| 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 |
(crossposted in the DWT and Internet Notesfiles)
Has anybody seen any benchmarks that show throughput at the TCP level
through the DECstation 5000's FDDI controller?
My customer wants to write an application that accepts a multiple
streams of TCP packets from networked data acquisition devices on an
FDDI ring, merges them into a single stream and puts them back on the
ring for archiving by a networked tape device.
The customer wants to know how many acqusition devices he can support
before he chokes the DECstation. He wants to know what the throughput
from the merge process to and from the FDDI controller is.
Any guesses as to how much load this type of activity would place on
the O/S?
As always, any help is appreciated.
Regards,
John
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 177.1 | Your results WILL vary | ENUF::CAUDILL | Kelly-T&N Mkg Tech Supp - 264-3320 | Wed Dec 12 1990 19:17 | 19 |
I haven't seen any real benchmarks, but I seem to remember seeing a
demo somewhere which used DECstation 5000s to send data over the FDDI.
As I recall, in this demo, the fastest one DS5000 could send TCP
packets to another DS5000 over FDDI was around 18mega-bits-per-second
(that's only counting the user data). This was with max sized packets.
With smaller packets, the throughput would reduce. The main
performance factor is packets-per-second rather than bits-per-second.
With UDP, however, the demo could get up to 33mega-bits-per-second.
The difference between the throughput with UDP versus TCP was due to
the processing overhead in the TCP code (versus the UDP code) in ULTRIX.
Running TCP at 18meg took 100% of the DS5000 CPU while the FDDI
controller and the bus were not even breathing hard.
Of course this was just a demo, not a benchmark. The demo performed no
processing on the data which it sent or received - the sender just sent
a preallocated buffer filled with x00 and receiver through the data away.
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