VNF Placement for Service Function Chains with Strong Low-Delay Restrictions in Edge Computing Networks

Abstract

The edge computing paradigm, allowing the location of network services close to end users, defines new network scenarios. One of them considers the existence of micro data centers, with reduced resources but located closer to service requesters, to complement remote cloud data centers. This hierarchical and geo-distributed architecture allows the definition of different time constraints that can be taken into account when mapping services into data centers. This feature is especially useful in the Virtual Network Function (VNF) placement problem, where the network functions composing a Service Function Chain (SFC) may require more or less strong delay restrictions. We propose the ModPG (Modified Priority-based Greedy) heuristic, a VNF placement solution that weighs the latency, bandwidth, and resource restrictions, but also the instantiation cost of VNFs. ModPG is an improved solution of a previous proposal (called PG). Although both heuristics share the same optimization target, that is the reduction of the total substrate resource cost, the ModPG heuristic identifies and solves a limitation of the PG solution: the mapping of sets of SFCs that include a significant proportion of SFC requests with strong low-delay restrictions. Unlike PG heuristic performance evaluation, where the amount of SFC requests with strong low-delay restrictions is not considered as a factor to be analyzed, in this work, both solutions are compared considering the presence of 1%, 15%, and 25% of this type of SFC request. Results show that the ModPG heuristic optimizes the target cost similarly to the original proposal, and at the same time, it offers a better performance when a significant number of low-delay demanding SFC requests are present.

An online service function chain orchestration method for profit maximization in edge computing networks

“…An efficient polynomial time heuristic algorithm was used to solve the optimization problem. Lopezp et al 18 proposed a modified priority‐based greedy heuristic algorithm to weight the latency, bandwidth, resource restrictions and instantiation cost of VNFs. Manzalini et al 19 thought that softwarization was a systemic transformation and proposed an edge operating system combining SDN, NFV and cloud and edge‐fog computing.…”

Service function chain composition and placement using grammar‐based genetic algorithm

“…ModPG was an improved solution of a previous proposal (called PG). 16 Guo et al considered the offline deployment issue from sharing VNF instances to improve resource utilization and reduce total placement costs.…”

Special Issue: Novel Algorithms and Protocols for Networks

“…Manzanares-Lopez et al [6] contribute to this special issue with a paper dealing with the Virtual Network Function (VNF) placement problem in Micro Data Center (MDC)/Cloud Data Center (CDC) edge computing networks. In particular, the authors propose a VNF placement solution that takes into account the latency and resource requirements imposed by the service function chains (SFC), the bandwidth and resource restrictions imposed by the network and micro data centers, and the instantiation cost of VNFs.…”