Path: utzoo!mnetor!uunet!lll-winken!lll-tis!ames!pasteur!ucbvax!BRL.ARPA!phil From: phil@BRL.ARPA (Phil Dykstra) Newsgroups: comp.protocols.tcp-ip Subject: Re: [Phil Dykstra: more interesting numbers] Message-ID: <8804210122.aa04241@SPARK.BRL.ARPA> Date: 21 Apr 88 05:22:25 GMT Sender: daemon@ucbvax.BERKELEY.EDU Organization: The Internet Lines: 42 The numbers that I posted for the NSFNET fuzzies the the ARPA/MILNET Core gateways were for the week ending 21 March 88 (and came via Dave Mills). Only one of the mailbridges and five EGP speakers had been upgraded to 11/73's at that time. It would be interesting to see how they have improved. The numbers for the BRL gateway came from ~48 hours ending 30 March 88. That gateway has three ethernets, one 10 Mbit proteon ring, and two 1822 IMP connections (one MILNET, one local). Packet counts were half of in+out and included everything to/from the interfaces - EGP, ICMP, etc., included. If I had been posting to this list originally I would have spoken a bit more carefully. To answer/comment-on a few replys: > Mike Brescia > ... "average" throughput is a measure of packets actually offered over the > course of the day or week reporting period, .... > ... is a measure of handling offered load rather than limitation. Good point. They were all long term averages. For the record I believe that we all agree that "one packet" goes both in and back out of a gateway. Most vendors seem to count that as two, for obvious reasons. > Phill Gross > Do we understand why the mailbridges have such a higher drop rate? Mike Brescia mentioned a few possible reasons. Another, which I have heard about but don't know any details of, is a claim that the Core gateways maintain max queue lengths of eight packets per destination subnet (I would presume to avoid overloading the PSN's). That probably causes many more drops than a more generous gateway would have (unless there are only PSN's connected to it and they return the favor). > Dave Mills > I would like to believe the difference in drop rates is due to the design > of the NSFNET backfuzz selective-preemption and source-quench schemes. I note however that your numbers went from good to excellent. I am hoping to be able to test that theory by playing the same game locally. - Phil