| (1) Create a number of virtual network request events |
| (2) The physical link resources are divided into the primary and backup flow resources, and set the ratio as 1 : 1. |
| (3) WHILE (Virtual network events are not fully processed) |
| (4) IF (The event type is a new virtual network request) |
| (5) Calculate the GRC value of the physical node according to formula (1) |
| (6) FOR (The number of virtual nodes) |
| (7) FOR (The number of virtual links connected to the node) |
| (8) The two nodes on the same virtual link are mapped in two different domain sub-networks. |
| (9) IF (Cannot find a different sub-network) |
| (10) Randomly select a domain network as a mapping network and put the candidate physical node |
| number found in the candidate []. |
| (11) ELSE |
| (12) Find the candidate physical node within the selected sub-network and place the serial number in |
| the candidate []. |
| (13) ENFIF |
| (14) ENDFOR |
| (15) IF (!candidate []) |
| (16) Return Node mapping failed. |
| (17) ELSE |
| (18) Select the eligible physical node in the candidate [] as the mapping node according to the value of |
| GRC from large to small; |
| (19) ENDIF |
| (20) ENDFOR |
| (21) Form a virtual request node mapping scheme; |
| (22) ENDFOR |
| (23) FOR (The number of virtual links) |
| (24) Use the Dijkstra method to find the primary flow path and the backup flow path between Node_From |
| and Node_To; |
| (25) IF (!Primary flow path !Backup flow path) |
| (26) WHILE (Candidate [].size > 0) |
| (27) Randomly re-select the physical node in Candidate [] as the mapping node for the virtual node; |
| (28) Delete the mapping node number in Candidate []; |
| (29) Use the Dijkstra method to find the primary flow path and the backup flow path for the new |
| node scheme; |
| (30) IF (Candidate [].size ==−1) |
| (31) Return Link mapping failed; |
| (32) ENDWHILE |
| (33) ENIF |
| (34) ENDFOR |
| (35) Form a new link mapping scheme; |
| (36) ENIF |
| (37) ELSE (The event type is the virtual network request to leave) |
| (38) Update the virtual network request information; |
| (39) Update physical network resources (including node resources, primary flow resources, and backup link |
| flow resources); |
| (40) ENDWHILE |
