Abstract: Virtual concatenation circuitry is disclosed which provides stall need detection and an associated stall mechanism in a network element of a data communication network. The virtual concatenation circuitry in a preferred embodiment is operative to provide differential delay compensation for one or more member streams of a virtual concatenation stream. The differential delay compensation involves introducing delay into at least one of the member streams. The stall need detection aspect of the invention relates to detecting a condition under which introduction of the delay is required for alignment of member streams, for example, upon addition of a member stream to the virtual concatenation stream. Such a condition may arise, for example, if a transmission delay of an added stream is larger than that of all other member streams of the virtual concatenation stream.

Abstract: Virtual concatenation circuitry is disclosed which provides stall need detection and an associated stall mechanism in a network element of a data communication network. The virtual concatenation circuitry in a preferred embodiment is operative to provide differential delay compensation for one or more member streams of a virtual concatenation stream. The differential delay compensation involves introducing delay into at least one of the member streams. The stall need detection aspect of the invention relates to detecting a condition under which introduction of the delay is required for alignment of member streams, for example, upon addition of a member stream to the virtual concatenation stream. Such a condition may arise, for example, if a transmission delay of an added stream is larger than that of all other member streams of the virtual concatenation stream.