridge 610 - will it be a bottleneck ?
(2) Does anyone have a similar environment? 
(3) What has been the experience with this configuration with respect to 
    performance?
Any other ideas would be welcome.
| T.R | Title | User | Personal Name | Date | Lines | 
|---|---|---|---|---|---|
| 546.1 | Shouldn't be a problem | JUMP4::JOY | Happy at last | Mon May 04 1992 11:53 | 14 | 
|     Leslie,
      If I understand you correctly, you are taking a single Ethernet
    segment and splitting it into 6 segments which you will then connect
    thru the 610s onto the FDDI ring. Your single Ethernet today is running
    around 40% utilization. Since each port on the DB610s can handle ~7Mbps
    and each of the 3 ports is bridged from the others and the FDDI side, I
    can't imagine how the DB610s could cause a bottleneck. The thruput of
    the bridges are around 122Mbps total, so I don't think you have
    anything to worry about insofar as the bridges being bottlenecks.
    
    Can't help with your other questions though.
    
    Debbie
    
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