The Tunnel Broker and Dynamic Tunnel Peers are not conforming to the requirement of improving the carrying capacity as high as possible, though they have introduced useful mechanisms such as broker and arbiter. 其中隧道代理和动态对等隧道系统虽然不符合尽量提高物理网络承载能力的要求,却在工程上引入了代理和仲裁的机制;