包地址重写 Server 1 (address 1) Address dispatcher User Client (IP-SvA) 5 之 3 step 1: Document request (IP-SvA) Server N (address N) Step 2: Web-server selection step 3: Packet rewriting (IP-SvA-> address 1) step 4: Packet routing step 5: Server sends each packet to the dispatcher step 6: Packet rewriting (address 1 ->IP-SvA) step 7: Document response (IP-SvA)包地址重写