Internet Service Provider Network Evolution in the Presence of Changing Environmental Conditions

Internet Service Providers ISPs offer access to the Internet and other network resources to their customers. The ISP marketplace is extremely competitive, requiring ISPs to provide their services with limited resources. In this thesis, we use constrained optimization to reflect the tensions between changing customer demands and infrastructure costs that the ISP faces in its investment decisions. Specifically, we model the traffic routing decisions, the investment in augmenting capacity decisions, and the investment in building network infrastructure decisions made by ISPs. We develop three models a traffic engineering model, a network provisioning model, and a multi-period network provisioning model. To develop our experiments, we use a real ISP, the Abilene network. We focus primarily on explaining the factors that lead to changes in network performance and extract investment policies for ISPs to maximize the effectiveness of limited resources.