pathchar(1) pathchar(1) NAME pathchar - Internet path characterization tool SYNOPSIS pathchar [-i is] [-f minttl] [-l maxttl] [-m maxpkt] [-M minpkt] [-p port] [-L fitloc] [-F probefilter] [-q nprobes] [-S fitspacing] [-t tos] [-w wait] ip-address OPTIONS -i min. 51 ms -f min. 1 -l -m min. 128, default 8192 -M min 33, default 64 -p -F min. 0 -q default 32 -L -S min. 0 -t (0-255) -w min. 1 second Per-Link Output Hop Node-Name (Node Address) | bandwidth, prop.time (round trip) [+q queue time (bytes)] [drop %] Typical Output % pathchar ka9q.ampr.org mtu limitted to 1500 bytes at local host doing 32 probes at each of 64 to 1500 by 32 0 localhost | 8.7 Mb/s, 292 us (1.97 ms) 1 ir40gw.lbl.gov (131.243.1.1) | 29 Mb/s, 132 us (2.64 ms) 2 er1gw.lbl.gov (131.243.128.11) | 91 Mb/s, 189 us (3.15 ms) 3 lbl-lc1-1.es.net (198.128.16.11) | 25 Mb/s, 6.92 ms (17.5 ms) 4 gac-atms.es.net (134.55.24.6) | 11 Mb/s, 424 us (19.4 ms) 5 CERFNETGWY.GAT.COM (192.73.7.163) | 7.0 Mb/s, 1.20 ms (23.5 ms) 6 sdsc-ga.cerf.net (134.24.20.15) | ?? b/s, -263 us (22.8 ms) 7 mobydick-fddi.cerf.net (134.24.252.3) | 46 Mb/s, -51 us (22.9 ms) 8 qualcomm-sdsc-ds3.cerf.net (134.24.47.200) | 9.0 Mb/s, 17 us (24.3 ms) 9 krypton-e2.qualcomm.com (192.35.156.2) | 5.5 Mb/s, 1.04 ms (28.6 ms) 10 ascend-max.qualcomm.com (129.46.54.31) | 56.7 Kb/s, 6.19 ms (253 ms) 11 karnp50.qualcomm.com (129.46.90.33) 1 pathchar(1) pathchar(1) | 10 Mb/s, -50 us (253 ms), +q 3.32 ms (6.58 KB) *2 12 unix.ka9q.ampr.org (129.46.90.35) rtt 32 ms (253 ms), bottleneck 56.7 Kb/s, pipe 4706 bytes The lines starting with `|' are the characteristics of the link between the hops listed above & below. The first number is the link bandwidth, the 2nd is the one-way prop time (i.e., for a zero length packet) & the number in parens is the round trip time you would get if there were no queues and you sent a path-mtu sized packet from the source to this hop (i.e., the unloaded data rtt). If there's a queue larger than 1 packet, its size in both time & bytes is printed. If the drop rate is more than 1%, it's printed. Note that it successfully found the LBL FDDI dmz (hops 2-3) & SDSC-Qualcomm T3 (hops 7-8) even though I was run- ning it behind a 10Mb/s ethernet. And that the long hop from San Francisco to San Diego is clearly visible (3-4). (Also note that I was running this at 1am this morning so the normal cerfnet queues were missing & only Phil's P50 ISDN box showed a queue.) DISTRIBUTION From ftp://ftp.ee.lbl.gov/pathchar/ SEE ALSO traceroute, ping AUTHOR Van Jacobson Manual page by Andrew Daviel 2