In a process of producing polyethylene terephthalate by esterification of terephthalic acid with ethylene glycol and polycondensation, the vapors formed are rectified, the liquid phase is recirculated to the process, and the lower-boiling components are condensed. This process includes the thermal annealing of a structure that incorporates the layers, with the annealing bringing the temperature from a starting temperature to a final annealing temperature while evolving according to a first phase up to a transition temperature, then according to a second phase during which the rise in temperature per unit of time is greater than that of the first phase. The request node includes a copy of the local sequence number in each packet transmitted and increments its local copy of the sequence number only for packets that must be received in order. Furthermore, the tactile feel of the flexible EL dome sheet keypad is improved.