A dynamic switch and its protocol for establishing dynamic connections in a link by the use of frames, each frame having an identification of the source of the frame, an identification of the destination of the frame for the requested connection, and link controls to maintain, initiate or terminate a connection between the source and the destination. The frames are bounded by a start of frame delimiter and an end of frame delimiter which may also act as a connect link control and a disconnect link control, respectively, and the onnections are made through the dynamic switch having dynamic-switch ports. The state of a dynamic-switch port is changed dependent on its present state, the dynamic connection requested, and the direction and type of frames passing through the dynamic-switch port.