Using the ping command, monitoring nodes initiate transmissions to remote nodes, then measure and record the response times, or the lack of responses. Each combination of monitoring node-remote node is called a pair. PingER is easy to implement, because little special software must be installed to make measurements. Almost any networked computer will respond to a ping, and require nothing added. Monitoring nodes require only a script to issue ping commands and record results. In September 1999 there were 1977 pairs, consisting of 511 remote nodes in 54 countries. PingER uses the data to determine
latency (round-trip_time),
jitter (variability of round-trip_time), and
loss (percentage of packets that never return). The results of the PingER Project, including source code, are made available to the public at no cost. This collection of data shows long term world-wide Internet performance trends, covering over 750 sites in over 165 countries. Researchers at the
National University of Sciences and Technology, Pakistan, have been dealing with increasingly large amounts of PingER data by using a relational database. From a vantage point between Europe and Africa, researchers at the
International Centre for Theoretical Physics (ICTP) in Italy used PingER to reveal the slow progress of improving Africa's connections to the rest of the world. ==Poor results for Africa==