Performance on the vBNS
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Performance on the vBNS
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(click image to zoom in) |
Performance between SLAC and sites connected to the
vBNS network
is important because many of the physicists
collaborating on SLAC experiments are at universities connected to
this network.
The vBNS network is typically uncongested ( present load can be seen on the vBNS weather map ) and hence we would not expect significant loss or delay in the delivery of packets. The graph to the left shows the monthly packet loss between SLAC and 14 nodes at 11 sites. Not suprisingly the packet loss is low, typically less than 1%, and on only one occassion, in February 1999 did the packet loss exceed 2%, but given the other node at this site didn't experience similar loss it is reasonable to assume this was a problem with the LAN or the machine itself, not a problem with the WAN. |
 (click image to zoom in) |
The graph to the left shows the daily packet loss in November and the first two weeks of December. The packet loss is low with the occassional glitch. These occassional glitches do not seem to coincide, hence the loss is not due to congestion in the vBNS backbone. hence the backbone network is not loaded, at least not for long. |
 (click image to zoom in) |
Only on 3 occassions was there packet loss at the same time to several sites (by eye). Packet loss was observed between other ESnet sites and vBNS that evening. |
 (click image to zoom in) |
We have previously noted observations regarding performance between SLAC and the University of Colorado at Boulder (colorado.edu) when discussing routing. |
Monthly average RTT for Sites in VBNS seen from SLAC
Revised December 15 1999
URL:
http://www-iepm.slac.stanford.edu/
Comments to
iepm-l@slac.stanford.edu