D. W. Davies; An Historical Study of the Beginnings of Packet Switching, The Computer Journal, Volume 44, Issue 3, 1 January 2001, Pages 152–162, https://doi.or

Any communication network has a finite traffic capacity and if it is offered traffic beyond the limit it must reject some of it. The data-communication network studied here is one employing packet switching, like the Advanced Research Project Agency (ARPA) network. It handles blocks of data, called packets, and longer messages are subdivided, rather in the same way that store in a computer is allocated in pages. A method of controlling congestion is proposed in which there is a finite number of packet carriers in the whole network. When a packet of data is delivered to its destination node the "empty" packet is available for reuse. The empties move randomly round the network and new data must capture an empty packet carrier before being launched into the network. Various elaborations are described that avoid delay in normal conditions. This so-called "isarithmic" method of congestion control supplements and does not replace end-to-end flow control.

A new technique for forcing convergence of the Newton process is described. The technique, which is based upon modification of the pivots during solution of the linearised equations, is compared with a more complicated eigenanalysis approach. The techniques considered are, in general, suitable only for the optimisation of functions for which explicit expressions are available for both first and second partial derivates.

Those computer applications which involve rapid response to events at distant points create special problems in digital communication. Such applications are increasing in number, and could increase more rapidly if better solutions existed to the communication problems.

A switching function is a function of variables which take only the values 0 and 1, and which takes only these values itself. There are 256 different switching functions of three variables, but only 218 of these really depend on all three variables. A switching function of three variables can be expressed in terms of switching functions of two variables. For example F1{F2[A, F3(B, C)], F4(B, C)} can be shown to represent any function of A, B, and C if F1 F2 F3 and F4 are suitably chosen switching functions. The problem solved is: for each switching function of three variables, what is the least number of switching functions of two variables required express it?