For cloud providers, it is essential to improve the quality of service that depends on the failure probability of protection and the computing capacity cost such as backup resources. Existing studies addressed a protection approach to reduce the required ...

This paper proposes a polynomial-time algorithm for a server allocation problem in delay-sensitive Internet-of-Things (IoT) monitoring services. The server allocation problem determines the appropriate servers to which the database and ...

This paper proposes a backup computing and transmission capacity allocation model for virtual networks that minimizes the required backup computing capacity under multiple facility node failures. The proposed model adopts the probabilistic protection, ...

Inter-core crosstalk (Ic-Xt) and inter-mode crosstalk (Im-Xt) occur during the transmission of optical signals through multi-core multi-mode fibers in spectrally-spatially elastic optical networks (SS-EONs), which degrade the signal quality. Xt-...

Service chaining provides network services to users by processing packets with a series of virtualized network functions (VNFs). Multicast communication can suppress the network load compared to unicast communication when the same service is ...

Cloud service providers widely use virtual machines and bring various benefits for customers and themselves. The unavailability of virtual machines is a crucial performance indicator for cloud service quality. However, no previous works studied ...

In network function virtualization, virtual network functions (VNFs) are usually chained in specific orders to generate service function chains (SFCs). Recently, SFC parallelism has been presented to enable VNFs to run in parallel to reduce the end-to-end ...

Recently, multi-core fiber (MCF) has been incorporated with elastic optical networks (EONs) to enhance the fiber capacity, which forms spectrally-spatially EONs (SS-EONs). In MCF, inter-core crosstalk (XT) occurs and degrades the signal quality. ...

Multi‐access edge computing (MEC) enables users to exploit the resources of cloud computing at a base station (BS) in proximity to the users where an MEC server is hosted. While we have advantage of being able to communicate with low latency and ...

We propose a service placement and user assignment model with preventive start‐time optimization in multi‐access edge computing (MEC) networks to enhance the system reliability, which preventively determines the service placement and user assignment in ...

Network function virtualization (NFV) implements network functions as software, which enables flexible, resource‐efficient, and rapid provision of network services. In NFV, network services are realized by the service function chain (SFC), which ...

We propose a virtual network function (VNF) placement model on a per‐VNF instance basis that considers the availability of the service function chain (SFC). We develop an availability computation method with reduced computation time using a ...

This Special Section features research contributions in the area of robust and reliable networks of the future. Modern network infrastructures must support a growing demand for intensive data processing and high-speed communication, that has led, in the ...

This paper proposes a preventive priority setting model to minimize the worst-case maximum utilization ratio against multiple controller failures in software defined networks. For a set of controllers able to manage a switch, we introduce a priority for ...

Modern network services and functions, such as firewalls, load balancers, and network address translators, are virtualized to virtual network functions (VNFs) and run in virtual machines and containers. This paper proposes a robust VNF ...

Middleboxes work as software which runs on a general-purpose server by adopting network function virtualization. The unavailability of middlebox is a key metric. The previous study considers allocating backup servers to middleboxes to reduce the ...

This paper proposes a controller placement model that takes into account the load-dependent sojourn time at each controller while considering controller failures in a software-defined network. The sojourn time is expressed by the queuing theory. The ...

Network function virtualization enables service providers to flexibly deploy network services. The existing works mainly focus on function placement and capacity allocation without exploring traffic scheduling for service deployment, by adopting a first-...

In a cloud, protection through backup of virtual machines contained in physical machines (PMs) reduces damage to users due to failure of PMs, such as hardware malfunctions. However, from a resource cost perspective, it is necessary to reduce the amount of ...

Service chaining provides network services by flexibly configuring service chains that connect virtualized network functions (VNFs) in the appropriate order so as to satisfy users’ needs. Existing models can be inefficient in terms of consuming ...