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Given that the new route although longer has better performance I looked at the inter-packet delay variability (IPDV ~ jitter) which should be better if there is more capacity and less congestion. This is borne out, it looks like the IPDV from SLAC to namunu.learn.ac.lk has reduced from about 4-5ms to less than 0.6ms. This is also seen in the Smokeping plot below. In the plot the blue line is the RTT in ms., the grey smudge around the blue line is the jitter, the background colors indicate the losses and black means the host was unreachable at the time the measurement was made (every 30 minutes). !namanu.png!The improved jitter (lack of greay shading) is evident starting on April 1st 2009. The loss of ping connectivity starting on March 24th, 2009 is not understood. The most recent plot is also available.
All LEARN hosts (IP range 192.248.0.0/17 and 2001:df0:17::/48) should be accessible through the TEIN3 link. If we find otherwise, we will let LEARN know and they will sort it out. Looking at a Smokeping graph for SLAC to www.ruh.ac.lk one can see a step change upward in the RTT and what looks to be lower jitter starting on April 1st. See below, the black line showing host unreachable from SLAC for a short time on April 1st 2010 may be caused by the cut-over. The most recent plot is also available. 
Impact on routes from LEARN
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