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From: btk@clem (Bryan Koch)
Newsgroups: comp.protocols.tcp-ip
Subject: References, "best" TCP/IP performance
Message-ID: <8710261757.AA05963@clem.cray.uucp>
Date: Mon, 26-Oct-87 12:57:13 EST
Article-I.D.: clem.8710261757.AA05963
Posted: Mon Oct 26 12:57:13 1987
Date-Received: Thu, 29-Oct-87 23:01:58 EST
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The ARPA Internet
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While TCP/IP performance is constrained by a number of factors (buffer, 
window, and transfer sizes; speed of checksum calculation; hardware
interrupt capacity; I/O bandwidth of supporting hardware), the situation
is not nearly as grim as that assumed by Guru Parulkar's recent request
for information.

We have seen TCP/IP data rates (memory to memory w/data validation by
receiver) of 11 Mbit/second over NSC HYPERchannel media.  
This was seen using 16 Kbyte blocks (MTU) and a 48 Kbyte TCP send/receive
space between two CRAY-2 systems.

Local (software) loopback rates for the same situation exceeds 60 Mbit/sec
using 32KB MTU and 16KB send/receive space on a Cray X-MP/48.

TCP and IP do have problems,  but there is nothing there which constrains
performance to the 1-8 Mbit/sec range.  It would appear from our results
that TCP/IP may well be appropriate protocols for use with FDDI media,
though performance over FDDI will be heavily dependent on the TCP/IP
implementation and parameters.

-Bryan Koch
 Cray Research, Inc.
 btk%hall.cray.com@umn-rei-uc.arpa