Bohao Feng

SAT-GRD: An ID/Loc split network architecture interconnecting satellite and ground networks

Since the satellite network plays an irreplaceable role in many fields, how to interconnect it with the ground network has received an unprecedented attention. However, with much more requirements imposed to the current terrestrial network, many serious problems caused by the IP dual-role exposed. In this context, their direct interconnection seems not the most appropriate way. Thus, in this paper, SAT-GRD, an incrementally deployable ID/Loc split network architecture is proposed, aiming to integrate the satellite and ground networks efficiently. Specifically, SAT-GRD separates the identity of both the host and network from the location. Then, it isolates the host from the network, and further divides the whole network into core and edge networks. These make SAT-GRD much more flexible and scalable to achieve heterogeneous network convergence and avoid problems resulting from the overloaded semantics of IP addresses. In addition, much work has been done to implement the proof-of-concept prototype of SAT-GRD, and experimental results prove its feasibility.

Cache-Filter : A Cache Permission Policy for Information-Centric Networking

Information Centric Networking (ICN) has recently attracted great attention. It names the content decoupling from the location and introduces network caching, making the content to be cached anywhere within the network. The benefits of such design are obvious, however, many challenges still need to be solved. Among them, the local caching policy is widely discussed and it can be further divided into two parts, namely the cache permission policy and the cache replacement policy. The former is used to decide whether an incoming content should be cached while the latter is used to evict a cached content if required. The Internet is a user-oriented network and popular contents always have much more requests than unpopular ones. Caching such popular contents closer to the user’s location can improve the network performance, and consequently, the local caching policy is required to identify popular contents. However, considering the line speed requirement of ICN routers, the local caching policy whose complexity is larger than O(1) cannot be applied. In terms of the replacement policy, Least Recently Used (LRU) is selected as the default one for ICN because of its low complexity, although its ability to identify the popular content is poor. Hence, the identification of popular contents should be completed by the cache permission policy. In this paper, a cache permission policy called Cache-Filter, whose complexity is O(1), is proposed, aiming to store popular contents closer to users. Cache-Filter takes the content popularity into account and achieves the goal through the collaboration of on-path nodes. Extensive simulations are conducted to evaluate the performance of Cache-Filter. Leave Copy Down (LCD), Move Copy Down (MCD), Betw, ProbCache, ProbCache+, Prob(p) and Probabilistic Caching with Secondary List (PCSL) are also implemented for comparison. The results show that Cache-Filter performs well. For example, in terms of the distance to access to contents, compared with Leave Copy Everywhere (LCE) used by Named Data Networking (NDN) as the permission policy, Cache-Filter saves over 17% number of hops.

Locator/Identifier Split Networking: A Promising Future Internet Architecture

The Internet has achieved unprecedented success in human history. However, its original design has encountered many challenges in the past decades due to the significant changes of context and requirements. As a result, the design of future networks has received great attention from both academia and industry, and numerous novel architectures have sprung up in recent years. Among them, the locator/identifier (Loc/ID) split networking is widely discussed for its decoupling of the overloaded IP address semantics, which satisfies several urgent needs of the current Internet such as mobility, multi-homing, routing scalability, security, and heterogeneous network convergence. Hence, in this paper, we focus on Loc/ID split network architectures, and provide a related comprehensive survey on their principles, mechanisms, and characteristics. First, we illustrate the major serious problems of the Internet caused by the overloading of IP address semantics. Second, we classify the existing Loc/ID split network architectures based on their properties, abstract the general principle and framework for each classification, and demonstrate related representative architectures in detail. Finally, we summarize the fundamental features of the Loc/ID split networking, compare corresponding investigated architectures, and discuss several open issues and opportunities.

EmuStack: An OpenStack-Based DTN Network Emulation Platform (Extended Version)

With the advancement of computing and network virtualization technology, the networking research community shows great interest in network emulation. Compared with network simulation, network emulation can provide more relevant and comprehensive details. In this paper, EmuStack, a large-scale real-time emulation platform for Delay Tolerant Network (DTN), is proposed. EmuStack aims at empowering network emulation to become as simple as network simulation. Based on OpenStack, distributed synchronous emulation modules are developed to enable EmuStack to implement synchronous and dynamic, precise, and real-time network emulation. Meanwhile, the lightweight approach of using Docker container technology and network namespaces allows EmuStack to support a (up to hundreds of nodes) large-scale topology with only several physical nodes. In addition, EmuStack integrates the Linux Traffic Control (TC) tools with OpenStack for managing and emulating the virtual link characteristics which include variable bandwidth, delay, loss, jitter, reordering, and duplication. Finally, experiences with our initial implementation suggest the ability to run and debug experimental network protocol in real time. EmuStack environment would bring qualitative change in network research works.

Fuzzy Theory Based Security Service Chaining for Sustainable Mobile-Edge Computing

Mobile-Edge Computing (MEC) is a novel and sustainable network architecture that enables energy conservation with cloud computing and network services offloading at the edge of mobile cellular networks. However, how to efficiently manage various real-time changing security functions is an essential issue which hinders the future MEC development. To address this problem, we propose a fuzzy security service chaining approach for MEC. In particular, a new architecture is designed to decouple the required security functions with the physical resources. Based on this, we present a security proxy to support compatibility to traditional security functions. Furthermore, to find the optimal order of the required security functions, we establish a fuzzy inference system (FIS) based mechanism to achieve multiple optimal objectives. Much work has been done to implement a prototype, which is used to analyze the performance by comparing with a widely used method. The results prove that the proposed FIS mechanism achieves an improved performance in terms of Inverted Generational Distance (IGD) values and execution time with respect to the compared solution.

HetNet: A Flexible Architecture for Heterogeneous Satellite-Terrestrial Networks

As satellite networks have played an indispensable role in many fields, how to integrate them with terrestrial networks (e.g., the Internet) has attracted significant attention in academia. However, it is challenging to efficiently build such an integrated network, since terrestrial networks are facing a number of serious problems, and since they do not provide good support for heterogeneous network convergence. In this article, we propose a flexible network architecture, HetNet, for efficient integration of heterogeneous satellite-terrestrial networks. Specifically, the HetNet synthesizes Locator/ID split and Information-Centric Networking to establish a general network architecture. In this way, it is able to achieve heterogeneous network convergence, routing scalability alleviation, mobility support, traffic engineering, and efficient content delivery. Moreover, the HetNet can further improve its network elasticity by using the techniques of Software-Defined Networking and Network Functions Virtualization. In addition, to evaluate the HetNet performance, we build a proof-of-concept prototype system and conduct extensive experiments. The results confirm the feasibility of the HetNet and its advantages.

EmuStack: An OpenStack-Based DTN Network Emulation Platform

The paper presents EmuStack, a large-scale, real-time and distributed emulation platform for Delay Tolerant Network (DTN). Based on OpenStack, EmuStack can implement synchronous, dynamical and precise control of link characteristics and topology, and can support a large-scale emulation including hundreds of nodes via several hosts. In this paper, we firstly describe hardware and software architecture of EmuStack, and then introduce the core modules and algorithm. Finally, we evaluate and demonstrate EmuStack by reproducing key results from a published DTN experiment.

A Popularity-Based Cache Consistency Mechanism for Information-Centric Networking

Information-Centric Networking (ICN) has emerged as a promising way for the efficient content delivery over the Internet, and it can be seen as a super large-scale caching distributed system. However, as one of the most important problems, the cache consistency issue, which refers to whether cached contents in routers are outdated, is still not investigated thoroughly in ICN. Thus, in this paper, we propose a cost-effective Popularity-based Cache Consistency (PCC) mechanism to guarantee the freshness of cached contents in ICN routers. PCC is able to balance the trade between the consistency strength and related costs since it only maintains the strong consistency for popular contents while the weak for unpopular ones. Besides, we improve another two cache consistency mechanisms used in the web caching, namely Polling-Every-Time (PET) and Time-To-Live (TTL), to be suitable for ICN, and use them as the benchmarks for comparisons with PCC. To evaluate their performance, we firstly analyse the costs of these mechanisms including the user latency in terms of hop counts and corresponding signaling overheads, and then conduct extensive simulations using a real topology. The simulation results show the high efficiency of PCC compared with the improved PET and TTL.

Least Popularly Used: A Cache Replacement Policy for Information-Centric Networking

The local caching policy of nodes is always one of the hottest issues in caching networks. It can be further divided into two branches, the decision policy and the replacement policy. In this paper, a replacement policy named Least Popularly Used (LPU) is proposed for cache nodes in Information-Centric Networking (ICN) to improve the network performance. Both the request number and the arrival time of a content are taken into account in LPU for judging content popularity. Thus, recently popular contents are cached near consumers, reducing the consumers’ distance to access contents and the traffic load on the original sever. Based on the string, tree and ISPlike topology, extensive simulations are performed, and the results indicate that the performance of LPU is better than that of other replacement policies, including Most Recently Used (MRU), Least Recently Used (LRU), Random, Greedy Dual-Size (GDS), Most Frequently Used (MFU), Least Frequently Used (LFU) and LFU-Dynamic Aging (LFU-DA), in terms of the average hop counts, the server hit ratio and the cache eviction counts.