Why 53 bytes for the ATM cell?

Today I will post an interesting and somewhat shocking reason why the cell size of the ATM network was fixed at 53 bytes. The choice of 48 bytes was a political matter. When the ATM standard was being ratified, parties from the United States wanted a 64-byte payload because this was felt to be a good compromise between larger payloads optimized for data transmission and shorter payloads optimized for real-time applications like voice; parties from Europe wanted 32-byte payloads because the small size simplify voice applications with respect to echo cancellation. Most of the European parties eventually came around to the arguments made by the Americans, but France and a few others held out for a shorter cell length. With 32 bytes, France would have been able to implement an ATM-based voice network with calls from one end of France to the other requiring no echo cancellations. 48 bytes ((64+32)/2) was chosen as a compromise between the two sides. 5 bytes of header was also provisioned assuming that the 10% of the total payload was the fair price to pay for the routing info. hence 48+5 = 53 bytes size was standardized for the ATM cell.