Abstract: An arrangement and a method of maintaining a count of the number of copies of a frame that have been transmitted from a network switch uses a cache memory to store the number of copies of a frame to be transmitted from the network switch. A queue is used to queue entries that indicate the transmission of a copy of a frame, and these queued entries are released to a buffer manager. Whenever a transmission is made of a copy of this frame, and the buffer manager examines the entry indicating this transmission after the entry leaves the queue, the buffer manager searches for a corresponding entry in the cache memory and changes the copy number (i.e., the count of the number of transmissions) of that frame in the cache memory.

Abstract: A scalable multiport switch that receives and transmits data through a plurality of ports is provided with a plurality of internal buses, an external memory interface, and a slot manager. The external memory interface is coupled to the internal buses and has an external memory port for coupling the external memory interface to an external memory. The slot manager schedules access to the external memory through the internal buses and the external memory interface in a series of time slots. Each slot consists of m clock cycles to transfer n bytes of data. The slot manager is operable at a selectable one of multiple frequencies, the operating frequency of the slot manager being selected to match an operating frequency of the external memory. The slot manager increases the number of slots per given period of time with increasing operating frequency of the slot manager, but maintains the number of clock cycles per slot constant, thereby providing greater access to other sources of data.

Abstract: An integrated multiport switch (IMS) in which an on-chip management information base (MIB) accumulation processor enables monitoring of a significantly larger number of MIB objects to be stored in external memory while minimizing, media access controller (MAC) complexity. A MAC for each port in the IMS outputs a MIB report for each transmission or reception of data according to a specific compressed format to a MIB engine that can be centrally located on the chip. The compression of the data that represents the monitored events enables conservation of the capacity of MAC buffer elements. The MIB report is immediately dispatched to the MIB engine upon receipt or transmission of a data frame. The MIB engine decodes the MIB report into a plurality of associated MIB objects. which are temporarily accumulated until the external memory is updated.

Abstract: An integrated multiport switch (IMS) in which an on-chip management information base (MIB) accumulation processor enables monitoring of a significantly larger number of MIB objects to be stored in external memory while minimizing media access controller (MAC) complexity. A MAC for each port in the IMS outputs a MIB report for each transmission or reception of data according to a specific compressed format to a MIB engine that can be centrally located on the chip. The MIB engine decodes the MIB report into a plurality of associated MIB objects, which are temporarily accumulated until the external memory is updated. The MIB engine initiates the stored MIB value updating process by retrieving the values from the external memory and adding the accumulated MIB objects to the retrieved values. The updated MIB objects are then transmitted back to the external memory for storage therein and the MIB engine object values are cleared.

Abstract: An apparatus and method of controlling the transmission of copies of a frame of data from a multiport device, such as a multiport network switch, determines which ones of the ports are designated to transmit a copy of a multicopy frame received at the switch. The switch then determines which of these designated ports are not available to transmit a copy of the frame. The copies are transmitted from those designated ports that are available to transmit a copy of the multicopy frame, while the copies are discarded for those designated ports that are not available to transmit a copy of that multicopy frame.