Topology Abstraction Service for IP VPNs: Core Network Partitioning for Resource Sharing

TL;DR

This paper introduces centralized network partitioning schemes for IP VPNs to improve resource sharing and fairness, building on decentralized abstraction methods and evaluating their performance through extensive simulations.

Contribution

It develops centralized capacity partitioning schemes for VPNs, addressing fairness issues and enhancing resource abstraction accuracy over prior decentralized approaches.

Findings

Centralized schemes outperform decentralized ones in resource utilization.

Fairness can be improved with specific MMCF-based partitioning methods.

Simulation results demonstrate better call performance and abstraction efficiency.

Abstract

VPN service providers (VSP) and IP-VPN customers have traditionally maintained service demarcation boundaries between their routing and signaling entities. This has resulted in the VPNs viewing the VSP network as an opaque entity and therefore limiting any meaningful interaction between the VSP and the VPNs. A key challenge is to expose each VPN to information about available network resources through an abstraction (TA) [1] which is both accurate and fair. In [2] we proposed three decentralized schemes assuming that all the border nodes performing the abstraction have access to the entire core network topology. This assumption likely leads to over- or under-subscription. In this paper we develop centralized schemes to partition the core network capacities, and assign each partition to a specific VPN for applying the decentralized abstraction schemes presented in [2]. First, we present two schemes based on the maximum concurrent flow and the maximum multicommodity flow (MMCF) formulations. We then propose approaches to address the fairness concerns that arise when MMCF formulation is used. We present results based on extensive simulations on several topologies, and provide a comparative evaluation of the different schemes in terms of abstraction efficiency, fairness to VPNs and call performance characteristics achieved.