3. Trips and problems generated in the substations, at any time, are sent
to and displayed on the server which efficiently takes the decisions
and replys to fix those problems.4.5 Network Measurements of the Experimental SCADA System
In order to complete the picture, the following network
measurements were achieved. Two packages were used for this purpose,
Wireshark and CommView.
Wireshark is a free and open-source packet analyzer. It is used for
network troubleshooting, analysis, software and communications protocol
development, and education. Originally named Ethereal, in May 2006 the
project was renamed Wireshark due to trademark issues [ 84 ]. Wireshark
helps interactively browse packet data from a live network or from a
previously saved capture file, and it is software that "understands" the
structure of different networking protocols. Thus, it is able to display the
encapsulation and the fields along with their meanings of different packets
specified by different networking protocols [ 84 ].
Wireshark is used as a measurement tool in the practical part of
this thesis. Packets sizes, delay time, and response time of the received
packets are measured and a filter is applied on captured packets (UDP
protocol and one source substation).
CommView is a powerful network monitor and analyzer
designed for LAN administrators, security professionals, network
programmers, and home users. Loaded with many user-friendly features,
CommView combines performance and flexibility with an ease of use
unmatched in the industry [85]. Captured packets can be examined, saved,
filtered, imported and exported; protocol decodes can be viewed down to
the lowest layer with full analysis of over 70 widespread protocols. With
this information, CommView can help in pinpointing network problems
and troubleshoot software and hardware [85].