Multi-Provider Provider Service Chain Embedding With Nestor
Abstract: Network function (NF) virtualization decouples NFs from the underlying middlebox hardware and promotes their deployment on virtualized network infrastructures. This essentially paves the way for the migration of NFs into clouds (i.e., NF-as-a-Service), Service), achieving a drastic reduction of middlebox investment and operational costs for enterprises. erprises. In this context, service chains (expressing middlebox policies in the enterprise network) should be mapped onto datacenter networks, ensuring correctness, resource efficiency, as well as compliance with the provider's policy. The network service embedding (NSE) problem is further exacerbated by two challenging aspects: 1) traffic scaling caused by certain NFs (e.g., caches and WAN optimizers) and 2) NF location dependencies. Traffic scaling requires resource reservations different from the ones specified sp in the service chain, whereas NF location dependencies, in conjunction with the limited geographic footprint of NF providers (NFPs), raise the need for NSE across multiple NFPs. In this paper, we present a holistic solution to the multi-provider multi NSEE problem. We decompose NSE into: 1) NF NF-graph graph partitioning performed by a centralized coordinator and 2) NF NF-subgraph subgraph mapping onto datacenter networks. We present linear programming formulations to derive near near-optimal optimal solutions for both problems. We address the challenging aspect of traffic scaling by introducing a new service model that supports demand transformations. We also define topology abstractions for NF NF-graph graph partitioning. Furthermore, we discuss the