本文介紹了軟交換系統(tǒng)分布式呼叫服務(wù)器 (Call Server，簡(jiǎn)稱(chēng)CS)中SIP協(xié)議DNS的實(shí)現(xiàn)，討論了支持DNS域名對(duì)系統(tǒng)的影響及需求，分析了分布式CS如何支持對(duì)端SIP實(shí)體以
域名呈現(xiàn)，以及其如何支持以域名呈現(xiàn)給對(duì)端SIP實(shí)體。軟交換系統(tǒng)通過(guò)對(duì)DNS域名的支持，CS不僅能和以域名方式呈現(xiàn)的其他SIP實(shí)體互通，更重要的通過(guò)以DNS域名方式呈現(xiàn)給其SIP實(shí)體，一個(gè)CS或者多個(gè)CS組成一個(gè)DNS域，簡(jiǎn)化了網(wǎng)絡(luò)，提高了系統(tǒng)的可靠性。
關(guān)鍵詞：SIP，DNS，分布式呼叫服務(wù)器
Abstract: This paper gives an introduction of the design and realization of SIP DNS in the call
server based on soft switch system. It not only discusses the influence to the existed system for supporting DNS，but also analyses how to support DNS of SIP entity. Due to supporting DNS in the system, CS not only can communicate with other SIP entity through domain name. But also can present itself through domain name. More than one CS forms a DNS domain, so the network is simplified and the system is more reliable.
Key words: SIP，DNS，CS