vat(1)
showed that the bulk of the
packet loss recurred periodically, with a period around 70-75 seconds.
The cyclic loss varies in intensity, but persists from day to day, week to week.
Where was this loss coming from, and why was it so neatly periodic?
The main tool for examining the state of the multicast Internet is
mtrace(1)
.
It was used here in the form
mtrace -l NASA-MBone-source some-remote-receiver multicast-addressand left to run for a while.
mtrace -l
traces out the path from
the source to the receiver (assumed to be a member of the given
multicast group, i.e. to be currently listening in on that MBone broadcast)
and gathers path and packet-loss statistics at 10-second intervals.
These statistics are plotted below.
For each graph, there's a table of MBone routers in order from source to receiver (hop 0 being the source, etc.). On the graph itself, the various MBone routers are ordered by the range of measured variation in the packet-loss rate, with the widest-swinging MBone router being first.
Please send questions or comments to Stuart Levy, slevy@geom.umn.edu, Geometry Center, University of Minnesota.
nasa-delmarva -- Mtrace from 128.102.84.134 to 138.39.5.48 via group 224.2.210.20
(raw data, GNUplot commands, GNUplot data.)
Nodes, with loss variation (percent over mtrace -l's 10-second intervals):
Hop 0 loss 0.. 0% 224.0.1.32 Hop 1 loss -5.. 5% arcbone.arc.nasa.gov Hop 2 loss -1.. 2% ARC-MBONE.NSN.NASA.GOV Hop 3 loss 0..20% FIXW-MBONE.NSN.NASA.GOV Hop 4 loss 0.. 4% dec3800-2-fddi-1.SanFrancisco.mci.net Hop 5 loss 0.. 3% dec3800-1-fddi-1.Dallas.mci.net Hop 6 loss 0.. 2% dec3800-2-fddi-1.Atlanta.mci.net Hop 7 loss 0.. 2% dec3800-1-fddi-1.NorthRoyalton.mci.net Hop 8 loss -1.. 2% dec3800-1-fddi-1.WestOrange.mci.net Hop 9 loss 0.. 0% multicast.delmarva.com Hop 10 loss 0.. 0% 128.101.25.56
nasa-dk -- Mtrace from 128.102.84.134 to 130.225.16.85 via group 224.2.210.20
(raw data, GNUplot commands, GNUplot data.)
Nodes, with loss variation (percent over mtrace -l's 10-second intervals):
Hop 0 loss 0.. 0% 224.0.1.32 Hop 1 loss 0.. 1% arcbone.arc.nasa.gov Hop 2 loss 0.. 0% ARC-MBONE.NSN.NASA.GOV Hop 3 loss -4..30% FIXW-MBONE.NSN.NASA.GOV Hop 4 loss 0.. 2% dec3800-2-fddi-1.SanFrancisco.mci.net Hop 5 loss 0.. 1% dec3800-1-fddi-1.Dallas.mci.net Hop 6 loss 0.. 3% dec3800-2-fddi-1.Atlanta.mci.net Hop 7 loss 0.. 1% dec3800-1-fddi-1.NorthRoyalton.mci.net Hop 8 loss 0.. 1% dec3800-1-fddi-0.WestOrange.mci.net Hop 9 loss -3.. 4% schnell.ebone.net Hop 10 loss -2.. 3% stockholm.mbone.ebone.net Hop 11 loss 0.. 0% patella.uni-c.dk Hop 12 loss 0.. 0% rhodium.daimi.aau.dk Hop 13 loss 0.. 0% 128.101.25.56
nasa-geom -- Mtrace from 128.102.84.134 to 128.101.25.56 via group 224.2.210.20
(raw data, GNUplot commands, GNUplot data.)
Nodes, with loss variation (percent over mtrace -l's 10-second intervals):
Hop 0 loss 0.. 0% 224.0.1.32 Hop 1 loss -5.. 7% arcbone.arc.nasa.gov Hop 2 loss 0.. 0% ARC-MBONE.NSN.NASA.GOV Hop 3 loss 0..24% FIXW-MBONE.NSN.NASA.GOV Hop 4 loss -1.. 6% dec3800-2-fddi-1.SanFrancisco.mci.net Hop 5 loss -1.. 6% dec3800-2-fddi-1.Denver.mci.net Hop 6 loss 0.. 7% dec3800-1-fddi-1.WillowSprings.mci.net Hop 7 loss -1.. 4% bridge.mr.net Hop 8 loss 0.. 0% hausdorff.geom.umn.edu Hop 9 loss 0.. 0% 128.101.25.56
nasa-isi -- Mtrace from 128.102.84.134 to 128.9.80.62 via group 224.2.210.20
(raw data, GNUplot commands, GNUplot data.)
Nodes, with loss variation (percent over mtrace -l's 10-second intervals):
Hop 0 loss 0.. 0% 224.0.1.32 Hop 1 loss -4.. 6% arcbone.arc.nasa.gov Hop 2 loss 0.. 0% ARC-MBONE.NSN.NASA.GOV Hop 3 loss -1..25% FIXW-MBONE.NSN.NASA.GOV Hop 4 loss 0.. 2% dec3800-2-fddi-0.SanFrancisco.mci.net Hop 5 loss 0.. 1% dec3800-1-fddi-0.LosAngeles.mci.net Hop 6 loss 0.. 5% mbone.ln.net Hop 7 loss 0.. 0% mb80.isi.edu Hop 8 loss 0.. 0% 128.101.25.56
nasa-lbl -- Mtrace from 128.102.84.134 to 131.243.48.193 via group 224.2.210.20
(raw data, GNUplot commands, GNUplot data.)
Nodes, with loss variation (percent over mtrace -l's 10-second intervals):
Hop 0 loss 0.. 0% 224.0.1.32 Hop 1 loss -9..10% arcbone.arc.nasa.gov Hop 2 loss 0.. 1% ARC-MBONE.NSN.NASA.GOV Hop 3 loss -3.. 4% FIXW-MBONE.NSN.NASA.GOV Hop 4 loss -3.. 1% mbone.nsi.nasa.gov Hop 5 loss 0.. 0% llnl-mr2.es.net Hop 6 loss 0.. 0% lbl-mr1-f.es.net Hop 7 loss 0.. 0% er1gw.lbl.gov Hop 8 loss 0.. 0% ir40gw.lbl.gov Hop 9 loss 0.. 0% 128.101.25.56
nasa-sdsc -- Mtrace from 128.102.84.134 to 138.18.5.224 via group 224.2.210.20
(raw data, GNUplot commands, GNUplot data.)
Nodes, with loss variation (percent over mtrace -l's 10-second intervals):
Hop 0 loss 0.. 0% 224.0.1.32 Hop 1 loss -15..14% arcbone.arc.nasa.gov Hop 2 loss 0.. 0% ARC-MBONE.NSN.NASA.GOV Hop 3 loss 0.. 1% FIXW-MBONE.NSN.NASA.GOV Hop 4 loss 0.. 0% nccosc-mbone.dren.net Hop 5 loss 0.. 0% 128.101.25.56
nasa-worldcom -- Mtrace from 128.102.84.134 to 207.247.31.7 via group 224.2.210.20
(raw data, GNUplot commands, GNUplot data.)
Nodes, with loss variation (percent over mtrace -l's 10-second intervals):
Hop 0 loss 0.. 0% 224.0.1.32 Hop 1 loss 0.. 0% arcbone.arc.nasa.gov Hop 2 loss 0.. 0% ARC-MBONE.NSN.NASA.GOV Hop 3 loss 0..25% FIXW-MBONE.NSN.NASA.GOV Hop 4 loss 0.. 3% dec3800-2-fddi-1.SanFrancisco.mci.net Hop 5 loss 0.. 1% dec3800-1-fddi-1.Dallas.mci.net Hop 6 loss 0.. 3% dec3800-2-fddi-1.Atlanta.mci.net Hop 7 loss -1.. 2% atlanta3-mbone1.bbnplanet.net Hop 8 loss 0.. 6% collegepk-mbone1.bbnplanet.net Hop 9 loss 0.. 2% cambridge1-mbone1.bbnplanet.net Hop 10 loss -1.. 3% MBONE3.UU.NET Hop 11 loss 0.. 0% st6.wcomcast.com Hop 12 loss 0.. 0% 128.101.25.56
Nodes, with loss variation (percent over mtrace -l's 10-second intervals):
Hop 0 loss 0.. 0% 224.0.1.32 Hop 1 loss 0.. 1% arcbone.arc.nasa.gov Hop 2 loss 0.. 0% ARC-MBONE.NSN.NASA.GOV Hop 3 loss 0.. 3% maew-mbone.nsn.nasa.gov Hop 4 loss 16..94% sanjose1-mbone1.bbnplanet.net Hop 5 loss -24.. 0% paloalto-mbone1.bbnplanet.net Hop 6 loss -7..10% collegepk-mbone1.bbnplanet.net Hop 7 loss 0.. 2% cambridge1-mbone1.bbnplanet.net Hop 8 loss -2.. 2% MBONE3.UU.NET Hop 9 loss 0.. 0% st6.wcomcast.com Hop 10 loss 0.. 0% 128.101.25.56
Nodes, with loss variation (percent over mtrace -l's 10-second intervals):
Hop 0 loss 0.. 0% cambridge1-mbone1.bbnplanet.net Hop 1 loss 0.. 0% MBONE3.UU.NET Hop 2 loss 0.. 0% st6.wcomcast.com Hop 3 loss 0.. 0% 128.101.25.56
Nodes, with loss variation (percent over mtrace -l's 10-second intervals):
Hop 0 loss 0.. 0% 224.0.1.32 Hop 1 loss -4.. 5% arcbone.arc.nasa.gov Hop 2 loss -2.. 3% ARC-MBONE.NSN.NASA.GOV Hop 3 loss 0.. 0% maew-mbone.nsn.nasa.gov Hop 4 loss 0.. 0% mbone-w.ans.net Hop 5 loss 0.. 0% mbone-e.ans.net Hop 6 loss 0.. 0% collegepk-mbone1.bbnplanet.net Hop 7 loss 0.. 0% cambridge1-mbone1.bbnplanet.net Hop 8 loss 0.. 0% MBONE3.UU.NET Hop 9 loss 0.. 0% st6.wcomcast.com Hop 10 loss 0.. 0% 128.101.25.56
Nodes, with loss variation (percent over mtrace -l's 10-second intervals):
Hop 0 loss 0.. 0% 224.0.1.32 Hop 1 loss 0.. 0% arcbone.arc.nasa.gov Hop 2 loss 0.. 0% ARC-MBONE.NSN.NASA.GOV Hop 3 loss 0.. 0% FIXW-MBONE.NSN.NASA.GOV Hop 4 loss 0.. 1% mbone.nsi.nasa.gov Hop 5 loss 0.. 3% stk-mbone-1.sprintlink.net Hop 6 loss 0.. 7% fw-mbone-1.sprintlink.net Hop 7 loss -99.. 0% dc-mbone-1.sprintlink.net Hop 8 loss 21..28% pen-mbone-1.sprintlink.net Hop 9 loss 0.. 1% mbone1.nap.net Hop 10 loss -1.. 2% MBONE3.UU.NET Hop 11 loss 0.. 0% st6.wcomcast.com Hop 12 loss 0.. 0% 128.101.25.56
Nodes, with loss variation (percent over mtrace -l's 10-second intervals):
Hop 0 loss 0.. 0% 224.0.1.32 Hop 1 loss 0.. 1% arcbone.arc.nasa.gov Hop 2 loss 0.. 0% ARC-MBONE.NSN.NASA.GOV Hop 3 loss 0..21% FIXW-MBONE.NSN.NASA.GOV Hop 4 loss -1.. 3% dec3800-2-fddi-1.SanFrancisco.mci.net Hop 5 loss -1.. 2% dec3800-1-fddi-1.Dallas.mci.net Hop 6 loss 0.. 3% dec3800-2-fddi-1.Atlanta.mci.net Hop 7 loss -2.. 2% atlanta3-mbone1.bbnplanet.net Hop 8 loss -1.. 4% collegepk-mbone1.bbnplanet.net Hop 9 loss -1.. 3% cambridge1-mbone1.bbnplanet.net Hop 10 loss -2.. 5% MBONE3.UU.NET Hop 11 loss 0.. 0% st6.wcomcast.com Hop 12 loss 0.. 0% 128.101.25.56