Defining the GIG Core

The Global Information Grid (GIG) is a large and complex undertaking that is intended to integrate virtually all of the information systems, services, and applications in the US Department of Defense (DoD) into one seamless, reliable, and secure network. In order to achieve the GIG vision of ubiquitous and reliable communications, the GIG will need to support mobility, security and survivability over a core infrastructure built from components of different services and organizations within the US. This paper defines a number of concepts associated with the GIG and discusses two architectural options for constructing the core of the GIG: the striped core and the black core. In all cases, we assume traffic flows are protected in the core using IPsec or similar protocols. While a striped network simplifies the interconnection of core component by making traffic visible at the interconnection point, decrypting and re-encrypting to allow interconnection of core components complicates the end-to-end problem of IPsec gateway discovery, of network routing and of quality of service. As well, decrypting at intermediate nodes compromises the protection of traffic afforded by end-to-end IPsec encryption. We show by example that a black core provides greater flexibility in exploiting network connectivity than a striped core.