In the current Westphalian world system, each nation-state is supposed to be the ultimate authority within its own clearly-defined territory, and all nation-states are officially equal to one another regardless of size. The Westphalian system began to emerge in Europe during the 17th century and only really came to define the world order after World War II with the end of Europe’s colonial empires.
National sovereignty is the modern ideal and is supported by international law, but in practice more powerful states can deeply influence the internal affairs of other states without violating international laws. They can also sometimes violate international laws and escape serious consequences.
In East Asia during the 14th to 17th centuries, the concept of nation-states and national sovereignty did not exist. Instead, look for indications of relative power. In translation, this shows up when a polity titles itself “Great” as in Da Ming (Great Ming) or Dai Viet (Great Viet), suggesting they were in the upper position of a hierarchical relationship with a less powerful neighbor. But just because they titled themselves “Great” does not mean all others agreed.
You can see this conflict play out in diplomatic discussions. Who was Lê Duy Đàm, for example? Was he the emperor of Dai Viet, the king of Annan, or the Pacification Commander of the Pacification Commission of Annan? There was no single answer. His title depended on both the speaker and the audience.