CORM: A Concern-Oriented Approach and Model to Computer Network Design

Introduction

Current research in computer networks is at a critical turning point. The research community is endeavoring to devise future network architectures that address the deficiencies identified in present network realizations, acknowledge the need for a trustworthy IT infrastructure, and satisfy the society's emerging and future requirements (Clark, 2010). Considering the lessons from the past, and evaluating the outcomes and contributions of contemporary research literature, the community concluded that the advent of a trustworthy future Internet cannot be achieved by the current trajectory of incremental changes and point solutions to the current computer networks, but rather more revolutionary paths need to be explored (Clark, 2010; Feldmann, 2007). Proposed network architectures need to be grounded on well-articulated design principles that account for network operational and management complexities, embrace technology and application heterogeneity, regulate network inherent emergent behavior, and overcome shortcomings attributed to present network realizations.

Present computer network realizations are the outcome of incremental research efforts and endeavors exerted during the inchoative stage of computer network design. Back then, the aim was to interconnect architecturally disparate networks into one global network. Such inter-network connection was achieved through the introduction of the Transmission Control Protocol (TCP) (Cerf, & Kahn, 1974). TCP was introduced as a flexible protocol that sustains inter-process communication across networks, while hiding any underlying inter-network differences. TCP was later split into TCP and IP leading to the derivation of the layered Internet TCP/IP suite. As such, the TCP/IP suite defined the Internet system, which was regarded as a vehicle to interconnect diverse types of networks. However, the astounding success of the TCP/IP suite in interconnecting networks resulted in adopting the TCP/IP suite as the de facto standard for inter-computer communication within a single network, as well as across multiple networks. An initiative that undermined the need for independent research efforts addressing the requirements and specifications for internally designing computer networks. Focusing primarily on interconnection, TCP/IP networks possessed intelligence at the network edges, while regarding the network core as a “dump forwarding machine,” thus introducing the end-to-end (E2E) design principle; a fundamental principle for TCP/IP networks (Saltzer, Reed, & Clark, 1984). Influenced by TCP/IP-layered architecture and the E2E design principle, network designers and protocol engineers conformed to a top-down design strategy as the approach to architect networks. Moreover, with the introduction of the layered OSI model, the top-down layered approach in network design and protocol engineering was emphasized further, in spite of the fact that the OSI was primarily developed as an “Interconnection Architecture,” i.e. an architecture facilitating the interaction of heterogeneous computer networks rather than an architecture for building computer networks (Zimmermann, 1980).