Specifications
APPENDIX C. RESULTS OBTAINED DURING DEVELOPMENT 39
clocks lose their synchronization [4]) so the preferred method is the one that corrects the
clocks at each second.
The test involves recording the values of all counters in the system at each second, as
triggered by the 1Hz PPS signal from the GPS. The table found in Appendix A.4.4 on page
32 shows some of these values.
A second test was to run ping type program (echo – reply) that measures the one-way
delay and the round trip time b etween the 2 sites. Some results are given below and can
be observed that the one-way delay is half of the round trip time.
64 bytes from pcatbgps01.cern.ch (137.138.203.40):
icmp_seq=7 ttl=250 time=758 usec oneway delay: 360.448000 usec
64 bytes from pcatbgps01.cern.ch (137.138.203.40):
icmp_seq=8 ttl=250 time=756 usec oneway delay: 368.640000 u sec
64 bytes from pcatbgps01.cern.ch (137.138.203.40):
icmp_seq=9 ttl=250 time=761 usec oneway delay: 376.832000 u sec