Abstract: In a forwarding network comprising a function chain network controller, a plurality of intermediate network functions (NFs) and flow-based chain selectors (FBCSs) forming VNFs and configured to transfer data packets via a plurality of links, a method comprising a FBCS requesting substitution in the header representation of function chain entries of a data packet header in a flow with a different representation of function chain entries, wherein the flow bypasses at least one intermediate FBCS based on the substituted function chain entries representation. The function chain network controller discovers FBCS capable nodes and their topology, and maintains a function chain substitution state and distributes it to the FBCS relevant substitutions. The function chain network controller distributes a list of adjacent FBCSs to the FBCS, and distributes a list of abstracted adjacent FBCSs to the FBCS and translates requests from an abstracted value to a real value.

Abstract: In a forwarding network comprising a function chain network controller, a plurality of intermediate network functions (NFs) and flow-based chain selectors (FBCSs) forming VNFs and configured to transfer data packets via a plurality of links, a method comprising a FBCS requesting substitution in the header representation of function chain entries of a data packet header in a flow with a different representation of function chain entries, wherein the flow bypasses at least one intermediate FBCS based on the substituted function chain entries representation. The function chain network controller discovers FBCS capable nodes and their topology, and maintains a function chain substitution state and distributes it to the FBCS relevant substitutions. The function chain network controller distributes a list of adjacent FBCSs to the FBCS, and distributes a list of abstracted adjacent FBCSs to the FBCS and translates requests from an abstracted value to a real value.

Abstract: A clock reconstruction mechanism for synchronous TDM communications traffic transported over asynchronous networks such as Ethernet networks. The invention is applicable to edge switches in Metropolitan Area Networks (MANs) that transport legacy TDM traffic using a Circuit Emulation Services (CES) module whereby TDM traffic is encapsulated and transported across the Ethernet network where it is de-encapsulated and clocked out to the destination. The mechanism encapsulates the input TDM data stream into Ethernet packets and inserts a network timestamp within the packet. At the destination CES, a local timestamp is generated for each received packet as it is received. The network timestamp is extracted and input along with the local timestamp to a Digital Time Locked Loop (DTLL) which is operative to accurately reconstruct the original transmit TDM clock.

Abstract: A forwarding table comprising a combination of a hash table and a content addressable memory (CAM). The forwarding table combines a one way hash table and a small CAM to perform the forwarding information retrieval function. The CAM is used when an address cannot be found in the hash table. When MAC addresses are being added to the forwarding table, they are first tried in the hash table. The address is applied to the hash function and a resulting index input to the hash table. If a hit occurs, it indicates that an entry at that index already exists and a location in the CAM is then allocated for that address. As long as the CAM does not become full, a 100% hit rate is guaranteed. During retrieval, the hash table or the CAM forms the forwarding information output to the next processing stage. If an entry is not found in the hash table, it will typically be found in the CAM. If no entry is found in either, the received frame is flooded to all the ports of the network device.

Abstract: A dynamic queuing system wherein a single memory is shared among a plurality of different queues. A single memory, termed a queue memory, is by ally shared by one or more queue. The queue memory is divided into a plurality of memory blocks that we initially empty. An empty list functions to track which memory blocks are empty and available for use in a queue. Each queue constructed utilizes one or more memory blocks. When a queue becomes full, an additional memory block is allocated to it. Conversely, as memory blocks of a queue are read, i.e. emptied, they are returned to the pool of empty memory blocks for use by other queued.

Abstract: An apparatus and associated method for performing flow switching (tag switching) in a frame switching environment. The flow switching apparatus provides a mechanism whereby flows are identified and tags assigned to them. The identification and assignment of tags to flows is made Independently of other network entities and does not require communications with any other entities within the box itself or other entities in the network. The forwarding decisions are calculated once and stored in a cache or a look up table which can be accessed very quickly. The tag is used as an index into the cache or LUT such that if an entry is found in the cache or LUT for that particular tag, the forwarding decision does not have to be made again. This serves to greatly reduce the time to obtain a forwarding decision which is used by the switching fabric in steering the input frame to the appropriate output port(s). Multiple queues are used along with the cache to facilitate the forwarding of the frames.

Abstract: A queue having a ‘duplicate’ counter associated with each entry whereby duplicate data is not stored in the queue. Before data is placed in the queue, the queue is searched for an entry matching the data to be written. If a match is found, the duplicate counter associated with the entry is incremented. Further, if a match is found and the data stored therein is inconsistent with the current data, the contents of the queue are updated and the duplicate counter associated with the entry is reset to one. If a match is not found, the data is written to the queue and the duplicate counter associated with the entry is initialized to one.

Abstract: An apparatus for and a method of compressing the forwarding decision for a frame within a network device. A forwarding decision is compressed yielding a forwarding pointer that occupies far less memory space than the corresponding output port vector. The compressed forwarding pointers are stored in a forwarding table that is accessed using a hash function. A forwarding CAM is used to resolve conflicts in the hash table. The output port vectors are stored in an output port vector table that comprises a relatively small number of possible combinations of the port vector. A forwarding decision is made for each received frame by a forwarding processor in the device. The forwarding decision is represented by a compressed forwarding pointer that is stored in a table and associated with the received frame. At some later point in time, the frame is output to one or more destination ports in accordance with a corresponding output port vector.

Abstract: An enhanced cells-in-frames (CIF) network system for connecting a local-area-network (LAN) to an ATM network consists of CIF end-stations and an enhanced CIF attachment-device attached to a LAN segment. The enhanced CIF attachment-device in addition to performing its conventional functions, recognizes connection requests between local CIF end-stations and sets up short-cut forwarding between such end stations allowing them to transfer CIF frames directly over the Ethernet. In a conventional system such local traffic would broken up into a plurality of cells and sent over an ATM network.

Abstract: A traffic management unit for implementing Traffic Management (TM) of Available Bit Rate (ABR) traffic on an Asynchronous Transfer Mode (ATM) network is described. The traffic management unit comprises a traffic management processor coupled to a traffic management memory. The traffic management processor is coupled between a data processor and an ATM interface. An Ethernet workstation is coupled to the data processor through an Ethernet interface. An ATM switch is coupled to the traffic management processor through the ATM interface. The traffic management unit is implemented as a unit separate from the cell scheduling data processor. In addition, in order to utilize network congestion information more efficiently, VCs are grouped according to their output destinations or their path through the network. Congestion feedback for one VC is applied to other VCs within the group.