Virtual network embedding with collocation: Benefits and limitations of pre-clustering

Abstract

Abstract-Given that mechanisms for resource isolation are in place, the collocation of virtual network (VNet) nodes is attractive as it reduces the inter-machine communication and hence improves the VNet embedding. However, existing VNet embedding algorithms either do not support the collocation of virtual nodes of the same VNet, or only support it implicitly by referring to the possibility to pre-cluster the VNet topology: this pre-clustered network forms the new VNet request and is embedded accordingly.This paper presents a pre-clustering algorithm OPTCUT that is optimal in the sense that it minimizes the amount of link resources needed for the embedding. It is based on a smart linear program formulation that ensures fast solutions. OPTCUT can be used together with any existing VNet embedding algorithms, and we show that it can greatly improve the state-of-the-art embedding algorithm SecondNet [16]. The paper also describes a simple algorithm LOCO that directly supports collocation. This algorithm is part of a novel and generic VNet embedding framework METATREE which may be of independent interest.We compare the performance of the pre-clustering approaches with the direct VNet embeddings by LOCO, and find that preclustering also has its limitations. In particular, the information gap between the pre-clustering and the actual algorithm, as well as an inaccurate estimation of the distribution of remaining substrate resources, may lead to a low network utilization.

Impact of processing costs on service chain placement in network functions virtualization

“…In our problem, the SCs can be seen as simple-chain virtual graphs, where the chained VNFs are virtual nodes connected together by virtual links. Such SCs must be embedded in a physical network, where each virtual link can be mapped to a physical path [6], multiple virtual nodes can be mapped to the same physical node [7], and the virtual nodes must be consolidated [8]. With respect to Refs.…”

Adversarial topology discovery in network virtualization environments: a threat for ISPs?

“…The embeddings of VNets is an intensively studied problem and there exists a large body of literature (e.g., [13,14,18,31]), and there also exist distributed computing approaches [16] and online algorithms [5,11]. Our work is orthogonal to this line of literature in the sense that we assume that an (arbitrary and not necessarily resource-optimal) embedding algorithm is given.…”

Energy efficient virtual network embedding for green data centers using data center topology and future migration

“…The authors formulated the problem as integer linear programming formulations and designed a greedy randomized algorithm to solve it. Fuerst et al [29] proposed a pre-cluster method to partition a virtual network into clusters. In this method, multiple virtual nodes within one VN are mapped to the same physical node if there are enough available resources, so that the traffic inside a VN could be minimized.…”