Yoshihiro Nozaki

A tiered addressing scheme based on a floating cloud internetworking model

Scalability in inter-domain routing is becoming stressful as routing table sizes grow at very high rates. In this paper, we present a tiered addressing scheme to be implemented over a Floating Cloud Tiered internetworking model which uses tier based aggregation to address routing scalability. Analysis of the HD-ratio of the addressing scheme and its possible implementation on the AT&T network is presented.

Virtual mobility domains — A mobility architecture for the future Internet

This paper presents a novel mobility architecture called Virtual Mobility Domains that is designed to work with the Floating Cloud Tiered Internetworking model. Virtual Mobility Domains supports both inter Autonomous System (macro) and intra Autonomous System (micro) mobility by leveraging a tiered addressing, a network cloud concept, and a unique packet forwarding scheme introduced by the Floating Cloud Tiered Internetworking model. The proposed mobility architecture is distinct from others by not using IP addressing and classic routing protocols, and deploying user-centric overlapping mobility domains. The comparative simulation study of Virtual Mobility Domains against Mobile IPv6, Hierarchical Mobile IPv6, and Proxy Mobile IPv6 using OPNET shows that Virtual Mobility Domains brings lower latency, lesser signaling overhead, and fewer packets loss during handoffs, specially during inter Autonomous System roaming. The results highlight the potential for a seamless mobility management.

Virtual domains for seamless user mobility

The population of mobile users seeking connectivity to the Internet has been growing over the years, spurred by the capabilities of handsets and the increasing rich Internet content and resources. Mobility management to enable efficient Internet access for users on the move is thus gaining significance. With future Internet design initiatives gaining momentum, it is important that these initiatives consider mobility management as an integral part of the design, keeping in mind that these initiatives also offer the potential for new and novel mobility management schemes. In this article, we introduce the concept of Virtual Mobility Domains (VMD), and describe mobility management using the VMD approach in a newly proposed tiered Internet architecture. The results from a comparative performance study of VMD with mobility management protocols such as Mobile IPv6, Hierarchical Mobile IPv6 and Proxy Mobile IPv6 using simulations show the potential for efficient mobility management under new Internet architectures.

ISP tiered model based architecture for routing scalability

Internet today is faced with problems due to the growing routing table sizes and high churn rates that occur subsequent to changes in routing information. With initiatives for new Internet designs underway, the problem can be addressed through new internetworking models that consider these factors. In this article one such model that is based on the tiered structure of ISPs (used to define their business relationships) is investigated. The model does not use IP and its routing protocols. An analysis of the model applied to the worldwide network of Autonomous Systems (AS) and ISPs shows the significant reduction in routing table sizes and churn rates that can be achieved with the proposed model even under an un-optimized case.

Power Usage Efficiency with a Modular Routing Protocol

Recent years have seen major efforts to contain the environmental footprint of the Internet. The last decade has witnessed revolutionary research to address some of the challenges faced in the Internet. This article describes an investigative framework for determining the energy savings incurred with new routing protocols and routers. The framework is applied to a real ISP network - the AT&T ISP network in the United States. It describes techniques to collect statistics from such large networks and analyze them. The statistics are then used to study the energy consumption in the ISP network both with routers running the current routing protocol, which is Open Shortest Path First (OSPF) and also with routers running the new protocol. The cost models and energy savings studies applied to large ISP networks as presented in this article is the first of its kind. As evidenced from this study significant energy benefits and cost savings thereof can be realized with the proposed modular routing protocol.

Evaluation of tiered routing protocol in floating cloud tiered internet architecture

Abstract Clean slate future Internet initiatives have been ongoing for a few years. An important consideration in the eventual deployment of solutions for such Internet architectures is the testing and validation of the design and its scalability in realistic network environments. Large scale emulation and experimentation testbeds sponsored and funded by major research organizations worldwide provide a suitable platform for the purpose. In this article, we present the implementation details of a new network and routing protocol that entirely replaces IP and its routing protocols from the protocol stack to provide efficient routing and forwarding of packets in a clean slate Floating Cloud Tiered (FCT) Internet architecture. The FCT architecture leverages the tier structure existing among ISPs, and has a new addressing and routing schema based on tiers. In this article, the implementation and evaluation details of the network protocol with these two features, namely the tiered addressing and tier-based routing using the Global Environmental for Network Innovations (GENI) testbed are presented. The performance of the protocol is also compared with Open Shortest Path First (OSPF) implemented over the GENI testbed for identical network topologies.

An analytical model for the Neighbor Turn Taking MAC protocol

The neighbor turn taking (NTT) Medium Access Control (MAC) protocol is a loosely scheduled MAC, whose intended purpose is for use in wireless ad hoc networking environments where the node mobility is low. This protocol has been previously shown via simulation to perform better than IEEE 802.11 in terms of end-to-end packet latency and rate of successfully transmitted packets under saturated conditions. In this paper, we present an analytical model of the NTT MAC based upon the Bianchi station model of 802.11psilas Distributed Coordination Function to further support the claims of previous work. When comparing the analytical model developed for the NTT MAC protocol with that of 802.11, significant improvements in access delay and the probability of successful packet transmission are shown, which will ultimately provide energy savings, while attaining a per node throughput that is consistent with 802.11.

Neighbor Turn Taking MAC - A Loosely Scheduled Access Protocol for Wireless Networks

In this paper a new approach to medium access in a wireless ad hoc network based on neighbor knowledge and their activity is presented. Nodes take turns to transmit based on their neighbors and their transmissions, which reduces the collision probability and avoids the latency due to backoff (and exponential backoff) experienced in random access protocols. The scheme uses features from 802.11 DCF MAC and adopts a loose scheduling approach which is distributed. The performance of this scheme is compared with 802.11 DCF MAC as this is the more popular random access MAC for wireless ad hoc networks.

A Turn Taking Medium Access Protocol for Wireless Ad Hoc Networks

MAC protocols for wireless networks can be broadly categorized as scheduled or random access protocols. Random access protocols continue to be popular for wireless ad hoc networks, because of their robustness and ease of implementation over multihop scenarios. However under heavy traffic load conditions the performance of random access protocol deteriorates and fairness becomes a serious issue. In this paper, we propose a MAC scheme, where nodes take turns to access the media based on local neighbor knowledge and their transmission activity that reduces the impact of random access and ensuing contention resolution leading to exponential backoff and high delays. In the proposed turn taking mechanism the nodes self-schedule in a distributed manner. Through simulations the performance of the neighbor knowledge based turn taking MAC was compared with IEEE 802.11 CSMA/CA (carrier sense multiple access with collision avoidance).

A modular architecture for scalable inter-domain routing

Border Gateway Protocol (BGP) is the de facto standard for inter-domain routing. BGP faces challenges such as increases in routing table size proportional to increases in the number of networks, high convergence times, and high churn rates, among others. Modularity in routing can address several of these challenges. In this article, we discuss a modular routing architecture, its application to the current Internet, and evaluate its scalability in terms of churn rate and routing table size. Optimization opportunities offered by the modular routing architecture are discussed. Briefly, a transition approach to deploy such an architecture, through a Layer 2.5 protocol, is also presented.