中国斜学巷术大学 信息网偏与协议 VERIITY OF SCIENCE AND TECHNOLOOY O年C框NA Switched Virtual Circuit (SVC) UNI=User-to-NetworkInterface NNI=Network-to-Network Interface Input Output Input Output Port VPIVCI Port VPINCI Port VPIVCI Port VPIVCI 29 3 45 1 64 3 29 1 64 3 29 3 29 64 3 29 1 64 UNI Signaling UNI NNI Signaling 2 3 Signaling B Input Output Input Output Port VPIVCI Port VPIVCI Port VPIVCI Port VPINCI 2 52 1 29 64 3 29 64 329 3 29 1 64 3 29 1 64 Dynamically tear down connections via signaling信息网络与协议 Switched Virtual Circuit (SVC) B D NNI Signaling C UNI Signaling Input Output Port VPI/VCI Port VPI/VCI 1 64 3 29 3 29 1 64 Input Output Port VPI/VCI Port VPI/VCI 2 52 1 29 1 64 3 29 3 29 1 64 Input Output Port VPI/VCI Port VPI/VCI 1 29 3 45 1 64 3 29 3 29 1 64 Input Output Port VPI/VCI Port VPI/VCI 1 64 3 29 3 29 1 64 A UNI Signaling UNI = User-to-Network Interface NNI = Network-to-Network Interface Dynamically tear down connections via signaling 1 2 4 1 3 3 2 4 2 1 3