Wipe pot clean, bring 4 quarts water to boil.
Add bones and brisket, onion, ginger, spices
Add onion, ginger, Spices, sugar and salt - water should just barely cover everything.
Cover with lid, simmer 3 hours up to 8 hours
Remove brisket (should be fall-apart tender), cool then refrigerate for later.
Simmer remaining soup uncovered for 40 minutes
Strain broth into another pot, discard bones and spices. Should be about 10 cups.
Add fish sauce, adjust salt and sugar if needed. Broth should be beefy, fragrant with spices, savory and barely sweet.