The Iroquois Constitution or the Great Law of Peace is a great oral narrative, it documents the formation of a League of nations which include the Cayuga, Onondaga, Mohawk, Oneida and Seneca, later on in 1722 a six nation was included, the Tuscarora. It was made to stop the fighting between them.
The smoke symbolizes the idea that the Five Nations are united under the Great Peace.
"The Smoke of the Confederate Council Fire shall ever ascend and pierce the sky so that other nations who may be allies may see the Council Fire of the Great Peace."
We can see that the smoke is used a signal, the indians used it to communicate through the distance as it "pierces the sky" or is seen from far away. In this case it sends the message to the allies that the Council still exists and therefore the nations shall be united, stopping aggressions between them.
