## 4 Semi-Physical Platform Setup and Evaluation for SDN-Based ISTNs
### Test of Label-Based AOS Frame Switching in the Semi-Physical Platform  
First, a bi-directional label switching path is setup for the label-based AOS frame switching. That is, a bi-directional data path from node vx_simulator_01 to node vx_simulator_03 is built, along which data are sent and received simultaneously via port 3 in node vx_simulator_01 (SCID 1). Before the label switching path is set up, node vx_simulator_01 will compute the explicit constraint routing path under the terminal's QoS requirements, i.e., link duration time, forward and/or backward bandwidth and link latency. Figure 19a-c show the three routers' link-state advertisement of the link-state database in node vx_simulator_01, respectively, which are optimized with metrics of link latency, link duration time, and link bandwidth. In Figure 20a, the function \(cspf\_bi\_direction\_calculation\) computes the explicit bi-directional data routing path under multiple QoS requirements, i.e., source node SCID 1 (i.e., the first parameter) to destination node SCID 3 (i.e., the second parameter), link duration time 500 s (i.e., the third parameter), forward bandwidth 200 Mpbs (i.e., the fourth parameter), backward bandwidth (i.e., the fifth parameter 300 Mbps), forward maximum latency (i.e., the sixth parameter 1000 ms), and backward maximum latency (i.e., the seventh parameter 1000 ms), as summarized in Table 5. In addition, Figure 20b,c show the explicit bi-directional data routing path under multiple QoS requirements, i.e., source node SCID 3 (i.e., the first parameter) to destination node SCID 1 (i.e., the second parameter) and the neighbors' ports status, respectively. Because of the **FULL** status of the neighbor's port, the out-port of forward label switching path and the in-port of the backward label switching path (i.e., in-port and out-port) in node vx_simulator_01 is port 3 connected by FPGA board #1 and FPGA board #2. Figure 18: A data communication network sequence diagram for a management and controlling flooding message, i.e., satellite link plan of connections, from node vx_simulator_01 (SCID 1) to other nodes. Figure 19: The link-state database of the optimized OSPF in node vx_simulator_01 (SCID 1). **(a)** The router link states of node vx_simulator_01 (SCID 1). **(b)** The router link states of node vx_simulator_02 (SCID 2). **(c)** The router link states of node vx_simulator_03 (SCID 3). The second step is label distribution for each node along the label switching path. SNMP is applied as the northbound interface protocol for the communication between the  
Figure 20: The explicit constraint data routing computation under QoS requirements and the circumstances of a bi-directional link between node vx_simulator_01 (ingress LER, SCID 1), node vx_simulator_02 (LSR, SCID 2), and node vx_simulator_03 (egress LER, SCID 3). (a) The status of a neighbor’s port and explicit bi-directional data routing path computation in node vx_simulator_01 (SCID 1). (b) The explicit uni-directional data routing path computation between node vx_simulator_01 (SCID 1) and node vx_simulator_03 (SCID 3). (c) The status of a neighbor’s port in node vx_simulator_02 (SCID 2). network management system as the manager in the management plane and the simulated nodes as the agent (i.e., vx_simulator_01) in the control plane.