Introduction to Network Monitoring for the BaBar Collaboration.

SLAC is co-ordinating Internet Performance Monitoring between BaBar sites as part of the Internet End-to-end Performance Monitoring Project (IEPM) funded by DOE/MICS. There are currently 5 monitoring sites, and about 45 remote sites. BaBar users not currently monitored can have their site added by contacting us. For more details on network monitoring at SLAC and related SLAC and other projects, visit Network Monitoring.

SLAC has on 0C3 to ESnet and an additional 0C3 to Stanford campus.

Summary, What every BaBar collaborator should know.

Largely, network connectivity between sites collaborating on the BaBar experiment is good, there is low packet loss and low delay beyond that imposed by the speed of light. Sites connected to SLAC via the Energy Sciences Network (ESnet) and the so-called Internet2 networks, vBNS and Abilene, will experience good connectivity and high performance. Transoceanic links can suffer congestion particularly during the working day of the country trying to connect to SLAC. Many National Research Networks (NRN's) are in the process of upgrading links to the U.S. and ESnet has recently connected to the sites in New York where many of these NRNs connect to. It is expected the performance between SLAC and BaBar collaborators sites will continue the observed long-term trend of improvement.

Confused ? It may help to read the Tutorial on WAN-Monitoring.

Do you have suggestions about what you would like to see explained on this page? Let us know.

Trouble-Shooting

If you have noticed that things aren't what they used to be, and for the last N weeks your FTP transfers have been much slower than they were before, then contact your local network experts, it may be possible you have changed service providers. If your local experts are adamant nothing has changed since before you noticed the change, or if changes are about to occur and you would like us to monitor the effect, please let us know.

If you have just arrived into the office this morning and are having trouble using network applications (e.g. you cannot ssh to SLAC machines or web pages download very slowly) you should first consult your local area network administrator at your university to isolate if problem is local. If problems appear to be at SLAC, use the Reporting Network Problems page, or call 650-926-HELP (650-926-4357). The phone number includes a paging system for off-hours reporting of critical problems.

Revised 16 June 1999
URL: http://www-iepm.slac.stanford.edu/monitoring/babar/intro.html
Comments to iepm-l@slac.stanford.edu