<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<style type="text/css" style="display:none;"> P {margin-top:0;margin-bottom:0;} </style>
</head>
<body dir="ltr">
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Hello Saku,</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Thank you for the summary. We're clear about the fact that what we're seeing are MLPS paths - that was not in question. What we are not clear about and the reason for the post is why the provider - zayo.telia in this case - would decide to configure MPLS
paths between Chicago and distant international locations. We assumed we would see hops in traceroute between Chicago and coastal locations and then hops that transited submarine infrastructure followed by hops to large population centers.</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Regards, PB</div>
<div id="appendonsend"></div>
<hr style="display:inline-block;width:98%" tabindex="-1">
<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> Saku Ytti <saku@ytti.fi><br>
<b>Sent:</b> Tuesday, January 18, 2022 12:50 AM<br>
<b>To:</b> PAUL R BARFORD <pb@cs.wisc.edu><br>
<b>Cc:</b> Lukas Tribus <lukas@ltri.eu>; Esteban Carisimo <esteban.carisimo@northwestern.edu>; nanog@nanog.org <nanog@nanog.org>; Fabian E. Bustamante <fabianb@cs.northwestern.edu><br>
<b>Subject:</b> Re: Long hops on international paths</font>
<div> </div>
</div>
<div class="BodyFragment"><font size="2"><span style="font-size:11pt;">
<div class="PlainText">1) all (meaning all hitting the zayo.telia) your traceroutes originate<br>
from University in Chicago<br>
2) the zayo.telia device is physically close to the university<br>
3) we should expect physically close-by backbone device to be present<br>
in disproportionate amount of traceroutes<br>
4) almost certainly zayo.telia is imposing the MPLS label of TTL 255,<br>
_NOT_ copying IP TTL, therefore until MPLS label is popped, TTL is not<br>
expiring. I.e. you are seeing ingressPE and egress PE ot Telia, you<br>
are not seeing any P routers.<br>
<br>
This is not esoteric knowledge, but a fairly basic Internet concept. I<br>
am worried you are missing too much context to produce actionable<br>
output from your work. It might be interesting to see your curriculum,<br>
why this confusion arose, why it seems logical that the reason must be<br>
that almost all waves are terminated there, because it would not seem<br>
logical for people practising in the field who have even cursory<br>
understanding, this implies problems in the curriculum.<br>
<br>
On Tue, 18 Jan 2022 at 07:21, PAUL R BARFORD <pb@cs.wisc.edu> wrote:<br>
><br>
> Please find the examples for the case of Telia below.<br>
><br>
> FROM jfk-us (jfk-us.team-probing.c008820.20201002.warts.gz)<br>
><br>
><br>
><br>
> traceroute from 216.66.30.102 (Ark probe hosted in New York City, NY, US. No AS info found) to 223.114.235.32 (MAXMIXD: Turpan, CN)<br>
><br>
> 1 216.66.30.101 0.365 ms<br>
><br>
> 2 62.115.49.173 3.182 ms<br>
><br>
> 3 *<br>
><br>
> 4 62.115.137.59 17.453 ms [x] (chi-b23-link.ip.twelve99.net., CAIDA-GEOLOC -> Chicago, IL, US)<br>
><br>
> 5 62.115.117.48 59.921 ms [x] (sea-b2-link.ip.twelve99.net., RIPE-IPMAP -> Seattle, WA, US)<br>
><br>
> 6 62.115.171.221 69.993 ms<br>
><br>
> 7 223.120.6.53 69.378 ms<br>
><br>
> 8 223.120.12.34 226.225 ms<br>
><br>
> 9 221.183.55.110 237.475 ms<br>
><br>
> 10 221.183.25.201 238.697 ms<br>
><br>
> 11 221.176.16.213 242.296 ms<br>
><br>
> 12 221.183.36.62 352.695 ms<br>
><br>
> 13 221.183.39.2 300.166 ms<br>
><br>
> 14 117.191.8.118 316.270 ms<br>
><br>
> 15 *<br>
><br>
> 16 *<br>
><br>
> 17 *<br>
><br>
> 18 *<br>
><br>
> 19 *<br>
><br>
><br>
><br>
><br>
><br>
> FROM ord-us (ord-us.team-probing.c008820.20201002.warts.gz)<br>
><br>
><br>
><br>
> traceroute from 140.192.218.138 (Ark probe hosted in Chicago, IL, US at Depaul University-AS20120) to 109.25.215.237 (237.215.25.109.rev.sfr.net., MAXMIXD: La Crau, FR)<br>
><br>
> 1 140.192.218.129 0.795 ms<br>
><br>
> 2 140.192.9.124 0.603 ms<br>
><br>
> 3 64.124.44.158 1.099 ms<br>
><br>
> 4 64.125.31.172 3.047 ms<br>
><br>
> 5 *<br>
><br>
> 6 64.125.15.65 1.895 ms [x] (zayo.telia.ter1.ord7.us.zip.zayo.com., CAIDA-GEOLOC -> Chicago, IL, US)<br>
><br>
> 7 62.115.118.59 99.242 ms [x] (prs-b3-link.ip.twelve99.net., CAIDA-GEOLOC -> Paris, FR)<br>
><br>
> 8 62.115.154.23 105.214 ms<br>
><br>
> 9 77.136.10.6 119.021 ms<br>
><br>
> 10 77.136.10.6 118.830 ms<br>
><br>
> 11 80.118.89.202 118.690 ms<br>
><br>
> 12 80.118.89.234 118.986 ms<br>
><br>
> 13 109.24.108.66 119.159 ms<br>
><br>
> 14 109.25.215.237 126.085 ms<br>
><br>
><br>
><br>
><br>
><br>
> traceroute from 140.192.218.138 (Ark probe hosted in Chicago, IL, US at Depaul University-AS20120) to 84.249.89.93 (dsl-tkubng12-54f959-93.dhcp.inet.fi., MAXMIXD: Turku, FI)<br>
><br>
> 1 140.192.218.129 0.243 ms<br>
><br>
> 2 140.192.9.124 0.326 ms<br>
><br>
> 3 64.124.44.158 0.600 ms<br>
><br>
> 4 *<br>
><br>
> 5 *<br>
><br>
> 6 64.125.15.65 1.792 ms [x] (zayo.telia.ter1.ord7.us.zip.zayo.com., CAIDA-GEOLOC -> Chicago, IL, US)<br>
><br>
> 7 62.115.123.27 121.199 ms [x] (hls-b4-link.ip.twelve99.net., CAIDA-GEOLOC -> Helsinki, FI)<br>
><br>
> 8 *<br>
><br>
> 9 141.208.193.190 127.723 ms<br>
><br>
> 10 84.249.89.93 139.051 ms<br>
><br>
><br>
><br>
><br>
><br>
> traceroute from 140.192.218.138 (Ark probe hosted in Chicago, IL, US) to 193.28.231.50 (MAXMIXD: None, HU)<br>
><br>
> 1 140.192.218.129 0.240 ms<br>
><br>
> 2 140.192.9.124 0.333 ms<br>
><br>
> 3 64.124.44.158 0.648 ms<br>
><br>
> 4 *<br>
><br>
> 5 64.125.25.75 0.752 ms<br>
><br>
> 6 64.125.15.65 1.877 ms [x] (zayo.telia.ter1.ord7.us.zip.zayo.com., CAIDA-GEOLOC -> Chicago, IL, US)<br>
><br>
> 7 62.115.119.39 123.952 ms [x] (bpt-b2-link.ip.twelve99.net., **I suspect it is in Budapest, HU**)<br>
><br>
> 8 62.115.39.122 117.171 ms<br>
><br>
> 9 88.151.96.148 117.202 ms<br>
><br>
> 10 88.151.96.213 124.787 ms<br>
><br>
> 11 *<br>
><br>
> 12 *<br>
><br>
> 13 *<br>
><br>
> 14 *<br>
><br>
> 15 *<br>
><br>
><br>
><br>
><br>
><br>
> traceroute from 140.192.218.138 (Ark probe hosted in Chicago, IL, US at Depaul University-AS20120) to 152.195.4.11 (MAXMIXD: Los Angeles, CA, US)<br>
><br>
> 1 140.192.218.129 0.224 ms<br>
><br>
> 2 140.192.9.124 0.545 ms<br>
><br>
> 3 64.124.44.158 0.640 ms<br>
><br>
> 4 *<br>
><br>
> 5 *<br>
><br>
> 6 64.125.15.65 1.786 ms [x] (zayo.telia.ter1.ord7.us.zip.zayo.com., CAIDA-GEOLOC -> Chicago, IL, US)<br>
><br>
> 7 62.115.118.247 54.597 ms [x] (las-b22-link.ip.twelve99.net., CAIDA-GEOLOC -> Los Angeles, CA, US)<br>
><br>
> 8 62.115.11.129 55.979 ms<br>
><br>
> 9 *<br>
><br>
> 10 *<br>
><br>
> 11 *<br>
><br>
> 12 *<br>
><br>
> 13 *<br>
><br>
><br>
><br>
><br>
><br>
> traceroute from 140.192.218.138 (Ark probe hosted in Chicago, IL, US at Depaul University-AS20120) to 47.31.143.217 (MAXMIXD: Delhi, IN)<br>
><br>
> 1 140.192.218.129 2.277 ms<br>
><br>
> 2 140.192.9.124 0.449 ms<br>
><br>
> 3 64.124.44.158 0.576 ms<br>
><br>
> 4 *<br>
><br>
> 5 *<br>
><br>
> 6 64.125.15.65 1.814 ms [x] (zayo.telia.ter1.ord7.us.zip.zayo.com., CAIDA-GEOLOC -> Chicago, IL, US)<br>
><br>
> 7 62.115.114.41 210.056 ms [x] (snge-b5-link.ip.twelve99.net.,)<br>
><br>
> 8 62.115.177.11 200.840 ms<br>
><br>
> 9 103.198.140.16 233.636 ms<br>
><br>
> 10 103.198.140.16 232.871 ms<br>
><br>
> 11 103.198.140.171 232.648 ms<br>
><br>
> 12 *<br>
><br>
> 13 *<br>
><br>
> 14 *<br>
><br>
> 15 *<br>
><br>
> 16 *<br>
><br>
><br>
> ________________________________<br>
> From: Lukas Tribus <lukas@ltri.eu><br>
> Sent: Monday, January 17, 2022 1:52 PM<br>
> To: PAUL R BARFORD <pb@cs.wisc.edu><br>
> Cc: Nick Hilliard <nick@foobar.org>; nanog@nanog.org <nanog@nanog.org>; Esteban Carisimo <esteban.carisimo@northwestern.edu>; Fabian E. Bustamante <fabianb@cs.northwestern.edu><br>
> Subject: Re: Long hops on international paths<br>
><br>
> On Mon, 17 Jan 2022 at 20:00, PAUL R BARFORD <pb@cs.wisc.edu> wrote:<br>
> > What we're curious about is why we're seeing a concentration of hops at a small number of routers that appear on international paths.<br>
><br>
> I suggest you share a few actual examples (IP addresses, traceroutes).<br>
><br>
> I don't think discussing your conclusion based on data we don't have<br>
> makes sense.<br>
><br>
><br>
> Lukas<br>
<br>
<br>
<br>
-- <br>
++ytti<br>
</div>
</span></font></div>
</body>
</html>