Probelms with performance between SLAC and IHEP.SULes Cottrell and Warren Matthews. Page created: September 19, 2001, last update September 19, 2001.Central Computer Access | Computer Networking | Network Group | ICFA-NTF Monitoring |
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--- usparc.ihep.su ping statistics --- 103 packets transmitted, 12 packets received, 88% packet loss round-trip min/avg/max/mdev = 213.072/219.313/234.612/5.784 ms ksa@osiris $Packet losses of this magnitude (in fact losses over 10-12% make it difficult to maintain a connection) will quickly lead to the TCP connection being broken.
---- usparc.ihep.su (194.190.161.54) PING Statistics ---- 105 packets transmitted, 10 packets received, 90% packet loss round-trip (ms) min/avg/max = 212/216/223 (std = 3.48) 4cottrell@pharlap:~>nping www.ihep.suPings to www.ihep.su measured around the same time on the other hand show much lower packet losses of less than 10%:
---- altair.ihep.su (194.190.161.18) PING Statistics ---- 107 packets transmitted, 102 packets received, 4.7% packet loss round-trip (ms) min/avg/max = 211/215/241 (std = 5.37)Thus it appears that the major part of the problem is in the IHEP LAN, or the machine usparc itself. Comparing the pingroute from SLAC to www.ihep.su witrh the pingroute above from SLAC to usparc.ihep.su confirms the above conclusions.