^-^-^-^-^-^-^                             ^-^-^-^-^-^-^
  +-------------+    /             \    +-----------------+    /             \
  | Your server |===< Local network >===| Router/Firewall |===< Big Bad World > 
  +-------------+    \             /    +-----------------+    \             /
                      v-v-v-v-v-v-v                             v-v-v-v-v-v-v