虚拟专用网中语音电话的应用及网络性能

Application of voice-over-IP in virtual private network and network performance

为研究虚拟专用网(VPN)基于Internet协议安全性(IPSec)进行语音电话(Vo IP)数据的输送及网络性能的影响,在分析IPSec技术、隧道封装技术和VPN技术原理的基础上,设计了一个企业的VPN网络拓扑,对语音路由器、语音交换机和外网服务器的配置及其作用进行了说明,利用OPNET平台对网络性能进行了仿真和分析.结果表明,VPN的隧道封装技术以及数据机密性、数据完整性、起源认证等加密措施使得网络配置变得复杂,语音数据在VPN隧道的传输过程中,丢包率不高,但传输速率变得缓慢,网络延迟加大,IPSec采用的安全策略导致网络抖动明显,收敛速度慢,语音质量也随之减低.

To study the voice-over- internet protocol （VoIP） data transmission through virtual private network （VPN） based on internet protocol security （IPSec） and the influence on network performance, an enterprise＇s VPN network topology was designed based on the analysis of IPSec technology , tunnel encapsulation technology and VPN technology. The configuration and the function were explained on the voice router and the voice switch and the outgoing server, the network performance was simulated and analyzed based on OPNET performance. The results show that VPN can further complicate the configuration because of its tunnel encapsulation technology and encryption measures, such as data confidentiality, data integrity and authentication, etc. ;in the process of the VPN tunnel transmission, VoIP voice data has low packet lost rate, but the transfer rate becomes slow and the network delay increases;the obvious network jitter, slow convergence speed, low VoIP quality are caused by IPSec security policy.