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Leaving out the region will assume all regions, leaving out the tier will assume all tiers, leaving out the type will assume both PlanetLabs PingER and SLAC perfSONAR type landmarks. If the region is included then only landmarks in that region will be used. If the tier is specified then only that tier's landmarks will be used. If the type is specified then only that type landmark(s) (e.g. type=PingER,perfSONAR will use only landmark types PingER and perfSONAR) will be used. Any or all of the tier, region and type region may be specified as "all".
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The sites xml files are created a by a trscrontanb running in pinger@pinger.slac.stanford.edu. The script that writes sites.xml is: create_sites-xml.pl. There is also a debug parameter. Use debug=1 or greater if you want debugging output.
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