II. VPN solutions, the core technology: the second layer tunneling. The current VPN solutions, many have adopted a second layer of tunnel technology. The so-called "tunnel" is such a packaging technology, which uses a network transport protocol, other protocols will produce data packets encapsulated in its own packets, the network transmission. Layer Two Tunneling is the second layer frame is encapsulated in the network layer packet, the formation of IP packets transmitted in the Internet. In the second layer of the tunnel has been around for solutions to the most PPTP protocol and L2F protocols mature.
In many ways, Apples iPhone are the E3 game industry Xia Jisheng will show a dark horse, like sleeping blow Qiaoxing the crowd. More importantly, iPhone games may be the most devastating years of innovation. Yes, it is even more so than the Nintendo wii games. In Nintendos GameCube game failed, and everyone thought it would be battles in this cycle alone, in addition to Star Wars fans are eagerly begged Apple to enter the game, no one seriously predicted the company will enter this field. It is clear now that Apple has a large, leading the way into the industrial transfer of this link. Apple in time for E3, this week released the second generation iPhone, upgrading the iPod touch screen and iPhone 2G firmware, and iTunes-based AppStore. However, although the exhibition does not have a grand appearance, but the whole week in the exhibition and on the Internet a few announcements and unexpected revelation, the iPhones remarks is, of rampant. What lit the fire it?