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RE: Info on MAE-EAST
by Chris A. Icide 14 Jan '97

14 Jan '97

I thought the sizes were comparable as follows... 7010 ~7505 (5 slots, including 1 RP/RSP and 1 SP for the 7010?) 7000 ~7507 (7 slots including 1RP/RSP and 1 SP for the 7000) 7513 (13 slots, no 7000 series comparable) Chris ---------- From: Avi Freedman[SMTP:freedman@netaxs.com] Sent: Tuesday, January 14, 1997 11:18 AM To: Todd R. Stroup Cc: nanog(a)merit.edu Subject: Re: Info on MAE-EAST > Does anyone have any info on if MAE-EAST allows collocation of a 7507 now or > is it still stated that the size has to be about the size of a 7010. > > Please return email direct to tstroup(a)fibernet.net > > Thanks. > > Todd R. Stroup > Fiber Network Solutions, Inc. The 7507 is the same size as the 7010, give or take a few cm, I believe. And unlike Pennsauken, many at MAE-East have full racks available to them. In fact, Netscape has a bunch of purple beasties there (SGIs) last I looked... Avi

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RE: Questions about Internet Packet Losses
by Peter Cole 14 Jan '97

14 Jan '97

People want/need information, Lots of it and lots of different kinds of it. They don't/won't wait on it. Packet loose limits the growth of the Internet by reducing the desire to use the Internet to move different kinds of information. The better it works the more we will all use it, until we get tired of waiting for it. Then we back off and: place a phone call, send a fax, turn on the radio, go to the library or the post office, turn on the TV, read a magazine or newspaper, Install a lease line, etc. ISPs that provides better quality of service will attract content providers and content consumers that want more from the net. As consumers become aware of the differences in service, low performance ISPs will decline in popularity for demanding consumers. Try and find a customer that says they like to wait 30 seconds for a web page. Several of the dialup nationwide systems are 30 second slow. As customers of slow ISPs see faster response from higher quality of service ISPs they will switch or continue to wait. As new solutions are made available to consumers like personal video conferencing, consumers will tend to higher performance ISPs. Even if a carrier delivers ever packet they receive to the Gigaswitch at an exchange point the customer doesn't care where the packet was lost. The increase in private crossconnects sends a message to the exchange points, while giving the exchange point some breathing room. In summation packet loose is here to stay. The amount will be determined by the free market system. P.S. If someone can prove they have better access than what I am buying now I'll plan on switching. AS7201

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Questions about Internet Packet Losses
by Bob Metcalfe 14 Jan '97

14 Jan '97

Hello, and best wishes for what's left of 1997. Now, if you would, ... Below are some questions I hope you'll help me answer about packet loss on the Internet. Here are two paragraphs taken from: http://www.merit.edu/~ipma/netnow/docs/info.html: "Early experiments with NetNow show that 30% packet loss between public exchange points is common for major Internet service providers during peak usage periods. The initial investigation also suggests that loss rates are closely related to bandwidth usage and congestion problems. Although some of the packet loss is inadvertent, a large percentage of the public exchange point connectivity problems reflect intentional engineering decisions by Internet service providers based on commercial settlement issues. "The high packet loss may not generally reflect problems seen by the majority of customers of the larger network service providers. In fact, increasing levels of Internet traffic are not traversing the public exchange points. Instead, many large service providers are migrating their inter-provider traffic to private exchange points, or direct connections to other providers. Merit is working closely with providers to develop tools and infrastructure that more closely reflect Internet performance as observed by the majority of backbone customers." Questions: Are you familiar with this packet loss data from Merit? If not, please see above URL. Is Merit's packet loss data (NetNow) credible? Do packet losses in the Internet now average between 2% and 4% daily? Are 30% packet losses common during peak periods? Is there any evidence that Internet packet losses are trending up or down? If Merit's data is not correct, where has Merit gone wrong? Where is there better data? Were Merit's data correct, what would be the impact of 30% packet losses on opening up TCP connections? On TCP throughput, say through a 28.8Kbps modem? On Web throughput, since so many TCP connections are involved? On DNS look-ups? On email transport? How big a problem is HTTP's opening of so many TCP connections? Does TCP need to operate differently than it does now when confronted routinely with 30% packet losses and quarter-second transit delays? What is the proper response of an IP-based protocol, like TCP, as packet losses climb? Try harder or back off or what? How robust are various widespread TCP/IP implementations in the face of 30% packet loss and quarter-second transit delays? Is the Internet's sometimes bogging down due mainly to packet losses or busy servers or what, or does the Internet not bog down? What fraction of Internet traffic still goes through public exchange points and therefore sees these kinds of packet losses? What fraction of Internet traffic originates and terminates within a single ISP? Where is the data on packet losses experienced by traffic that does not go through public exchange points? If 30% loss impacts are noticeable, what should be done to eliminate the losses or reduce their impacts on Web performance and reliability? Are packet losses due mainly to transient queue buffer overflows of user traffic or to discards by overburdened routing processors or something else? What does Merit mean when they say that some of these losses are intentional because of settlement issues? Are ISPs cooperating intelligently in the carriage of Internet traffic, or are ISPs competing destructively, to the detriment of them and their customers? Any help you can offer on these questions would be appreciated. /Bob Metcalfe, InfoWorld ______________________________________________ ______________________________________________ Dr. Robert M. ("Bob") Metcalfe VP Technology, International Data Group InfoWorld columns: www.infoworld.com Mail: metcalfe(a)infoworld.com Telephone: 617-534-1215 Conference Chairman for ACM97: The Next 50 Years of Computing San Jose Convention Center, March 1-5, 1997 Registration information: www.acm.org/acm97 Register now at 1-800-342-6626 ______________________________________________ ______________________________________________

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FYI: IP NetMonitor for MacOS
by Tom Easterday 14 Jan '97

14 Jan '97

FYI: If you have a Mac there is a tool called IP NetMonitor by Peter Sichel that has whois, tracroute, ping, and a subnet calculator. It is very nice and long overdue (IMHO). I have no ties to it other than I like it. You can try it for free, and it is only $10 to register... http://www.ultranet.com/~psichel/ We now return you to your regularly scheduled program of name calling and finger pointing.. Tom

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NANOG Meeting
by Pam Ciesla 14 Jan '97

14 Jan '97

Other hotels within walking distance to the Grand Hyatt (415- 398-1234). Sir Francis Drake 415-392-7755 $169 Queen, $179 2 Doubles $189 King Cartwright 415-421-2865 Queen or 2 Doubles $109. Kensington Park 415-788-6400 $119 Queen or 2 Doubles. I do not have an answer yet for the room rate at the Grand Hyatt for 2/11, I will let you know ASAP. Pam Ciesla

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RE: Questions about Internet Packet Losses
by Peter Cole 14 Jan '97

14 Jan '97

People want/need information, Lots of it and lots of different kinds of it. They don't/won't wait on it. Packet loose limits the growth of the Internet by reducing the desire to use the Internet to move different kinds of information. The better it works the more we will all use it, until we get tired of waiting for it. Then we back off and: place a phone call, send a fax, turn on the radio, go to the library or the post office, turn on the TV, read a magazine or newspaper, Install a lease line, etc. ISPs that provides better quality of service will attract content providers and content consumers that want more from the net. As consumers become aware of the differences in service, low performance ISPs will decline in popularity for demanding consumers. Try and find a customer that says they like to wait 30 seconds for a web page. Several of the dialup nationwide systems are 30 second slow. As customers of slow ISPs see faster response from higher quality of service ISPs they will switch or continue to wait. As new solutions are made available to consumers like personal video conferencing, consumers will tend to higher performance ISPs. Even if a carrier delivers ever packet they receive to the Gigaswitch at an exchange point the customer doesn't care where the packet was lost. The increase in private crossconnects sends a message to the exchange points, while giving the exchange point some breathing room. In summation packet loose is here to stay. The amount will be determined by the free market system. P.S. If someone can prove they have better access than what I am buying now I'll plan on switching. AS1702

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Grand Hyatt for NANOG Meeting
by Pam Ciesla 14 Jan '97

14 Jan '97

Now has the room rate for 2/11 at $159.00. If you have already made reservations at the higher rate call and have them change it. Pam

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Re: Questions about Internet Packet Losses
by William Allen Simpson 14 Jan '97

14 Jan '97

Yes, Bakul, keeping a central RTT cache per destination is a good idea. Most good stacks use it already. I think it was recommended in Host Requirements circa 1989. Keeping a per destination cache of Path RTT, Path MTU, and a Quality measurement was required in my initial IPng Neighbor Discovery design several years ago, before that was destroyed in the rewrite by committee. > From: Bakul Shah <bakul(a)torrentnet.com> > [Thinking aloud here...] > Perhaps a part of the TCP congestion avoidance algorithm can be > factored out in some sort of a `traffic central' module that tries > to give you the best bandwidth/packet loss estimate it has for a > given route provided you keep it updated with what you learn (i.e. > TCP tells it when a packet is lost etc). A new TCP connection can > then immediately start off with a bigger window (and won't open the > window too wide too quickly). Multiple connections between two > hosts can avoid what would be largely redundant estimate > computation. Even a UDP app. can try to benefit from this (such as > for communication where bounded delay is more critical than packet > loss). Other `traffic conditions' input can also be fed into this > module [perhaps as part of some future routing protocol]. Combining > this `quality' of a route aspect into routing protocols may make > sense in the long run.... > WSimpson(a)UMich.edu Key fingerprint = 17 40 5E 67 15 6F 31 26 DD 0D B9 9B 6A 15 2C 32 BSimpson(a)MorningStar.com Key fingerprint = 2E 07 23 03 C5 62 70 D3 59 B1 4F 5E 1D C2 C1 A2

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Re: Questions about Internet Packet Losses
by Vern Paxson 14 Jan '97

14 Jan '97

> So you'll note that there are very clear spikes at 552 and 576 total packet > size. Further, note that the curve falls off _extremely_ rapidly. From > that, I argue that case (2) _cannot_ be the case because any type of random > distribution would be much smoother. (2) is a random distribution plus some spikes, plus some modality due to TCP's that can only generate packets of <= N bytes for different popular MSS's. So I think it still works (but will save more detailed analysis till later ....). > 2) What OS is using a 512 MSS? >From a bunch of (~ 20,000) traces in my study, looks like Irix 4.0/5.3, BSDI 1.1/2.0, OSF/1 3.0/3.2, and often but not always SunOS use either 512 or 536, or sometimes 500, 524, or 548 (BSDI). Never anything higher. This doesn't mean they *can't* use anything higher, just that they never found an opportunity to do so. 512 is far and away the most common MSS in the traces. (All the TCP's in the traces are BSD variants except for Solaris and Linux.) > 256? My best guess is SLIP links. > 4) 41 bytes is pretty obviously interactive traffic. Is the intuition > correct? That's my guess too. > What's so special about 44, 52, 48 and 56? Ack/SYN/FIN's with options. > What do people do > with 4, 8, 12 and 16 bytes of data? And why not any of the odd values? Because option sizes are rounded up to multiples of 4 bytes. Vern

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Re: Questions about Internet Packet Losses
by Vern Paxson 14 Jan '97

14 Jan '97

> indicate that 9% of the packets had a 512 byte *payload*. > > I already subtracted off the 40 bytes for the headers. I meant MSS. (By payload, I meant data, i.e., not including headers, same as you ...) > However, > the spikes in the packet percentages are clearly due to hosts using that > MSS. You would otherwise expect to see a "smooth" distribution across > packet sizes, which is not at ALL what's happening. Right, spikes correspond to MSS's (and other effects like acks & SYN/FIN's). Are you saying the data shows significant spikes at other, non-standard MSS values? If it does, then (modulo some thinking about the particular numbers) I agree that they're likely MSS candidates and support the notion that weird MSS's are being used. But if the data has a few spikes at things like 512 but no strong spikes at non-standard values, then that doesn't help distinguish between (1) lots of weird TCP's using weird MSS's, vs (2) lots of packets that are less than full-size because the mainstream TCP didn't have enough bytes to fill them. If your data is available, I'd love to take a gander at it. Vern

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