Myung Ki Shin

Mobility management for all-IP mobile networks: mobile IPv6 vs. proxy mobile IPv6

Recently, a network-based mobility management protocol called Proxy Mobile IPv6 (PMIPv6) is being actively standardized by the IETF NETLMM working group, and is starting to attract considerable attention among the telecommunication and Internet communities. Unlike the various existing protocols for IP mobility management such as Mobile IPv6 (MIPv6), which are host-based approaches, a network-based approach such as PMIPv6 has salient features and is expected to expedite the real deployment of IP mobility management. In this article, starting by showing the validity of a network-based approach, we present qualitative and quantitative analyses of the representative host-based and network-based mobility management approaches (i.e., MIPv6 and PMIPv6), which highlight the main desirable features and key strengths of PMIPv6. Furthermore, a comprehensive comparison among the various existing well-known mobility support protocols is investigated. Although the development of PMIPv6 is at an early stage yet, it is strongly expected that PMIPv6 will be a promising candidate solution for realizing the next-generation all-IP mobile networks.

Handover Latency Analysis of a Network-Based Localized Mobility Management Protocol

Recently, the IETF NETLMM working group is standardizing a network-based localized mobility management (NETLMM) protocol called proxy mobile IPv6 (PMIPv6), yet the research on NETLMM is still in its early stage while it has attracted a fair amount of critical attention both in the telecommunication and the Internet communities. Unlike previous host-based mobility management protocols such as mobile IPv6 (MIPv6), hierarchical mobile IPv6 (HMIPv6), and fast handover for mobile IPv6 (FMIPv6), PMIPv6 has salient features and is expected to expedite the real deployment of IP mobility support protocol by using only collaborative operations between the network entities without mobile node (MN) being involved. In this paper, we analyze and compare the handover latency of PMIPv6 with those of the various existing host-based IP mobility management protocols. In addition, we show good efficacy of the desirable features and key strengths of PMIPv6. Numerical results demonstrate that (1) the handover latency of PMIPv6 is much lower than those of MlPv6 and HMIPv6, and (2) the handover latency of PMIPv6 becomes lower than that of FMIPv6 in case the wireless link delay is greater than the delay between mobile access gateway (MAG) and local mobility anchor (LMA).

Application translation for IPv6 at NAT-PT

The next generation Internet protocol, IPv6 which uses 128 bits Internet addresses will replace the current IPv4 protocol gradually from 2005. After 2010 IPv6 will be the main ocean of Internet or network. But until completely transition to IPv6, IPv4 and IPv6 will coexist and network devices must support IPv4 and IPv6 at the same time. Especially general users want to use Internet and applications without big changes even if networks are changed to IPv6. This paper describes ALG (application layer gateway) for IPv6 which translates application layer data in NAT-PT transition mechanism. With the design and implementation of DNS-ALG and FTP-ALG, we research the application layer gateway and examine the relationship between IP layer translation and application layer translation. As IPv6 is more deployed, not only IP layer translation, but also application layer translation has more necessity.

Optimal network resource utilization in service function chaining

Service function chaining (SFC) refers to as an order set composed of multiple service functions (SFs) that specific flows should be processed. In this paper, we formulate an optimization problem to efficiently utilize the network resource in SFC-enabled networks by determining the amount of flows assigned to each link and SF instance. Simulation results demonstrate that the proposed optimal solution can reduce the network resource usage and thus accommodate more flows compared with non-optimal solutions.

Verification for NFV-enabled network services

Network Functions Virtualization (NFV) offers a new way to design, deploy and manage network services. NFV relocates network functions from dedicated hardware appliances to generic servers, so they can run in software. Also, it is designed to consolidate and deliver the network components needed to support a virtualized infrastructure including virtual servers and storage, as well as networks. However, incomplete or inconsistent configuration of virtualized network functions (VNF) and forwarding graph (FG, aka service chain) could cause breakdown of the supporting infrastructure. Moreover, automation of NFV process with integration of Software-Defined Networking (SDN) technologies may lead the network services to be more error-prone. Recognizing these problems, we need to identify key properties to be checked. In this article, we present a framework of verification for NFV-enabled network services. Its goal is to provide a formal method for the network services that can be used to build and verify NFV components. Overall, this method makes it safer and more reliable for network operators to compose their network services in NFV environment, so that they can be assured that the properties are correctly enforced.

Process Algebraic Specification of Software Defined Networks

In this paper, we first present a formal specification for a part of Software Defined Networks(SDN) using a process algebra called Algebra of Communicating Shard Resources(ACSR). To provide a correct and efficient solution for forwarding packets on the Software Defined Networks, ACSR can express processes running concurrently and communicating switches and a controller. Forwarding packets can be modeled as prioritized synchronization of events in ACSR. During specifying formally, we could find the Subtle Ambiguity in the SDN specification. The central contribution of this paper is to describe how to apply a formal specification method to a part of informal SDN specification. It is important to specify SDN and verify the properties of the SDN using formal specification before implementing the systems. Furthermore, we prove the correctness of ACSR specification to show deadlockfreeness using VERSA.

Service function path adaptation in SFC

This paper proposes a service function path adaptation capability in service function chaining. This capability creates and dynamically adapts service function paths to optimize performance of the overall network service along the service function chain. This paper presents problem definition, the corresponding use cases, and design considerations of the control plane architecture of service function chaining for the service function path adaptation capability.

The Performance Analysis of NAT-PT and DSTM for IPv6 Dominant Network Deployment

NAT-PT and DSTM are becoming more widespread as de-facto standards for IPv6 dominant network deployment. But few researchers have empirically evaluated their performance aspects. In this paper, we compared the performance of NAT-PT and DSTM with IPv4-only and IPv6-only networks on user applications using metrics such as throughput, CPU utilization, round-trip time, and connect/request/response transaction rate.