Supporting service differentiation through end-to-end QoS routing

Providing better than best-effort service in the current Internet paradigm requires support from the underlying network infrastructure. The IntServ (integrated services) model was proposed for guaranteeing per-flow, end-to-end quality of service (QoS). However, IntServ model is too restrictive for large-scale deployment for providing QoS in the Internet due to its scalability problem. Faced with this problem, the DiffServ (differentiated services) model has been proposed, and now is becoming the preferred solution. DiffServ aims to resolve the scalability problem existing in the IntServ. Based on the idea of traffic aggregation, DiffServ intends to be a scalable, flexible approach for supporting multiple levels of service. However, the DiffServ model has not provided sufficient mechanisms to efficiently manage network resources and effectively control traffic admission into core networks. In this paper, we apply the seminal concepts of DiffServ and bandwidth brokers (BB) to design the end-to-end SiMO (single service multiple options) routing framework. The goals are three-fold, namely (1) supporting SiMO service differentiation through QoS routing; (2) combining resources management and admission control with QoS routing; and (3) enhancing the end-to-end performance guarantee to per aggregate class. Through extensive simulation using two kinds of applications, i.e., IP telephony and MPEG streams, we have demonstrated that the SiMO routing framework is capable of providing QoS service by supplying paths with different end-to-end delay characteristics to per aggregate classes.