Conference 7.286::fddi

    Bus speed means diddley squat.  It's sort of the MIPs in the ETHERNET
    bridge world.  It's the processing speed that counts.  How fast
    you can filter (decide if it needs to go on the ETHERNET) and forward
    (actually forward the packet).  
    
    The DB600 has 3 ETHERNETs all bridged from one another.  If you add
    the FDDI card it is also fully bridged.
    
    I was told that the throughput speed ie. forwarding to the 3 ETHERNET's,
    is not quite 30Mb/s.  It's something like 22Mb/s.  From what I
    understand is that this is the aggregate throughput.  This throughput
    is dynamically allocated as dictated by traffic flow. If 2 ETHERNET's
    run at 8Mb then the 3rd can get the remaining 6Mb.  That's not bad 
    considering most customer ETHERNET's only see 20% which is 2Mb. So in 
    real life that's only 6Mb of a possible 22Mb.
    
    I've had a customer looking at other vendors 10/100 bridges that
    go into a hub.  One of the better ones can forward some 7500 ETHERNET
    packets out of a possible 14,880.  The customer was also told that
    they will have translation (vs encapsulation) in the fall.  Not
    a very open solution.
    
    The other thing is how fast can they filter.  If they cannot filter
    at FDDI rates (up to 463,000 packets/s) then it's possible that
    an address that should be forwarded to the ETHERNET might get missed.
    That can put a strain on the sender's upper protocol layers to resend
    missed packets.
    
    dmm

I am in the same boat as .0

I have a customer who is enamoured with the cisco AGS+.

Since the Bridge vs. Router debate is typically a no-win path, I was hoping to
differentiate our products by performance.

According to Wendy Michael, the forwarding rate of the DECbridge 6xx is around
22,200 pps.

I have seen cisco numbers anywhere from 500 pps to 100,000 pps, depending on 
who you talk to, and who pays their salary.   

The generally accepted number is 20,000 pps for FDDI.   This is their current
product, which is encapsulating.  

Now, if their translating product is considerably less, we may still have a 
chance.    But if it comes in even close to 20,000 pps, the FDDI Bridge folks
can kiss this business goodbye for anyone doing TCP/IP.  cisco will win the 
bridge vs router war every time.

Is there anyone in this company (Anil?) who has some *REAL* cisco performance 
numbers?

Bob

Bob,

There are two "independent" performance reports done by LANQuest Labs
by request of Cisco.  The performance reports are titled "A Performance
Analysis of the cisco Systems AGS+", and "Throughput Analysis - Cisco
Systems AGS+ Routers with FDDI Internet" respectively.

I'm just now starting to read these reports myself, so stand by for more
information.  If you are interested in more detail, give me a call.

Merlin

Are there any official performance figures available for customers yet.  One
hears of various figures around 22k pps forwarding from NI (all of them) to 
FDDI.  The products have been around a while now and I can not seem to find
anything official.

Useful statistics would be:

NI Filtering 
FDDI Filtering
Total Filtering
NI-NI forwarding
FDDI-NI (or vice versa) Forwarding

If 100% steady state filtering is not possible with minimum sized packets, 
what size packet will achieve this, again steady state. (I assume the larger
the packet the better on NI-FDDI or does translation slow things up???)

Finally even if we can not filter everything, can we guarantee not to miss
any management or spanning tree massages?

We have always made a proud point of our performance figures in the past, and 
now we seem to have gone strangely silent on the subject. - Not me talking by
the way, but the customer.

Thanks

Dave

My apologies, having RTFM (ie looked in the latest Networks Buyer's Guide), I
see that the following figures are supplied.


				Filter		Forward

DECbridge 500 series		460,000		14,800

DECbridge 600 series		480,000		22,200

I would still be interested in the other bit however.

Dave

My customer is asking about the  forwarding rate perfomance of the DECbridge 620.
Since its forwarding rate is ~22,200pps he has posed the following questions:

- Does the 620 have a full forwarding rate for packets of atleast 150 bytes ?
  If so then is this back to back with no drops ?

- How many back-to-back 64-byte packets can be received on all 3 ethernets and
  forwarded to FDDI before a frame must be dropped due to the finite forwarding
  rate and finite buffer size ?

Answers, pointers or documents would really be appreciated.

Thanks,

Rob

From:	DELNI::PIEPER       "Karl Pieper - FDDI Program Manager DTN 226-5160"  1-JUL-1992 12:17:53.92
To:	LEVERS::S_JACOBS
CC:	PIEPER
Subj:	RE: Bridge Whitepaper

The attached note has been in the DNT Notes file since February pointing to
the DECbridge performance paper.  Feel free to post it in the FDDI notes
file and any other notes files that you feel it needs to be in.  Regards!

Karl


                 <<< ENUF::DISK4$:[NOTES$LIBRARY]DNT.NOTE;1 >>>
                      -< DIGITAL NETWORK TEAM NOTES FILE >-
================================================================================
Note 3112.0         DECbridge 600 Performance Paper Available         No replies
DELNI::PIEPER                                        10 lines  12-FEB-1992 18:07
--------------------------------------------------------------------------------
    
This note is to notify the field that a paper on DECbridge 600 multiport
bridge performance is now available.  A postscript copy of the paper is now
posted in the public NACCIS account on DELNI.

	DELNI::USER$26:[NACCIS.PUBLIC]DECbridge_Performance_Paper.ps

This paper should be read for your own education but can also be distributed
to customers if you desire.  Happy reading!