title: Architectural evolution through softwarisation: on the advent of software-defined networks
Creators: name: Ocho, Reuel
Publisher: name: London School of Economics and Political Science (LSE)
Year: 2016
Subjects: subject: H Social Sciences
subject: HD Industries. Land use. Labor
subject: HD28 Management. Industrial Management

description: Digital infrastructures characteristically expand and evolve. Their propensity for growth can be attributed to the self-reinforcing mechanism of positive network externalities, in which the value and attractiveness of any digital infrastructure to users, is generated from and sustained as a function of the size of its existing user community. The expansion of any digital infrastructure, though, is ultimately underpinned by an inherent architectural capacity to support unanticipated change, that may include changes to architecture itself. However, as digital infrastructures scale, their usage grows, and they encounter and become entangled with other digital infrastructures. As such, the capacity of digital infrastructure architecture to accommodate change, under conditions of positive network externalities that attract users, conversely leads to intensified social and technical dependencies that eventually resist certain kinds of change. That is, it leads to sociotechnical ossifications. Changing underlying architecture in existing digital infrastructures, thus, becomes increasingly prohibitive over time.
 Information Systems (IS) research suggests that architectural change or evolution in digital infrastructures occurs primarily via a process of replacement through two means. An existing digital infrastructure is either completely replaced with one that has an evolved architecture, or intermediary transitory gateways are used to facilitate interoperability between digital infrastructures of incompatible architectures. Recognising the sociotechnical ossifications that resist architectural evolution, this literature has also tended to focus more on social activities of cultivating change of which the outcome is architectural evolution in digital infrastructures, than directly on architectural evolution itself. In doing so it has provided only a partial account of underlying architectural evolution in digital infrastructures.
 The findings of this research come from an embedded case study in which changes to underlying architecture in existing networking infrastructures were made. Networking infrastructures are a prime instance of sociotechnically ossified digital infrastructures. The case’s primary data sources included interviews with 39 senior networking and infrastructure virtualisation experts from large Internet and Cloud Service Providers, Standards Development Organisations, Network Equipment Vendors, Network Systems Integrators, Virtualisation Software Technology Organisations, Research Institutes, and as well technical documents. A critical realist analysis was used to uncover generative mechanisms that promote underlying architectural evolution in sociotechnically ossified digital infrastructures.
 This thesis extends IS understanding of architectural evolution in digital infrastructures with the complementary finding of, architectural evolution through softwarisation. In architectural evolution through softwarisation, the architecture of sociotechnically ossified digital infrastructures, is evolved via the exploitation of features inherent to digital entities, which have been overlooked in extant research on architecture in digital infrastructures.