Distributed Double Loop Computer Network (DDLNC) is an access method based on a further development of the Distributed Loop Computer Network
(DLCN). It is based on the register insertion procedure.In the DDLNC procedure, two rings with opposite transmission directions and buffers in the ring ensure that the shortest path between two communicating stations is used in each case. Moreover, in case of partial system failures, communication
can still be maintained by cleverly utilizing the remaining resources.
Each DDLCN ring interface has four connections to the rings: two inputs and two outputs each. Messages not destined for the current station are passed onto the ring in the manner discussed for DLCN after buffering. If a station itself has to send a packet, it has to decide on which ring, i.e. ultimately in which direction, this has to be done. It is useful to make this decision depending on the distance of the communication parameter, related to the direction and under observation of the total traffic on the corresponding ring.