Abstract: A method of managing transfer of packets in a packet digital communications network wherein at least some of the packets comprise a plurality of segments is disclosed. The method comprises providing a buffer (104) for storing segments arriving for transmission on a virtual channel, always admitting (150) a segment of a packet on a virtual channel for storage in the buffer (104) when a previous segment of the packet on said virtual channel has been admitted in the buffer (104), rejecting (149) a segment of a packet on a virtual channel for storage in the buffer when any previous segment of the packet on said virtual channel has been rejected for storage, and applying an admission criterion to each first segment of a packet on a virtual channel.

Abstract: A method of controlling the flow of traffic in synchronous transfer mode (ATM) network (10), which brings into possible existence a class (class II) of ATM cells. The ATM network (10) comprises one or more ATM switches (14) coupled by links (20) providing communication channels between the ATM switches (14). The method subjects the class II cells received at an input port of a particular ATM switch (14) to control, originating within the switching element of that ATM switch. The method allows only up to a fixed number of class II cells from a particular input port to be in the switch awaiting onward transfer. Although the control is on class, it nonetheless tends to produce fairness in service among different connections.

Abstract: An apparatus and method are provided for supporting a plurality of virtual channel (VC) connections within a single virtual path (VP) in a digital communications network operating in the Asynchronous Transfer Mode (ATM). The apparatus (56) is combined with the cross-connected part of a conventional VC switch (54) to form a Data Switch (40). A VP switch (42) switches and terminates incoming bandwidth-resourced VPs on lines (48), some of which are carrying non-bandwidth-resourced VCs and switched onto lines 50 on the output side of VP switch 42. VPs on lines (50) are switched and multiplexed by the Data Switch (40). Buffers (66) store cells and a VP rate server. The buffers (66) are significantly larger than in a conventional VC switch to enable smoothing of data flow peaks associated with data flowing from multiple bandwidth resourced VP tributaries into single resourced VP tributaries. Despite the large buffers in the Data Switch (40) congestion may result when data bursts occur on several converging streams.