NODE INSERTION AND REMOVAL IN A LOOP NETWORK

Methods and apparatus for implementing a technique for inserting and removing a node in a network loop. In a preferred implementation, a hub port includes a detect element which monitors data from the node and from an upstream node. The detect element sets a first flag when a primitive is received at the port, and sets a second flag when a primitive which is a frame termination primitive is received at the port. A frame termination generator generates frame termination primitives and a buffer data generator generates buffer data. A switching element has a control input, an output, and a plurality of data inputs. One data input is connected to each of an output of the node, the upstream node, the frame termination generator, and the buffer data generator. A control element is connected to the detect element and the control input of the switching element. The control element selects, according to the first flag and the second flag, one of the data inputs of the switching element to connect to the output of the switching element to be output by the port to a downstream node.