Yifeng Zhong

Routing on demand: toward the energy-aware traffic engineering with OSPF

Energy consumption has already become a major challenge to the current Internet. Most researches aim at lowering energy consumption under certain fixed performance constraints. Since trade-offs exist between network performance and energy saving, Internet Service Providers (ISPs) may desire to achieve different Traffic Engineering (TE) goals corresponding to changeable requirements. The major contributions of this paper are twofold: 1) we present an OSPF-based routing mechanism, Routing On Demand (ROD), that considers both performance and energy saving, and 2) we theoretically prove that a set of link weights always exists for each trade-off variant of the TE objective, under which solutions (i.e., routes) derived from ROD can be converted into shortest paths and realized through OSPF. Extensive evaluation results show that ROD can achieve various trade-offs between energy saving and performance in terms of Maximum Link Utilization, while maintaining better packet delay than that of the energy-agnostic TE.

A Model Approach to the Estimation of Peer-to-Peer Traffic Matrices

Peer-to-Peer (P2P) applications have witnessed an increasing popularity in recent years, which brings new challenges to network management and traffic engineering (TE). As basic input information, P2P traffic matrices are of significant importance for TE. Because of the excessively high cost of direct measurement, many studies aim to model and estimate general traffic matrices, but few focus on P2P traffic matrices. In this paper, we propose a model to estimate P2P traffic matrices in operational networks. Important factors are considered, including the number of peers, the localization ratio of P2P traffic, and the network distance. Here, the distance can be measured with AS hop counts or geographic distance. To validate our model, we evaluate its performance using traffic traces collected from both the real P2P video-on-demand (VoD) and file-sharing applications. Evaluation results show that the proposed model outperforms the other two typical models for the estimation of the general traffic matrices in several metrics, including spatial and temporal estimation errors, stability in the cases of oscillating and dynamic flows, and estimation bias. To the best of our knowledge, this is the first research on P2P traffic matrices estimation. P2P traffic matrices, derived from the model, can be applied to P2P traffic optimization and other TE fields.

Exploring the policy selection of the P2P VoD system: A simulation-based research

The P2P-based video-on-demand (P2P VoD) service has achieved tremendous success among Internet users, and attracted many researchers’ interest. Piece selection policy, peer selection policy and replica management policy are three important policies in P2P VoD systems. Although there has been some research work on the policy selection of the P2P VoD system, it still remains unknown that which policy composition is better for the system. Different from the existing research, we study the existing P2P VoD policies by using a simulation framework to understand the features as well as the performance of different policy compositions. The simulation results indicate that when the bandwidth and storage resources are limited in the P2P VoD system, the composition of the sequential piece selection policy, the cascading peer selection policy and the proportional replica management policy has the best performance among all the different policy compositions. However, when the bandwidth and storage resources are sufficient in the system, there will be little difference between different policies. To further understand such a system, we also explore the impact of resources on policies selection. Our simulation provides evidence that theoretically the P2P VoD system can work well without extra replica space as long as the bandwidth of the peers is large enough, but the extra storage space can help improve the performance of the system in practical scenarios where the peers’ bandwidth is limited.

Towards evolvable Internet architecture-design constraints and models analysis

There is a general consensus about the success of Internet architecture in academia and industry. However, with the development of diversified application, the existing Internet architecture is facing more and more challenges in scalability, security, mobility and performance. A novel evolvable Internet architecture framework is proposed in this paper to meet the continuous changing application requirements. The basic idea of evolvability is relaxing the constraints that limit the development of the architecture while adhering to the core design principles of the Internet. Three important design constraints used to ensure the construction of the evolvable architecture, including the evolvability constraint, the economic adaptability constraint and the manageability constraint, are comprehensively described. We consider that the evolvable architecture can be developed from the network layer under these design constraints. What’s more, we believe that the address system is the foundation of the Internet. Therefore, we propose a general address platform which provides a more open and efficient network environment for the research and development of the evolvable architecture.

Can P2P Technology Benefit Eyeball ISPs? A Cooperative Profit Distribution Answer

Peer-to-Peer (P2P) technology has been promoting the development of Internet applications, like Video on Demand (VoD) and file sharing. However, under the traditional pricing mechanism, the fact that most P2P traffic flows among peers can dramatically decrease the profit of ISPs, who may take actions against P2P and impede the adoption of P2P-assisted applications. So far, there is no proper profit distribution mechanism to solve this problem. In this paper, we develop a mathematical framework to analyze such economic issues. Inspired by the idea from cooperative game theory, we propose a cooperative profit-distribution model based on Nash Bargaining Solution (NBS), in which both eyeball ISPs and Peer-assisted Content Providers (PCPs) form coalitions and compute a fair Pareto point to determine profit distribution. Moreover, we design a fair and feasible mechanism for profit distribution within each coalition and give a model to discuss the potential competition among ISPs. We show that such a cooperative method not only guarantees the fair profit distribution among network participants, but also improves the economic efficiency of the network system; and the potential competition among ISPs will make the network more efficient. This paper systematically studies solutions to unbalanced profit distribution caused by P2P and presents a feasible cooperative method to increase and fairly distribute the profit.

Will the three-network convergence happen? — An evolution model based analysis

Three-Network Convergence” refers to the way the telecommunications network, the TV broadcasting network, and the Internet converge and develop together, connecting the three networks and sharing their resources in the provisioning of Internet access, TV, and telephone services. A related term “triple play service” refers to the provisioning of the three services over a single broadband connection. The three-network convergence has been proposed for several years but has not yet been completed. The lack of quantitative analysis on network competitions results in difficulties in comparing different convergence proposals and reaching a consensus. To this end, this paper generalizes the current methods for modeling network evolution, and presents a roadmap for the study of the convergence issue with mathematical modeling. Then it examines the core features of the three networks, and finds the functional relationship between network cost and network user volume. Based on the relationship, it builds a three-network convergence evolution model. Finally, numerical calculations are performed by using estimated parameters and several groups of parameters within reasonable limits, and a number of interesting conclusions are drawn. The results show that (1) the convergence process requires additional impetus; (2) it is quite feasible to stimulate the process through financial investment; and (3) after the process is finished, overall network costs will be reduced.

Cooperative Game-Based Pricing and Profit Distribution in P2P Markets

Peer-to-Peer (P2P) technology has been the foundation of many important Internet applications, like Video on Demand (VoD) and file sharing. However, under the traditional pricing mechanism, the fact that most P2P traffic flows among peers can dramatically decrease the profit of ISPs, who may take actions against P2P and impede the development of P2P technology. In this chapter, we develop a mathematical framework to analyze such economic issues. Inspired by the idea from cooperative game theory, we propose a cooperative profit-distribution model based on Nash Bargaining Solution (NBS), in which both eyeball ISPs and Peer-assisted Content Providers (PCPs) form a separate coalition and compute a fair Pareto point to determine profit distribution. Here the eyeball ISPs refer to the ISPs which specialize in delivery to hundreds of thousands of residential users, supporting the last-mile connectivity [8]. Moreover, we design a fair and feasible mechanism for profit distribution within each coalition and give a model to discuss the potential competition among ISPs. We show that such a cooperative method not only guarantees the fair profit distribution among network participators, but also helps improve the economic efficiency of the network system.

Performance and incentive of teamwork-based channel allocation in spectrum access networks

Recent years have witnessed the great popularity of dynamic spectrum access networks. Such an approach is adopted between three players: government, Internet Service Providers (ISPs) and end-users. ISPs need to purchase spectrum from the government before subletting it to end-users, but currently most researches focus on the subletting process and ignore the purchasing process. In this paper, we try to investigate the game between government and ISPs in spectrum access networks. In this framework, the former aims to optimize user experience yet the later want to maximize their own profits. Such a conflict of interests introduces significant challenges to ensure end-users performance and thus leads to a severe bottleneck to the spectrum access networks. Inspired by cooperative trends among users, we proposed a novel Channel Allocation model based on Teamwork (CAT). This approach considers both ISPs respective bands and end-users experience and enables a smart profit sharing algorithm to address the problem. The evaluation results indicate that CAT improves the overall social welfare by about 30% than the Vickrey Clarke Groves (VCG) mechanism and obtains higher stability.

Pricing and Management Related to P2P and Mobile Internet

With the rapid development of the Internet, the amount and types of network applications have increased significantly, and hence the traffic. On the other hand, consumer’s demand for network resources is also becoming more and more intense. Although easy to implement, the traditional flat pricing makes the utilization rate of network resources drop significantly. Especially since the appearance of new network applications like P2P, the cost of network operation has soared, while the profit of ISPs has decreased notably. As a countermeasure, many ISPs, such as AT&T, Verizon and Comcast have abandoned the traditional flat pricing and adopted the traffic-based hierarchical pricing method instead [43] [Shen, S. IEEE Commun. Mag. 50(11):91–99]. which has thus become a hot topic. At the same time, as the Internet market has become more mature, the competition between ISPs and content providers (CPs) have been brought into full play. Therefore, games appear frequently in resource pricing analyses.

Pricing in Multi-Interface Wireless Communication Markets

This chapter focuses on the dynamic game relationship in the Internet service market, where ISPs provide services and multi-interface mobile users select services. Through the modeling of the Internet service market, service composition and the users, the bargaining in the exclusive monopoly market and the dynamic game procedure in the oligopoly market were analyzed by using the non-cooperative game theory.