Abstract: This invention relates to a process for automatically allocating appropriate communication rates to different data communication lines connected to a common multiplex channel, in terms of the traffic on these lines and the available maximum rate S on this channel, so as to improve the data throughput on the common channel. To this end, Traffic T.sub.i.sup.n is, first, valuated on each line at time t.sub.n, according to formula: T.sub.i.sup.n =.beta.F.sub.i.sup.n +(1-.beta.)T.sub.i.sup.n-1In this formula:T.sub.i.sup.n-1 is the traffic valuation at time t.sub.n-1,.beta. is a coefficient within 0 and 1,F.sub.i.sup.n is given by formula:F.sub.i.sup.n =b.sub.i.sup.n [.alpha.+(1-.alpha.)V.sub.M /V.sub.i ]whereinb.sub.i.sup.n is the number of the bits "0" transferred on to the considered line between times t.sub.n-1 and t.sub.n,.alpha. is a coefficient within 0 and 1,V.sub.M is the highest operating rate on the line, andV.sub.i is the actual rate on the considered line.Once the traffic T.sub.i.sup.