高可用性SIP網路中無單點失效的整合代理/註冊伺服器之設計與實現

Abstract

SIP目前被應用在許多網路服務，如網路電話或IP多媒體子系統服務。在一個高可用性的SIP網路中，SIP代理伺服器和SIP註冊器都是相當重要的元件。在這篇論文中，我們設計並且實作了一個沒有單點失效的整合SIP代理/註冊伺服器(IPRS)，以建構一個高可用性的SIP網路。我們將使用者資訊存在每台SIP代理/註冊伺服器的記憶體中，而不是存在一個獨立的資料庫裡。IPRS提出的 ”n + m” 整合SIP代理/註冊伺服器是由 n 個使用中的SIP代理/註冊伺服器和 m 個備援的SIP代理/註冊伺服器所組成。每個使用中的SIP代理/註冊伺服器可以經由OpenAIS的服務換手到備援的SIP代理/註冊伺服器。實作測量的結果顯示，在呼叫頻率為每秒四百個連線時，IPRS因為使用中的SIP代理/註冊伺服器失效而產生的失效呼叫數目比PPDR減少了百分之五十六。

SIP (session initiation protocol) has been applied to many services, such as VoIP and IP multimedia subsystem (IMS). The SIP proxy server and SIP registrar play an important role in high availability SIP networks. In this thesis, we propose and implement a high availability SIP network architecture that deploys integrated proxy/registrar servers (IPRSs) with no single point of failure problem (SPOF). It stores each user agent’s (UA’s) information in the memory of each active proxy/registrar server rather in a separate database. The “n + m” architecture consists of n active SIP proxy/registrar servers and m standby SIP proxy/registrar servers to process SIP messages from UAs. Each active proxy/registrar server may failover to a standby proxy/registrar using the services of OpenAIS. Experimental results show that when an active SIP proxy/registrar server fails, the number of failed calls in the proposed IPRS is 56% smaller than that of PPDR, a related work with a database involved, under a call rate of 400 calls/per second.