Table 2 Pseudo code of GG-SVNM algorithm

Input: A physical network G _S  = (N _S , L _S ), a virtual network request G _V  = (N _V , L _V ).

Output: A survivable mapping solution considering the location constraints of virtual nodes.

Step 1: Calculate CMS _i for each physical node.

Step 2: Map the original virtual network.

The location constraints must be satisfied while mapping the virtual nodes.

Step 3: Update the resources of the physical network.

Calculate the remaining capacities of the physical nodes and links after mapping the original virtual network. Compute the total mapping costs of all virtual links and nodes from the original virtual network.

Step 4: Map the backup links and nodes.

4.1) Traverse all physical nodes. Then compute the mapping costs of the backup virtual nodes and relevant backup links.

a) Compute the mapping costs of backup links corresponding to backup nodes.

b) Compute the mapping costs of backup nodes.

c) Calculate the reduced costs brought on by the other virtual nodes in CMS _i .

4.2) Select the physical node with minimum mapping costs. Then map the backup node onto it and map the corresponding backup links.

4.3) Update the resources. Calculate the available resources for the links and nodes on the physical network.

Step 5: Calculate the mapping costs of backup nodes and backup links.