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It is seen that the links between Karachi and Lahore, Karachi and Islamabad, and Karachi and Peshawar are very direct (values of alpha close to one) and are also very consistent (low values of the standard deviations). Islamabad and Quetta apparently are connected very indirectly (low value of alpha). Looking at the map at the top this makes sense since the route goes via Karachi in the South and then back northwards to Quetta. The links between Islamabad and Lahore, Islamabad and Peshawar and Lahore and Peshawar all have lower vales of alpha and thus appear to be more indirect and have higher variability. A common element in the links between these three regions is that they all pass through Islamabad (see PERN backbone map at top).
Conclusions
- There is a great deal of variability in the reliability (unreachability) of hosts. Much of this is due to loss of power. An effort needs to be made to understand and improve power reliability and the provision of backup for several sites.
- Given the measured MOS, VoIP tools such as Skype should work well between PERN connected hosts.
- The low values of alpha lead to the conclusion that there may be a lot of indirect routing in the Islamabad region. Further work with PERN is required to see if this can be remedied.
- The poor throughput performance to Quetta is understandable. More work need to be done to understand wh Karachi looks so bad.
Acknowledge
We acknowledge the patient and persistent efforts by Kashif Zeeshan and Fahad Gilani of NUST to spearhead the installations of PingER at the various sites. Anjum ? and Adnan Kianai led the efforts at NUST. The PingER map tool was developed by Faisal Zahid while at SLAC and turned out to be extremely effective in drilling down and understanding the connections. The Smokeping tool was developed by Fahad Satti while at SLAC. We also acknowledge the continued encouragement and support from Arshad Ali of NUST.