Virtual private networks over Internet

As we all know, VPNs based on the Internet are the mostpopular and prominent. The advantages of VPN over theInternet are obvious; it is cost-effective and flexible.However, there are problems with VPN oven the Internet.Quality of service is difficult to guarantee when traffic isencrypted because the bits marking QoS cannot be read bythe routers. Tunnelling protocol cannot guarantee aminimum delay due to the IP's best effort routing protocol.Thus, in the Internet VPN, QoS by application is not anoption offered by any service provider, and E-mail has thesame priority as any resource management application.Hence, current VPNs over the Internet cannot supportmultimedia applications, such as high definition TV(HDTV). These types of multimedia application have highsensitivity to delay and jitter, which have a critical impacton the performance of multimedia. The traffic on VPNbased on the Internet passes through several Internetrouters and may experience multiple buffering and multiplexing. Thus jitter is very hard to predict. Online VPN based on optical networks can alleviate this problem. Ourproposal is targeted to provide a service for multiple typesof traffic streams, especially those with very stringent delayjitter requirements and with bursty characteristic, e.g.multimedia applications.

Virtual private networks over Internet

As we all know, VPNs based on the Internet are the mostpopular and prominent. The advantages of VPN over theInternet are obvious; it is cost-effective and flexible.However, there are problems with VPN oven the Internet.Quality of service is difficult to guarantee when traffic isencrypted because the bits marking QoS cannot be read bythe routers. Tunnelling protocol cannot guarantee aminimum delay due to the IP's best effort routing protocol.Thus, in the Internet VPN, QoS by application is not anoption offered by any service provider, and E-mail has thesame priority as any resource management application.Hence, current VPNs over the Internet cannot supportmultimedia applications, such as high definition TV(HDTV). These types of multimedia application have highsensitivity to delay and jitter, which have a critical impacton the performance of multimedia. The traffic on VPNbased on the Internet passes through several Internetrouters and may experience multiple buffering and multiplexing. Thus jitter is very hard to predict. Online VPN based on optical networks can alleviate this problem. Ourproposal is targeted to provide a service for multiple typesof traffic streams, especially those with very stringent delayjitter requirements and with bursty characteristic, e.g.multimedia applications.