Oct 26, 2007
stratsec (as SIFT) was engaged by the IT Security Expert Advisory Group (ITSEAG) of the Trusted Information Sharing Network (TISN) to analyse the reliability of the Internet as public and private infrastructure in Australia, including the likelihood and consequences of failure.
The anecdotal evidence suggests that, while the core physical infrastructure of the Internet in Australia and worldwide is robust and reliable, the reliability decreases significantly when assessed at the node level. The reliability of the ‘last mile’ has a significant impact on the reliability of both standard telephone calls and Internet access using this same infrastructure. Fortunately, with sufficient planning the reliability of the ‘last mile’ can be managed by the end-user organisation.
In addition, the core of the Internet is also very reliable at the software level. The capacity and redundancy of the infrastructure in place to manage Internet names and numbers has the ability to withstand significant attacks and outages – and this capacity has been demonstrated through resisting such attacks numerous times over the past five years.
However, the actual delivery of information across the Internet cannot be regarded in the same way. The Internet’s current architecture uses a ‘best efforts’ delivery paradigm rather than a guaranteed end-to-end level of service. This factor was most often cited by critical infrastructure organisations as being the most significant reason why the Internet could not be relied upon for ‘lifeline’ applications.