⑴ each time the user access to a new target site, will need to exchange security information between the source site and the new target site, the whole implementation process is relatively complex. In addition, when a moment many users need simultaneous access to multiple services, the network data

(1) each time they visit a new destination site, you will need to source site with the new destination exchange between sites, and the entire safety information for more complex process. In addition, when a moment, it is a lot of users need to access multiple services, the data in the network traffi