This is coolbert: Dien Bien Phu, Part III:

After being caught off guard by the French decision to create a bastion in an area that they controlled, General Giap, the Viet Minh commander, decided after accessing the situation, to indeed respond to the French challenge. Giap decided also that this was to become the decisive battle of the first Indo-China war. A knock out blow from which the French would not recover. Victory would be to the Viet Minh! Giap mobilized his forces for the offensive that was to succeed. Four divisions of his best troops were brought to the area of DBP. This was an infantry force of about 40-50,000 troops. To support the assault force, a coolie/porter force of almost the same number [40-50,000] was created. This coolie/porter force was to keep the Viet Minh attackers supplied throughout the whole battle. What Giap was able to assemble in the form of fire support was most formidable. This was the key to the subsequent success of the Viet Minh. Giap was able to assemble about 144 pieces of tube artillery to employ against the French. The Viet Minh also possessed a substantial number of mortars, rocket launchers, and recoilless rifles that could also be brought to bear against the French defenders. In addition the Viet Minh had a substantial number of 37 mm AAA guns at DBP. These guns also were to prove vital to Viet Minh success. Organized into probably two battalions of 18 guns each. The substantial firepower amassed by the Viet Minh at DBP was unanticipated by the French, much to their subsequent woe.

[144 pieces of tube artillery was probably organized into two battalions per division, 36 tubes per division, 18 per battalion, one battalion each of 75 mm and one battalion each of 105 mm].

[Chairman Mao gleefully insulted the French Ambassador to China at a banquet by saying that the gunners of the artillery at DBP were Chinese. This may have been for the 105 mm artillery pieces, probably U.S. howitzers captured from the Nationalists].

[In contrast, the French at DBP possessed 24 pieces of tube artillery].

coolbert.