| T.R | Title | User | Personal Name
 | Date | Lines | 
|---|
| 578.1 |  | KONING::KONING | Paul Koning, A-13683 | Wed May 20 1992 09:49 | 10 | 
|  | The efficiency of FDDI (or for that matter, any other network) is always
less than 100%.  So you definitely cannot get exactly 10 times 10 Mb/s
through the network.
However, efficiencies well above 90% are common.  You should get a copy
of Raj Jain's paper on TTRT; it gives formulas and graphs of efficiency
as a function of TTRT and network size, and explains clearly why it works
that way.
	paul
 | 
| 578.2 | Performance and Guideline paper???? | BRAT::BUKOWSKI |  | Wed May 20 1992 12:58 | 7 | 
|  |     Do you know where there is a good copy of Raj Jain's TTRT paper.  The
    only one I found was FILES::NET$ARCH:[papers]FDDI_PERF.PS;1, and it
    is not legible through CDA viewer.  If you try printing it the print
    defaults to approximately 2 inches on each page (obviously impossible
    to read).
    
    Mike
 | 
| 578.3 |  | KONING::KONING | Paul Koning, A-13683 | Wed May 20 1992 14:32 | 3 | 
|  | Strange.  Ask Raj (ERLANG::JAIN).
	paul
 | 
| 578.4 | 20 Bridges on the FDDI ring | HGSW32::KKHAU | KK Hau @HGO | Thu Dec 23 1993 05:19 | 24 | 
|  | 	Thanks for the above information. I still have question on the Bridge
	If I take the configuration like example 2 on .1, both bridges connect
	FDDI to ethernet 1,2,3,4. Spanning tree starts and turns one bridge go
	to backup mode. But if I put 20 DEChub900 on the FDDI ring, does it
	means that all 20 bridges come to coverge all together. Then, how long
	will these bridges start working when failover starts. The customer 
	was quite concern about the failover time. He does not want the change
	over takes minutes. 
	
	I have to talk more about the case. The customer is going to connect 
	2000 PC running TCP and UDP protocol. He is not allow to fail on the 
	network during business hours since this is a stock exchange site. We
	must make sure that the change over during failure will only be some 
	seconds. In the stock exchange environment, the broker will not wait
	more than 3 seconds of no response from host. The DECbridge 900MX will
	form a FDDI ring by chaining each thru A,B port. The host will be 
	connected to two standalone modules of DECbridge 900MX by AUI ports.
	
	re: .6 Can U give me the mail address of productt manager Jan Brechlin
	so that I can ask him about some figures. We need these figures for 
	preparing the tender to the customer.
	regards
	KK Hau
 | 
| 578.5 |  | KONING::KONING | Paul Koning, B-16504 | Thu Dec 23 1993 12:09 | 9 | 
|  | Each bridge discovers separately whether it should be in backup or in forwarding
mode on each port.  So it takes the SAME amount of time with 20 as it does 
with just 2.  (This is very different from, say, DECnet Phase IV routing,
which takes longer to converge (in certain cases) as the number of routers
increases.)
Jane Brechlin (not "Jan") -- her address is DELNI::BRECHLIN.
	paul
 | 
| 578.6 | wrong posting notes reply | HGSW32::KKHAU | KK Hau @HGO | Tue Dec 28 1993 20:47 | 5 | 
|  | Sorry for wrong posting reply here, it should be hub_managemet notes.
regards
KK
 | 
| 578.7 | how many fddi connects to ring? | MSBCS::HURLEY |  | Wed Oct 09 1996 09:06 | 2 | 
| 578.8 | A maximum of 500 stations... | NETCAD::BATTERSBY |  | Wed Oct 09 1996 09:29 | 1 |