Kurose & Ross (2010, p772-774) list network monitoring as covering several aspects of the technical failure, performance and capability including: Failure Detection, Host Monitoring, Traffic Monitoring, Rapid Changes in Routing, Service Level Agreement Monitoring and Intrusion Detection. In recent years with the move away from the dedicated point-to-point large scale networks that were used to fulfil critical networking services to the 1990s to using secure channels and virtual private networks that utilise shared and remotely managed network services (e.g. outsourcing to a virtualisation provider), network management has shifted its focus to include many more aspects. As El-Sayed (2009) explored, the historical view of network performance was largely technical along the lines that Kurose & Ross (2010, p772-774) state, however this was largely the view from the network administrator with the objective of keeping the network performing within acceptable technical boundaries, however this does not take into account the requirements of the organisation and other people involved in the network in other areas. For example, a business manager would not be interested in the network itself but possible which nodes are connected and their network utilisation, for commercial reasons.
In my experience with network administrators looking after both local area (LAN) and wide area (WAN) networks with varying degrees of importance placed on the monitoring of the availability and capabilities of each network, it is extremely difficult to find an off-the-shelf network monitoring tool that is capable of providing all of the network information that is required. An interesting aspect of network performance that I encountered a few years ago was to provide an on-going (initially daily) return on investment (ROI) for network performance for a client who charged their client based on bandwidth use of the network. Needless to say the information gathering on traffic between nodes was not a problem however we had to write a specific program to translate this into financial calculations. The moral being that more and more in the real world, simple network monitoring is becoming ever more complex with budgetary and other commercial and operational considerations having to be applied to network performance in today’s critical networking operations.
El-Sayed, A (2009) Ethernet Networks: Current Trends and Tools [Online]. Available at http://www.arxiv.org/pdf/0908.0986 (Accessed 29 May 2011).