Dynamic inter-SLA resource sharing in path-oriented differentiated services networks

Abstract

Abstract-This paper proposes novel resource sharing schemes for differentiated services (DiffServ) networks, to achieve both high resource utilization and quality of service (QoS) guarantee. Service level agreements (SLAs) are negotiated at network boundaries and supported by path-oriented resource mapping within the network. The recently proposed SLA management scheme based on virtual partitioning (Bouillet et al., 2002) allows overloaded SLAs to exploit the spare capacity of underloaded SLAs for efficient resource utilization, however, at the the cost of possible SLA violation of the underloaders. In the bandwidth borrowing scheme proposed here, the dedicated bandwidth for underloaded SLAs is determined and adaptively adjusted at network boundaries according to the actual traffic load and QoS policies; the available spare capacity is then properly distributed to related links for lending to others. On the other hand, the traffic flows admitted with borrowed bandwidth are tagged and may be preempted later when the original bandwidth owner needs to claim back the resources. Through a detailed implementation design and extensive computer simulation results we show that, by bandwidth borrowing, both SLA compliance and high resource utilization can be achieved in various load conditions, with some side benefits such as call-level service differentiation, small admission overhead, and convenience for policy-based management. In addition, we propose a distributed bandwidth pushing scheme that can dynamically adjust the spare bandwidth distribution over the network. Combining bandwidth pushing with bandwidth borrowing, the resource utilization can be further improved.Index Terms-Bandwidth borrowing, DiffServ, inter-SLA resource sharing, resource allocation, service level agreement.

Efficient Resource Allocation for Policy-Based Wireless/Wireline Interworking

“…Each SLA may apply different policy rules to determine the protection bandwidth and the associated spare capacity. For example, if the SLA is negotiated to guarantee the call blocking probability, the Erlang-B formula can then be used to calculated the protection bandwidth [10]. For a stable SLA management system, sufficient protection bandwidth should be reserved so that the QoS performance of an underloaded SLA is better than or at least as good as the target QoS specification; otherwise, malicious overloading would be encouraged.…”

“…In [9,10], we refer to the inter-SLA resource sharing as bandwidth borrowing; both inter-SLA sharing and bandwidth borrowing are used interchangeably in the following for convenience. When bandwidth borrowing happens, the related unlendable and lendable SLAs are termed as borrower SLAs and lender SLAs, respectively.…”

“…In any scenario, the network status and resource utilization information are mapped to a uniform set of information records as presented in the previous subsection, based on which the bandwidth borrowing scheme [9,10] can then be applied to implement the inter-SLA resource sharing.…”

“…The CAC procedure and associated implementation of all the subroutines presented in [10] are an example of the general procedure given in Fig. 4, where the SLA is to guarantee the call blocking probability (CBP).…”

“…The protection bandwidth is guaranteed for the underloaders to satisfy their QoS requirements during the underloaded periods, and the available spare capacity is then properly distributed to related links to be borrowed by others according to a call-level differentiation policy. The inter-SLA resource sharing concept was first proposed in our work [10] to guarantee the QoS requirement on call blocking probability for all the SLAs involved in the resource sharing. In this paper, we probe further to reveal the potentials of such a resource sharing approach for PBISRA, where the network manager can flexibly design or modify the policy rules that define underload and overload status, determine the bandwidth reservation, or distribute the spare resources among bandwidth borrowers, which are all supported by a common set of resource allocation techniques to enforce the SLA.…”