IP多媒體系統過渡閘道之IPv4-IPv6轉換效能分析

Abstract

3GPP (Third-Generation Partnership Project) 規定IP多媒體子系統 (IP Multimedia Core Network Subsystem) 使用IPv6 (Internet Protocol version 6) 通訊協定。但在IPv6環境佈建之初，IP多媒體子系統仍須與舊有使用IPv4 (Internet Protocol version 4) 通訊協定之VoIP (Voice over IP) 網路進行互通。3GPP 提出IMS-ALG (IMS-Application Level Gateway) 和TrGW (Transition Gateway) 兩個元件，分別提供SIP (Session Initiation Protocol) 訊息以及RTP (Real-time Transport Protocol) 封包之IPv4-IPv6轉換。本論文研發NICI (National Information and Communications Initiative)-TrGW以增進TrGW轉換RTP封包之效能，並使用SmartBits對NICI-TrGW和現有的TrGW實作 (Naptd-TrGW與Portaone-TrGW) 進行效能實測。根據實際效能測試的結果，NICI-TrGW在封包遺失率、最大吞吐量與平均延遲等測試項目上之效能均優於現有之實作。

Internet Protocol version 6 (IPv6) is adopted by Third-Generation Partnership Project (3GPP) to provide large address space for IP Multimedia Core Network Subsystem (IMS). However, in the early stage of IPv6 deployment, the existing Voice-over-IP (VoIP) networks support Internet Protocol version 4 (IPv4) only. For IPv4-IPv6 interworking between IMS and the existing VoIP networks, the IMS-Application Level Gateway (IMS-ALG) and the Transition Gateway (TrGW) are proposed to translate Session Initiation Protocol (SIP) and Real-time Transport Protocol (RTP) packets, respectively. In this thesis, we focus on the IPv4-IPv6 translation for RTP packets, which is the bottleneck of VoIP performance. Specifically, we developed a TrGW called National Information and Communications Initiative (NICI)-TrGW, and evaluate the performance of NICI-TrGW and the existing solutions (i.e., Portaone-TrGW and Naptd-TrGW) by using the SmartBits. Our study indicates that NICI-TrGW outperforms the existing solutions in terms of three different output measures including packet loss rate, maximum throughput, and average latency.