摘要
传统的SIP网络组通讯系统大多基于客户机/服务器模型,导致系统可扩展性差,并且由于中央控制服务器到与会节点时延不均衡会造成语音包接收滞后等问题.鉴于此,提出的基于会议管理节点(Conference Management Node,CMN)的组通讯机制有效地解决了上述问题.基于CMN的组通讯机制旨在为每次会议动态找到一个会议管理节点并构建一棵以会议管理节点为根节点的应用层多播树,并采用分域和保持节点间心跳的方式来维护网络节点,准确而实时地收集中继节点信息.组通讯机制采用P2P的方式选取会议管理节点,不依赖于中央控制服务器,增强系统的可扩展性和可靠性;会议管理节点到各个与会成员时延较小(满足通话要求)且时延均衡,改善语音通话质量,防止因时延差异过大而造成的语音接收滞后现象.测试表明,通信延时大大减小,会议中转概率有明显提升.
Most of the traditional SIP systems for group communications are based on client / server model which will cause poor scalability and reliability, voice lag caused by uneven delay. Multi-party communication mechanism based on CMN （Conference Management Node） can solve the above problems. The mechanism will find a CMN for each conference and create an application multicast tree. By using P2P-SIP, the mechanism can support SIP protocol. CMN will be fotmd when a conference is established which enhances scalability and rdiability of the system; dday between CMN and each member is low which impoves quality of voice communication. Delay between Conference Management node and members are balance to prevent voice lag caused by unbalance delay, avoiding unfairness in some special cases. Simulation results show that the conditions of delay and difference of delay are improved greatdy by the mechanism.
出处
《微电子学与计算机》
CSCD
北大核心
2009年第8期9-12,17,共5页
Microelectronics & Computer
基金
国家自然科学基金项目(60703050
60731160630)
关键词
对等计算
组通讯
延时
peer-to-peer computing
group communication
delay
