Requirements and Architectural Analysis for Precedence Capabilities in the Global Information Grid

This paper provides a perspective and brief analysis of the U.S. Government´s Department of Defense precedence and preemption (P&P) technical requirements for precedence-based assured service (PBAS) capabilities in the global information grid (GIG). Precedence is the user´s indication of the importance of a message. In voice networks, the PBAS capabilities are implemented using multilevel precedence and preemption (MLPP) so that the most important messages get through when either the called end-user is busy or the network is stressed. In the GIG, the PBAS capabilities must be extended to all applications beyond voice and must be implemented in an IP-based quality of service (QoS) architecture. Here we investigate the QoS component of Assured Service (AS). The focus of this paper is on those requirements which would impact the architecture choices for an IP-based packet enterprise transport network, specifically the DoD GIG converged IP transport network. Most existing discussions of precedence and preemption requirements are presented in the context of traditional circuit-based voice services. This paper focuses on the technical requirements and architectural alternatives needed for the implementation of PBAS capabilities in a global enterprise IP-based transport network, irrespective of the applications being transported. This analysis discusses options and tradeoffs for architectures, engineering designs and operational implementations based upon the technical requirements. These options and tradeoffs can be the basis for recommendations for supporting PBAS in the GIG