**Appendix A**

Based on Proactive Approach (PA) or Hybrid Approach (HA), the details of pseudo code of T, ECMP-T or Fermat-point model can be presented respectively in Algorithm A1 or Algorithm A2.


**Input:** *P*; *S*; *D*; *L* **Output:** *I* 1: **if** *P* = ∅ **then** 2: *I* = ∅ 3: **for** node *i* in *P* **do** : ... ... 4: **return** *I*


**Input:** *NSDN*; *P*; *S*; *D*; *L* **Output:** *I* 1: *I* = ∅ :... ... 2: *SP* ← *Select(NS,D, P)* or *Select(NS,D,L, P*) 3: **if** the SDN node-set *SP* =∅ **then** 4: **for** node *i* in *SP* **do** : ... ... 5: **else** 6: *Algo3(NSDN,S,D,L)* or *Algo4(NSDN,S,D,L)* 7: **end if** 8: **return** *I*
