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CERN monitors fewer remote hosts than SLAC (56 versus over 400) so the data is not as complete in the CERN case. Comparing the two graphs, it can be seen that, as expected, the MOS is better for the shorter distances (i.e. CERN to Europe is better than SLAC to Europe, SLAC to N. America is better than CERN to N. America.). It is also seen in both graphs that the Balkans, Russia and Latin America improved dramatically in 2000-2002. Much of Latin America and Russia moved from satellite to land lines in this period. It can be seen from the above plot that VoIP ought to be successful between SLAC and the US, Europe, E. Asia, Russia and the Mid East (all above MOS = 3.5). S. E. Asia is marginal, S. Asia people will have to be very tolerant of one another, and C. Asia and Africa are pretty much out of the question in general. In general the CERN graphs looks similar to the SLAC graph to the various regions, except that S. E. Asia is worse for CERN than SLAC as is S. Asia
The third graph shows the Mean Opinion Score (MOS) from Europe two various regions. We have five monitoring sites in Europe (one at CERN, one at ICTP, one in Germany, and two at UK. The improvement in Latin America and Russia in 2002 is the result of shift from satellite to fiber. The drop for Russia in Sep, 2006 is because we installed a new version of PingER and it started monitoring 9 hosts in Russia whereas previously it was monitoring 20 hosts. For Central Asia the number of sites went up from 3 to 15 in Sep 2006, so the latter results are a better indication of the overall performance of Central Asia. For Sub Sahara Africa the coverage improved in Sep, 2006 (increased from 8 to 39 sites). So for sub Sahara Africa the results after Sep 2006 presents a better picture. South Asia as seen from Europe is performing better than as seen from US because MOS is derived from average RTT which is distance dependent.
The right most graph shows the Mean Opinion Score (MOS) seen from US to South Asian countries. In general South Asian can counties can be divided into two group with India, Pakistan, Sri Lanka and Maldives performing comparatively good (Voice Conference possible but voice quality not that good) whereas Afghanistan, Bangladesh, Nepal and Bhutan are dreadful and Voice conference from US t o these countries is not possible. We have good coverage in India and Pakistan so the results are a good indication of the overall performance. The spike in MOS for Pakistan in July 2005 is the result of fiber outage to Pakistan. The number of sites for Sri Lanka increased from 2 to 6 in Jan 2007 so the results after Jan 2007 is a better indication of the overall performance for Sri Lanka. Before Jan 2007 we were monitoring two hosts in Sri Lanka ( University Of Peradeniya performing very bad . Average RTT > 500 ms and LK Domain Registry performing very good Average RTT < 350 ms). Afghanistan is stuck with satellite connectivity and the land locked countries Nepal and Bhutan have limited fiber connectivity, so they mostly lie at the bottom.
TCP throughput from CERN & SLAC to World Regions
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