For ISPs belonging to the so-called service factory industry, the most critical competitive edge comes from back room operations such as cost effective network infrastructure configuration and coordination capability of network operations/management. This thesis first presents the scalability problem arising in the course of ISP network (AS, Autonomous System) operations. Regarding link-state routing protocols, in particular, provided is an overall conceptual framework for hierarchical configuration to deal with the scalability issue while minimizing side effects from introducing hierarchy, for example degradation of service reliability. Then, addressed and analyzed are two problems and solution methods for (1) scalable and hierarchical domain partition and (2) backbone connectivity augmentation, each of which constitutes a core module in the proposed overall HC scheme. Lastly, with the ISP AS defined as a service operations system that provides Internet connectivity to its subscribers, the appendix introduces and discusses a new perspective and conceptual analysis decision tools for service level management and peering in ISP industry.