Below are the path characterization measurements using pchar between SLAC (nr. San Francisco, California US) and Daresbury Lab (nr. Liverpool England). Both measurements were made on November 2, 2000. They both indicate a roughly 8Mbits/s bottlneck between ESnet and JAnet (see hop 10 for SLAC to DL and hop 9 for DL to SLAC) of about 8-9MBits/s. Between these two networks at this time there was a 10Mbits/sc ATM PVC in New York. It is also intreresting that the bandwidth for the last hop of SLAC to DL (i.e. the hop to rtlin1.dl.ac.uk) does not agree with the bandwidth of the first hop from rtlin1.dl.ac.uk. Pchar works better for hops close to the source so unless there is some asymmetry in this hop then one would choose the the DL to SLAC as being the better estimator. pchar to rtlin1.dl.ac.uk (193.62.119.20) using UDP/IPv4 Packet size increments by 32 to 1500 46 test(s) per repetition 32 repetition(s) per hop 0: 134.79.125.21 (TERSK01.SLAC.Stanford.EDU) Partial loss: 0 / 1472 (0%) Partial char: rtt = 0.333530 ms, (b = 0.000080 ms/B), r2 = 0.945468 stddev rtt = 0.002177, stddev b = 0.000003 Partial queueing: avg = 0.000162 ms (2028 bytes) Hop char: rtt = 0.333530 ms, bw = 100063.638993 Kbps Hop queueing: avg = 0.000162 ms (2028 bytes) 1: 134.79.127.7 (RTR-MSFC-SCS-IR2A.SLAC.Stanford.EDU) Partial loss: 0 / 1472 (0%) Partial char: rtt = 0.519148 ms, (b = 0.000103 ms/B), r2 = 0.925477 stddev rtt = 0.003300, stddev b = 0.000004 Partial queueing: avg = 0.000557 ms (19480 bytes) Hop char: rtt = 0.185617 ms, bw = 353611.040123 Kbps Hop queueing: avg = 0.000395 ms (17452 bytes) 2: 134.79.135.21 (RTR-MSFC-DMZ.SLAC.Stanford.EDU) Partial loss: 0 / 1472 (0%) Partial char: rtt = 0.475823 ms, (b = 0.000153 ms/B), r2 = 0.957653 stddev rtt = 0.003645, stddev b = 0.000005 Partial queueing: avg = 0.003120 ms (70412 bytes) Hop char: rtt = -0.043325 ms, bw = 158958.413112 Kbps Hop queueing: avg = 0.002563 ms (50932 bytes) 3: 192.68.191.66 (ESNET-A-GATEWAY.SLAC.Stanford.EDU) Partial loss: 0 / 1472 (0%) Partial char: rtt = 1.241736 ms, (b = 0.000285 ms/B), r2 = 0.977185 stddev rtt = 0.004931, stddev b = 0.000007 Partial queueing: avg = 0.000361 ms (70412 bytes) Hop char: rtt = 0.765913 ms, bw = 60727.671714 Kbps Hop queueing: avg = -0.002759 ms (0 bytes) 4: 134.55.208.30 (snv-slac.es.net) Partial loss: 0 / 1472 (0%) Partial char: rtt = 76.488855 ms, (b = 0.000336 ms/B), r2 = 0.780644 stddev rtt = 0.020169, stddev b = 0.000027 Partial queueing: avg = 0.000786 ms (78756 bytes) Hop char: rtt = 75.247119 ms, bw = 156921.332174 Kbps Hop queueing: avg = 0.000425 ms (8344 bytes) 5: 134.55.205.22 (nyc-snv.es.net) Partial loss: 0 / 1472 (0%) Partial char: rtt = 76.915041 ms, (b = 0.001108 ms/B), r2 = 0.929464 stddev rtt = 0.034610, stddev b = 0.000046 Partial queueing: avg = 0.002070 ms (80417 bytes) Hop char: rtt = 0.426186 ms, bw = 10354.767737 Kbps Hop queueing: avg = 0.001284 ms (1661 bytes) 6: 193.62.157.5 (193.62.157.5) Partial loss: 0 / 1472 (0%) Partial char: rtt = 143.153322 ms, (b = 0.001268 ms/B), r2 = 0.952082 stddev rtt = 0.032247, stddev b = 0.000043 Partial queueing: avg = 0.001930 ms (80417 bytes) Hop char: rtt = 66.238281 ms, bw = 50096.426546 Kbps Hop queueing: avg = -0.000140 ms (0 bytes) 7: 193.62.157.21 (193.62.157.21) Partial loss: 0 / 1472 (0%) Partial char: rtt = 143.857383 ms, (b = 0.001398 ms/B), r2 = 0.896388 stddev rtt = 0.053893, stddev b = 0.000072 Partial queueing: avg = 0.004777 ms (102258 bytes) Hop char: rtt = 0.704061 ms, bw = 61371.418433 Kbps Hop queueing: avg = 0.002847 ms (21841 bytes) 8: 128.86.1.241 (128.86.1.241) Partial loss: 0 / 1472 (0%) Partial char: rtt = 150.898545 ms, (b = 0.001578 ms/B), r2 = 0.948609 stddev rtt = 0.041634, stddev b = 0.000055 Partial queueing: avg = 0.005376 ms (105592 bytes) Hop char: rtt = 7.041162 ms, bw = 44551.962478 Kbps Hop queueing: avg = 0.000599 ms (3334 bytes) 9: 146.97.253.173 (146.97.253.173) Partial loss: 0 / 1472 (0%) Partial char: rtt = 152.288070 ms, (b = 0.001590 ms/B), r2 = 0.897761 stddev rtt = 0.060826, stddev b = 0.000081 Partial queueing: avg = 0.003584 ms (105592 bytes) Hop char: rtt = 1.389525 ms, bw = 662259.093818 Kbps Hop queueing: avg = -0.001792 ms (0 bytes) 10: 146.97.253.178 (146.97.253.178) Partial loss: 0 / 1472 (0%) Partial char: rtt = 154.213907 ms, (b = 0.002458 ms/B), r2 = 0.931334 stddev rtt = 0.075655, stddev b = 0.000101 Partial queueing: avg = 0.003229 ms (105592 bytes) Hop char: rtt = 1.925838 ms, bw = 9218.858614 Kbps Hop queueing: avg = -0.000355 ms (0 bytes) 11: 194.66.24.2 (gw-dl.netnw.net.uk) Partial loss: 0 / 1472 (0%) Partial char: rtt = 153.397110 ms, (b = 0.002164 ms/B), r2 = 0.943333 stddev rtt = 0.060134, stddev b = 0.000080 Partial queueing: avg = 0.003313 ms (105592 bytes) Hop char: rtt = -0.816797 ms, bw = -27258.364251 Kbps Hop queueing: avg = 0.000084 ms (0 bytes) 12: 193.63.74.233 (gw-fw.dl.ac.uk) Partial loss: 0 / 1472 (0%) Partial char: rtt = 154.361948 ms, (b = 0.002348 ms/B), r2 = 0.930484 stddev rtt = 0.072756, stddev b = 0.000097 Partial queueing: avg = 0.003554 ms (106905 bytes) Hop char: rtt = 0.964838 ms, bw = 43536.136428 Kbps Hop queueing: avg = 0.000241 ms (1313 bytes) 13: 193.63.74.129 (alan3.dl.ac.uk) Partial loss: 0 / 1472 (0%) Partial char: rtt = 160.296081 ms, (b = 0.002399 ms/B), r2 = 0.920715 stddev rtt = 0.079814, stddev b = 0.000106 Partial queueing: avg = 0.003933 ms (114313 bytes) Hop char: rtt = 5.934133 ms, bw = 156271.505477 Kbps Hop queueing: avg = 0.000379 ms (7408 bytes) 14: 193.62.127.101 (s48-nd.dl.ac.uk) Partial loss: 241 / 1472 (16%) Partial char: rtt = 154.779243 ms, (b = 0.003408 ms/B), r2 = 0.948474 stddev rtt = 0.090042, stddev b = 0.000120 Partial queueing: avg = 0.004228 ms (114605 bytes) Hop char: rtt = -5.516838 ms, bw = 7932.686520 Kbps Hop queueing: avg = 0.000295 ms (292 bytes) 15: 193.62.119.20 (rtlin1.dl.ac.uk) Path length: 15 hops Path char: rtt = 154.779243 ms, r2 = 0.948474 Path bottleneck: 7932.686520 Kbps Path pipe: 153476 bytes Path queueing: average = 0.004228 ms (114605 bytes) [cottrell@rtlin1 cottrell]$ /usr/local/bin/pchar pharlap.slac.stanford.edu pchar to pharlap.slac.stanford.edu (134.79.16.102) using UDP/IPv4 Packet size increments by 32 to 1500 46 test(s) per repetition 32 repetition(s) per hop 0: 193.62.119.20 (rtlin1.dl.ac.uk) Partial loss: 0 / 1472 (0%) Partial char: rtt = 0.491533 ms, (b = 0.000238 ms/B), r2 = 0.996953 stddev rtt = 0.001491, stddev b = 0.000002 Partial queueing: avg = 0.000012 ms (51 bytes) Hop char: rtt = 0.491533 ms, bw = 33627.452569 Kbps Hop queueing: avg = 0.000012 ms (51 bytes) 1: 193.62.119.1 (s48-nd.dl.ac.uk) Partial loss: 0 / 1472 (0%) Partial char: rtt = 0.875072 ms, (b = 0.000315 ms/B), r2 = 0.997502 stddev rtt = 0.001788, stddev b = 0.000002 Partial queueing: avg = 0.000550 ms (7019 bytes) Hop char: rtt = 0.383539 ms, bw = 103599.880204 Kbps Hop queueing: avg = 0.000538 ms (6968 bytes) 2: 193.62.127.1 (alan3.dl.ac.uk) Partial loss: 0 / 1472 (0%) Partial char: rtt = 1.166603 ms, (b = 0.000375 ms/B), r2 = 0.996470 stddev rtt = 0.002533, stddev b = 0.000003 Partial queueing: avg = 0.000651 ms (8691 bytes) Hop char: rtt = 0.291530 ms, bw = 132816.279516 Kbps Hop queueing: avg = 0.000101 ms (1672 bytes) 3: 193.63.74.131 (gw-fw.dl.ac.uk) Partial loss: 0 / 1472 (0%) Partial char: rtt = 1.756641 ms, (b = 0.000924 ms/B), r2 = 0.935645 stddev rtt = 0.027462, stddev b = 0.000037 Partial queueing: avg = 0.000547 ms (8691 bytes) Hop char: rtt = 0.590038 ms, bw = 14590.957982 Kbps Hop queueing: avg = -0.000104 ms (0 bytes) 4: 193.63.74.232 (nnw-gw.dl.ac.uk) Partial loss: 0 / 1472 (0%) Partial char: rtt = 2.727997 ms, (b = 0.000791 ms/B), r2 = 0.972593 stddev rtt = 0.015046, stddev b = 0.000020 Partial queueing: avg = 0.001321 ms (8691 bytes) Hop char: rtt = 0.971357 ms, bw = -60141.696006 Kbps Hop queueing: avg = 0.000774 ms (0 bytes) 5: 194.66.24.250 (gw-metro.netnw.net.uk) Partial loss: 0 / 1472 (0%) Partial char: rtt = 3.249029 ms, (b = 0.000879 ms/B), r2 = 0.835814 stddev rtt = 0.044182, stddev b = 0.000059 Partial queueing: avg = 0.002948 ms (27043 bytes) Hop char: rtt = 0.521032 ms, bw = 90214.504597 Kbps Hop queueing: avg = 0.001627 ms (18352 bytes) 6: 146.97.255.177 (nw-gw.ja.net) Partial loss: 0 / 1472 (0%) Partial char: rtt = 10.674055 ms, (b = 0.000823 ms/B), r2 = 0.870801 stddev rtt = 0.035944, stddev b = 0.000048 Partial queueing: avg = 0.002037 ms (27043 bytes) Hop char: rtt = 7.425026 ms, bw = -142412.515438 Kbps Hop queueing: avg = -0.000911 ms (0 bytes) 7: 193.62.157.81 (ext-gw3.ja.net) Partial loss: 0 / 1472 (0%) Partial char: rtt = 11.040212 ms, (b = 0.001127 ms/B), r2 = 0.849949 stddev rtt = 0.053704, stddev b = 0.000071 Partial queueing: avg = 0.005784 ms (39357 bytes) Hop char: rtt = 0.366157 ms, bw = 26288.710719 Kbps Hop queueing: avg = 0.003747 ms (12314 bytes) 8: 193.63.94.95 (us-gw3.ja.net) Partial loss: 0 / 1472 (0%) Partial char: rtt = 78.396525 ms, (b = 0.001199 ms/B), r2 = 0.735804 stddev rtt = 0.081431, stddev b = 0.000108 Partial queueing: avg = 0.002461 ms (39357 bytes) Hop char: rtt = 67.356313 ms, bw = 112238.805970 Kbps Hop queueing: avg = -0.003323 ms (0 bytes) 9: 193.62.157.18 (ny-pop.ja.net) Partial loss: 1 / 1472 (0%) Partial char: rtt = 79.103484 ms, (b = 0.002097 ms/B), r2 = 0.914955 stddev rtt = 0.072475, stddev b = 0.000096 Partial queueing: avg = 0.004640 ms (41783 bytes) Hop char: rtt = 0.706959 ms, bw = 8907.180393 Kbps Hop queueing: avg = 0.002179 ms (2426 bytes) 10: 193.62.157.6 (ny-pop.esnet.ja.net) Partial loss: 0 / 1472 (0%) Partial char: rtt = 153.867988 ms, (b = 0.002252 ms/B), r2 = 0.885221 stddev rtt = 0.091919, stddev b = 0.000122 Partial queueing: avg = 0.004720 ms (42299 bytes) Hop char: rtt = 74.764504 ms, bw = 51670.338698 Kbps Hop queueing: avg = 0.000080 ms (516 bytes) 11: 134.55.205.21 (snv-nyc.es.net) Partial loss: 0 / 1472 (0%) Partial char: rtt = 163.860962 ms, (b = 0.002005 ms/B), r2 = 0.897204 stddev rtt = 0.076931, stddev b = 0.000102 Partial queueing: avg = 0.006821 ms (42299 bytes) Hop char: rtt = 9.992974 ms, bw = -32401.648558 Kbps Hop queueing: avg = 0.002101 ms (0 bytes) 12: 134.55.208.29 (slac-snv.es.net) Partial loss: 0 / 1472 (0%) Partial char: rtt = 155.677055 ms, (b = 0.002407 ms/B), r2 = 0.932382 stddev rtt = 0.073478, stddev b = 0.000098 Partial queueing: avg = 0.004830 ms (42299 bytes) Hop char: rtt = -8.183907 ms, bw = 19902.287470 Kbps Hop queueing: avg = -0.001990 ms (0 bytes) 13: 192.68.191.69 (RTR-MSFC-DMZ.SLAC.Stanford.EDU) Partial loss: 1472 / 1472 (100%) Partial char: rtt = 0.000000 ms, (b = 0.000000 ms/B), r2 = 0.000000 stddev rtt = 0.000000, stddev b = 0.000000 Partial queueing: avg = 0.000000 ms (42299 bytes) Hop char: rtt = 0.000000 ms, bw = 0.000000 Kbps Hop queueing: avg = -0.004830 ms (0 bytes) 14: 41.0.0.0 (41.0.0.0) Path length: 14 hops Path char: rtt = 0.000000 ms, r2 = 0.000000 Path bottleneck: 8907.180393 Kbps Path pipe: 0 bytes Path queueing: average = 0.000000 ms (42299 bytes)