基于ALG的VoIP中NAT穿越技术的研究与实现  

Research and Realization of NAT Traversal Solutions in VoIP System Based on ALG

作　　者：赵慧[1] 楼新远[1] 杨庆伟[2] 

机构地区：[1]西南交通大学信息科学与技术学院,四川成都610031 [2]电子科技大学计算机科学与工程学院,四川成都611731

出　　处：《计算机与现代化》2011年第3期95-97,共3页Computer and Modernization

摘　　要：在VoIP(Voice over Internet Protocol)通信中H.323协议消息携带的地址信息在穿越NAT(Network Address Translation)时,传统的ALG(Apply Layer Gateway)方案采用的全部解码方法,性能较低。为了解决此问题,本文分析ALG技术,采用按需解码的方法,只解码消息的地址信息部分,不需全部重新编码,并做对比实验。结果表明,按需解码所需时间约是全部解码方案所需时间的1/75～1/80,优化了ALG的处理性能。During the VoIP communication,the address information carried by H.323 protocol traveling the NAT,decoding-all method with lower performance is used in the traditional performance of ALG solution.To optimize performance,the paper analyzes the ALG technology and gives a decoding method using on-demand which only decodes the address information of the message instead of re-encoding all.A comparison experiment is carried out which shows that the time of decoding on-demand is about 1/75～1/80 of the decoding-all solution.The problem of low efficiency of ALG treatment is optimized.

关 键 词：ALG 按需解码 NAT穿越 H.323 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]