In addition to stationary sensors/actuators (nodes), mobile nodes such as vehicles and smartphones are connected to M2M (Machine-to-Machine) systems. Some M2M systems take into account node mobility, while some M2M systems regard vehicles as compute servers. N one of them, however, handle the mobility of nodes that act as compute servers. This paper proposes an MEC (Multi-access Edge Computing) based M2M system called MECM2M, which can handle the mobility of nodes acting as sensors/actuators and compute servers. The design policy of MECM2M is analogous to that of the Internet. The Internet provides two fundamental services: reliable byte stream and unreliable datagram. How data is used is up to applications. MECM2M provides M2M applications with three fundamental services as the M2M services: area-based data acquisition, node-based data acquisition, and node-based action instruction. How sensing data is used is up to M2M applications. MECM2M introduces the virtual nodes as digital twins in the virtual space for the physical nodes. The virtual nodes conceal differences from the physical nodes and provide a uniform interface. The relation among the virtual nodes, the physical nodes, and the locations of the physical nodes is managed by a domain ontology called Onto- Mecm2m,which enables effective processing of the three fundamental services. The evaluation results on an MECM2M emulator show that the response times of the three fundamental services satisfy the latency constraints, i.e., 100 ms, defined in an ETSI (European Telecommunications Standards Institute) document.

In an MEC (Multi-access Edge Computing) environment, it is suitable to compose an application as a set of containers for flexibility in resource allocation. This paper proposes stateless shared containers (SS-Containers) that can be shared by multiple applications simultaneously in an MEC environment, similar to a shared library in an operating system. It is expected that SS-Containers reduce resource consumption, shorten application startup time, and efficiently manage special hardware such as GPU. When 16 applications share an SS-Container with an encryption function, and each application contains the container with the same encryption function, the memory consumption is reduced by approximately 190 MiB. Comparing the case in which nine applications share an SS-Container that accesses a GPU to solve large-scale simultaneous linear equations with the case in which nine applications randomly access a GPU via a container inside them, the response time is reduced approximately by 57 % (39 seconds).

Network Function Virtualization Infrastructure (NFVI) enables the operation of Network Function Chaining (NFC) in a low-cost and flexible manner by realizing network functions as software on general-purpose servers. One of NFVI's security requirements is access control to packet buffers, which can be achieved using Intra-process Isolation techniques. This paper proposes a secure NFVI using Software Fault Isolation (SFI) for access control to packet buffers by inserting bounds check instructions before indirect memory access instructions. The measurement results show that the proposed method is faster than ERIM, another Intra-process isolation method based on domain switching.

In a Multi-access Edge Computing (MEC) environment, an application will be composed of multiple containers running on edge servers, and a container orchestration method determines which containers should be deployed on which edge servers. This paper proposes a container orchestration method considering shared containers. These containers will be introduced in an MEC environment to reduce application resource usage, similar to a shared library in an operating system. The proposed method adopts a multi-stage grouping of edge servers to aggregate computation resource information and network information of the edge servers for efficient orchestration calculation. The formulation of the proposed orchestration method has been successfully completed, marking a significant milestone in this research. Evaluation will be conducted assuming an environment that contains 2,048 edge servers and 200 user terminals.

The number of IoT devices is increasing, but applications that utilize IoT devices and their data are still developing. One reason is the tight coupling between M2M infrastructure and applications and the difficulty of handling mobile devices in a unified manner. To address these challenges, we developed a versatile M2M system called "MECM2M" that utilizes the MEC paradigm. This paper proposes "MECM2Mv2" by adopting the Pub-Sub model and redesigning modules to improve the latency and efficiency, which were issues in MECM2M. Our future research evaluates the safety of using MECM2Mv2 in autonomous driving applications.

As of 2022, 66% of Internet traffic is generated by video services, among which Netflix and YouTube are the dominant players. By monitoring the traffic volume of individual video services, ISPs (Internet Service Providers) can make appropriate capital investments and determine appropriate peering policies with CDN (Content Delivery Network) providers. Although DPI (Deep Packet Inspection) is widely used to identify network services, packet-level analysis does not scale to the traffic passing through backbone ISPs and is inapplicable to encrypted packets. This paper proposes OLIViS (OSINT-based Lightweight method for Identifying Video Services), a flow-level, label-free method designed for backbone ISPs. OLIViS employs a CNN-VAE (Convolutional Neural Network - Variational AutoEncoder) model to initially identify elephant flows which likely include video service flows and then utilizes OSINT (Open Source INTelligence) data for further services identification. Two datasets are used for evaluation: UTMobileNet2021 and WIDE backbone real trace. The evaluation results show that OLIViS identifies the Netflix and YouTube flows with an accuracy of over 96% in terms of traffic volume. Moreover, OLIViS infers the flow statistics (e.g., mean and peak throughput) of Netflix and YouTube, which closely resemble those inferred with DPI on non-encrypted traffic in a campus network.

This paper proposes an architecture called Cont-MEC for enabling UEs (User Equipments) to offload a part of applications to MEC (Multi-access Edge Computing) servers. It is expected that a MEC infrastructure is composed of a small number of centralized data centers and geographically distributed edge stations, in each of which multiple edge servers are installed. It is also expected that applications on UEs are implemented as container clusters similar to cloud-native applications and they are deployed on computing clusters. ContMEC has the following three features: (i) constructing a computing cluster per edge station for scalability to the number of UEs, (ii) hierarchical resource management for scalability and efficient resource sharing among computing clusters, and (iii) overlapped computing clusters for efficient resource sharing. A PoC (Proof-of Concept) implementation of ContMEC employs Kubernetes as a container orchestration system without modifications although Kubernetes does not take account of the MEC infrastructure. The PoC implementation shows that advantage of offloading is larger than disadvantage of implementing applications as container clusters, control traffic is moderate against the number of UEs, and efficient resource sharing among computing clusters is achieved.

Wireless sensor networking is a key enabler of Industrial IoT. IETF (Internet Engineering Task Force) has standardized a protocol suite called 6TiSCH (IPv6 over the TSCH mode of IEEE802.15.4e). 6TiSCH builds an IPv6 multi-hop wireless network with the IEEE802.15.4 radio, which achieves low energy consumption and high reliability. Although network formation time is one of key performance indicators of wireless sensor networks, it has not been studied well with 6TiSCH standard protocols such as MSF (6TiSCH Minimal Scheduling Function) and CoJP (Constrained Join Protocol). In this paper, we propose a scheduling function called SF-Fastboot which shortens network formation time of 6TiSCH. We evaluate SF-Fastboot by simulation comparing with MSF, the state-of-the-art scheduling function. The simulation shows SF-Fastboot reduces network formation time by 41 % – 80 %.

A service in cloud computing is executed in a data center, which may result in large communication delay. To host applications requiring low latency, edge/fog computing has attracted great attention. This paper proposes a mechanism called AFC (Application Function Chaining) for realizing distributed edge/fog computing. In AFC, an application is defined as a Chained-AF, which is composed of one or more AFs (Application Functions) with control structures such as conditional branches. An AF basically fulfills a single task similar to a UNIX command. Thus, a Chained-AF looks like a distributed shell script and the networks look like a single computer from users' viewpoint. A MANO (Management and Network Orchestration) mechanism in AFC places AFs on optimal edge/fog servers which satisfy Chained-AF's requirements when it is launched. Evaluation results of a prototype implementation show that it takes 0.5 seconds and 3 seconds to launch a Chained-AF composed of two and six AFs, respectively, and that the throughput of a Chained-AF is more than 90 % of the line speed, which is independent of the number of AFs. The throughput of an AFC depends on processing performance of AFs, not on the AFC mechanism.

An experimental network environment plays an important role to examine new systems and protocols. We have developed an experimental network construction tool called LiONv1 (Lightweight On-Demand Networking, ver.1). LiONv1 satisfies the following four requirements: programmer-friendly configuration file based on Infrastructure as Code, multiple virtualization technologies for virtual nodes, physical topology conscious virtual node placement, and L3 protocol agnostic virtual networks. None of existing experimental network environments satisfy all the four requirements. In this paper, we develop LiONv2 which satisfies three more requirements: diversity of available network devices, Internet-scale deployment, and disaggregation of network configuration and device configuration. LiONv2 employs NETCONF and YANG to achieve diversity of available network devices and Internet-scale deployment. LiONv2 also defines two YANG models which disaggregate network configuration and device configuration. LiONv2 is implemented in Go and C languages with public libraries for Go. Measurement results show that construction time of a virtual network is irrelevant to the number of virtual nodes if a single virtual node is created per physical node.

In the LTE/LTE-Advanced (LTE-A) system, user-plane for a user equipment (UE) is provided by tunneling which causes header overhead, processing overhead, and management overhead. In addition, the LTE-A system does not support moving cells which are composed of a mobile Relay Node (RN) and UEs attached to the mobile RN. There are several proposals for moving cells in the LTE-A system and the 5G system, however, all of them rely on tunneling for the user-plane, which means that none of them avoid the tunneling overheads. This paper proposes MocLis, a moving cell support protocol based on a Locator/ID split approach. MocLis does not use tunneling. Nested moving cells are supported. Signaling cost for handover of a moving cell is independent of the number of UEs and nested RNs in the moving cell. MocLis is implemented in Linux; user space daemons and modified kernel. The measurement results show that the attachment time and handover time are short enough for practical use. TCP throughput in MocLis is faster than that in the tunneling based approaches.

Recently, applications' demands for the network become more multifaceted. Highly functional application-to- application communication services such as bandwidth aggregation, fault tolerant communication, and delay/disruption tolerant networking (DTN) were developed independently in the network layer, the transport layer, and the application layer. As a result, protocol layering has become complicated. This paper proposes Layer-5 (L5) inserted between the application layer and the trans- port layer to separate communication policies and communication mechanisms to make protocol layering clearer. The transport layer (L4) provides end-to-end communication mechanisms such as reliable byte stream while L5 realizes communication policies such as bandwidth aggregation by combining the communication mechanisms in L4. This paper proposes five types of L5-paths as communication policies: (1) the L5 bundled path for bandwidth aggregation or fault tolerant communication, (2) the L5 spatially- spliced path for communication with middleboxes, (3) the L5 temporally-spliced path for DTN, (4) the L5 spliced- bundled path, and (5) the L5 bundled over spatially-spliced path. An application can select and use an appropriate L5- path depending on the network circumstances through a common API. A prototype of L5 is implemented in the Linux user space as a library to make deployment and maintenance easier. The evaluation shows that establishment time of L5- paths is short enough and performance of L5-paths is comparable or superior to existing technologies.

DTN (Delay/Disruption Tolerant Networking) inserts a new layer between the application layer (L7) and the transport layer (L4) for reliable communication on long-delay, intermittent, or lossy inks. Such a new layer, however, should provide not only a single rich service but also various rich services. We are proposing Layer-5 (L5) inserted between L7 and L4 to provide multiple rich services. One of the rich services of L5 is the L5 temporally-spliced path (L5-TSP). It is an application-to-application path composed of multiple L4 paths, which may not exist at the same time, spliced in L5 in the nodes called splicers. This paper proposes L5-TSP Protocol (L5-TSPP) for reliable communication on lossy links. L5-TSPP places splicers at both ends of a lossy link. It uses TCP on reliable links while UDP on lossy links. It uses partial acknowledgement to enable end nodes to know progress of communication. L5-TSPP is implemented on Linux. It takes 61 msec for connection establishment in L5-TSPP while 530 msec in TCP at packet loss rate of 10 % on a lossy link. It takes 18 sec to send a 1GB file in L5-TSPP while 73 sec in TCP at packet loss rate of 1 %.

Sharing files over the world with higher access throughput and with lower storage cost is a growing demand for the applications that use large files. However, the existing file sharing systems do not realize these two conflicted requests and no research has been found. This paper clarifies the requirements of a global large file sharing system and defines the design goal consisting of three users perspectives: fast retrieving, user defined file availability, and owner-based file management, and one system operators perspective: flexibility in bytes placement. Content Espresso satisfies this goal by approaching with four techniques: three sections model, distributed chunk storage, forward error correction, and UDP retrieving. Content Espresso delivers large files to a client utilizing as much bandwidth as the client access link even servers are located far away from the client.

To overcome MobileIPv6's natural centrality driven single point of failure and redundant routing due to central Home Agent in home network, Global HAHA introduced an overlay of scattered multiple HAs. Placements of secondary HAs were not addressed by major work in existence. This paper analyses placements in ISP's viewpoint at AS level. Freeman's closeness index and betweenness are used in categorizing examined AS level topology of 30, 000 nodes. 30, 000 different random communications were analyzed which substantiated that Freeman's closeness describes topological locations better. Results show that categories having highest, medium indices are tend to hold better performance only when combined with an HA of lowest category. Lowest category shows best performance with the highest category.

To efficiently adapt to dynamically changing network environment such handover and link failure, cross-layer cooperation mechanisms are indispensable. This paper first introduces the following five requirements to cross-layer cooperation architecture through a discussion, (1) cooperation between a layer in a node and a layer (not necessary the same layer) in another node, (2) abstraction of control information, (3) definition of primitives in each layer, (4) availability in a wide area network, and (5) implementation. Although there are a lot of proposals of cross-layer cooperation architecture in the literature, none of them satisfy the five requirements. This paper designs an inter-node cross-layer cooperation architecture called CLINEX (Cross-Layer and Inter-Node information EXchange) so that it satisfies the five requirements. CLINEX is implemented in the user space and the kernel space of Linux. Two scenarios are tested in our test network composed of eight machines. One scenario is congestion detection at a remote node, which results in sending rate control at the end node. Another scenario is link failure detection at a remote node, which results in failover in an SCTP association. The measurement results show that the processing time of CLINEX is negligible in comparison with packet transmission latency.

Heterogeneous network infrastructures have always been part of the public Internet as well as production systems in enterprise and industrial environments. The coexistence of multiple communication technologies and systems from multiple vendors still represents management cost and reliability challenges mainly due to the lack of interoperability at the network management plane. In this paper, we outline the main challenges that organizations face in managing large scale multi-technology and multi-vendor heterogeneous network infrastructures. We then propose the ENM (Extended Network Management) framework, a scalable and extensible service oriented architecture for deploying ontology-driven network management services adapted for large scale heterogeneous infrastructures. The ENM framework defines the different entities involved in deploying ontology-driven network management services and specifies a scalable and flexible communication protocol, based on Diameter (RFC3588), between these entities. To demonstrate the feasibility of the proposed framework, a proof of concept was implemented and deployed on a small scale test-bed.

Recently, it becomes common to handle large files in computers. However, we have a difficulty to realize file sharing over networks, especially for large files. The problem is that we have extended the system model designed decades ago based on a stand-alone computer model. Assuming that all files are located in data centers, and nobody accesses them at the sites, we can redesign the file sharing system model for higher access speed and efficient storage resource usage. We designed a global secure file sharing system called Content Espresso. In this paper, we describe the difficulty, the design goal for global secure file sharing system, and our approach for it. Finally, we explain the impact of Content Espresso on network.

To support mobility, multihoming, routing scalability, and security, there are a lot of proposals based on ID/Locator split approach not only for the current Internet but also for the future Internet. However, none of them meet the requirements for practical operation such as (1) support of heterogeneity of network layer protocols, (2) scalability of ID/Locator mapping system, (3) independence of mapping information management, and (4) avoidance of locator leakage beyond the administrative boundary. This paper proposes a network layer protocol called Z Network Protocol (ZNP) for the future Internet based on clean slate approach. ZNP supports heterogeneity of network layer protocols by "Internetworking with a Common ID Space". Its mapping system meets the requirements (2)-(4) described above. Z Control Message Protocol (ZCMP) is also designed. Currently, implementation of ZNP and ZCMP is ongoing.

Cognitive radio in network core devices such as basestations is being considered as a spectrum management solution for future society's communication demands. Aside from new resource allocation algorithms, efficient inter- and intra-protocol processing should be considered. We propose an opportunistic cross layer architecture called COmmon Layer Architecture (COLA) for information exchange between arbitrary layers for New Generation Networks (NWGN) with network-oriented cognitive radio. Through COLA, information from different protocols, as well as different layers, can be efficiently processed with minimized performance degradation. Emulation and simulation results showed improved aggregate throughput, handoff delay, connectivity and packet drop ratio.

Proxy Mobile IPv6 has been standardized as a network-based mobility management protocol in IETF. To optimize mobile node's handover performance, a context of the mobile node such as its identifier, accounting, authentication and authorization states is expected to be transferred between mobility entities. This paper proposes a simple context transfer mechanism named Context Reflector for Proxy Mobile IPv6 (Context Reflector). Context Reflector carries any kinds of information of mobile nodes. With Context Reflector, the service such as AAA, ROHC and QoS can be quickly re-established after handover of the mobile node. Therefore, the handover latency and the packet loss during handover can be reduced. Comparisons of Context Reflector and other approaches make it clear that Context Reflector is superior in terms of packet loss and handover latency during handover.

The design and implementation of the Virtual Internet Protocol (VIP) are described. The VIP was implemented by modifying an operating system kernel based on 4.3BSD. The overhead of VIP is compared to that of IP. Measured results indicate that VIP can achieve host migration transparency in the Internet with negligible overhead.>

The continued expansion of computer networks and the miniaturization of computers increase the desire to use one's computer in a consistent computational environment, regardless of location and time.In this situation, host migration transparency is very important.This paper introduces a new network architecture which provides host migration transparency in large interconnected networks and proposes a protocol based on the propagating cache method.We introduce the concept virtual network and divide the conventional network layer into two sublayers to realize host migration transparency.Virtual Internet Protocol, or VIP for short, is derived from DARPA-IP as an example of the architecture.We estimate the overhead of VIP.Host migration transparency can be realized without significant processing and traffic overhead.This architecture also preserves host migration transparency across virtual circuits in radio networks.