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A host is considered unreachable if none of the pings sent to it are responded to.  To illustrate this we chose a reliable host at SLAC  (pinger.slac.stanford.edu) and analyzed the unreachability of Pakistani hosts seen from SLAC.

Table of unreachability seen from SLAC to Pakistani hosts in 2010. Higher values (bad) are colored redder. The data is sorted by increasing unreachability in Jan 2011. [Spreadsheet

IEPM:Pakistan^pak-unreach.xlsx]
| Chart of the unreachability of Pakistani hosts seen from SLAC Dec 2010 and Jan 2011
| Smokeping examples of unreachabilltyseen from SLAC for 120 days Oct 2010 - Jan 2011.
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It is seen that several hosts exhibit high unreachability. The reasons behind the high unreliability are usually site specific and vary from lack of reliable power and a source of backup power, floods, lack of access to the site when there are problems that require physical access, lack of expertise, and lack of interest from a site. 

RTT and Losses for 2010



 

The average of the minimum RTT measured between regions of Pakistan between Dec-2009 and November 2010. Spreadsheet

Various percentiles for the Inter Packet Delay Variation (IPDV or jitter) between Pakistani monitoring hosts and remote host pairs. The line shows the number of pairs with measurements contributing to the results. Spreadsheet

The blue dots are the median losses seen between all pairs of monitoring and  remote hosts for each month. The error bars show the extent of the 25 and 75 percentiles. The red dots are the number of pairs contributing to the packet loss measurements. Spreadsheet

 

The minimum RTT to Peshawar and to Islamabad (left hand graph) appears to have reduced dramatically after April 2010. This is partially due to bringing on new hosts that have lower RTT between them.  In April  there was a factor of 2 increase in the number of host pairs (this is seen in the middle and right hand graphs).To try and show the network performance trends within Pakistan in 2010 Amber created a graph showing the inter-regional average RTT performance over the whole year.

Mean Opinion Score (MOS)

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