Abstract:
A network switch having switch ports for full-duplex communication of data packets with respective network nodes according to Ethernet (IEEE 802.3) protocol that allocates a prescribed number of external memory bandwidth slots between high data rate ports based on the compared amount of network traffic on the respective ports. A scheduler within an external memory interface initially assigns memory access slots to the respective high data rate ports according to a prescribed sequence. If the scheduler subsequently detects that the network data traffic on a port having less slots is higher than the traffic on a port having more slots, the slots are swapped between the high data rate ports. Additionally, a clock multiplexer in one of the high data rate ports adjusts the data rate of the port dependent upon the number of slots assigned to that port. The swapping of bandwidth slots between the high data rate ports along with the adjustment of the port clock rate enables the efficient use of limited memory bandwidth resources.
Abstract:
A novel method of data forwarding is provided in a network switch having multiple ports including at least one backbone port for data communications with backbone network nodes. Destination information of a received data packet is compared with a predetermined set of address data in an address table. If the packet's destination information is not found in the address table, the received data packet is forwarded to the backbone port. Further, the source address information of the received data packet may be compared with the address table. In a regular mode of operation, if the packet's source address information is not found in the address table, this information is added to the address table. However, in a backbone mode of operation, the address information of a data packet received from the backbone port is prevented from being added to the address table. The switch may have backbone ports provided for multiple VLANs supported by the switch. A first data packet received from a first VLAN is forwarded to at least one backbone port for that VLAN, if the packet's destination information is not found in the address table. Similarly, a second data packet received from a second VLAN is forwarded to at least one backbone port for the second VLAN if the packet's destination information is not found in the address table. A backbone vector storage is provided for identifying backbone ports for the multiple VLANs supported by the switch.
Abstract:
An apparatus and method are disclosed for regulating the flow of data between plural network stations through a network switch. A receive port functions to receive data frames from a first network station, and a transmit port outputs the received data frames to a second network station. A programmable threshold register is provided for storing a threshold value that indicates a saturation level for the internal resources of the transmit port. Control circuitry is used to monitor the internal resources of the transmit port and determine whether or not the threshold value has been reached. If the threshold value has been reached, then the control circuitry will implement a flow control process that causes the first network station to discontinue transmission of data frames to the transmit port until the internal resources of the transmit port fall below the threshold value.
Abstract:
A novel system and method of monitoring network activity in a network switching system having multiple ports for receiving and transmitting data packets, and a decision making engine for controlling data forwarding between the ports. Data blocks representing received data packets are placed in data queues corresponding to the receive ports. The data queues are transferred to logic circuitry for processing in accordance with a predetermined algorithm to determine destination information. At least one port for transmitting data packets is identified based on the destination information. In addition, a sniffer port selected among the plurality of ports is identified as a transmit port to provide output of data packets received or transmitted by multiple sniffed ports. A traffic capture mechanism that enables the sniffer port to output data transferred via multiple sniffed ports includes a sniffer port configuration circuit for selecting the sniffer port, and a sniffed port configuration circuit for selecting the multiple sniffed ports. The sniffer port configuration circuit may provide a signal to enable or disable monitoring of data traffic on the multiple sniffed ports.
Abstract:
A network switch configured for switching data packets across multiple ports and for supporting trunked data paths uses an address table to generate frame forwarding information. When a link in a trunked data path experiences a change in its operating status, the trunk data path is reconfigured to reflect the current operating conditions, without reprogramming the address table or powering down the switch.
Abstract:
A novel method of enabling a port of a network switch to support connections with multiple VLANs. The method comprises storing VLAN data indicating a plurality of VLAN identifiers corresponding to the multiple VLANs supported by the port. A VLAN identifier of a data packet received via the port is compared with the plurality of VLAN identifiers determined using the stored VLAN data. The data packet is forwarded for further processing if the VLAN identifier matches one of the plurality of VLAN identifiers. However, the data packet is discarded if the VLAN identifier does not match one of the plurality of VLAN identifiers. Moreover, VLAN information corresponding to a VLAN identifier of a data packet to be transmitted from the port is compared with the stored VLAN data to determine whether the VLAN identifier matches one of the plurality of VLAN identifiers supported by the port. The data packet is prevented from being transmitted from the port if the VLAN identifier does not match one of the plurality of VLAN identifiers.
Abstract:
A network switch having switch ports for full-duplex communication of data packets with respective network nodes according to Ethernet (IEEE 802.3) protocol dynamically allocates external memory bandwidth slots between high data rate ports. An external memory interface determines if a high data rate port makes a request for a bandwidth slot and grants the request if made. The slot is taken from a selected group which is a subset of the total number of slots. If a request for the slot is not made, the external memory interface assigns the slot to another high data rate port. Lower data rate ports in the network switch are assigned fixed slots from those slots not from within the selected group of slots. The dynamic allocation of bandwidth slots between the high data rate port enables the efficient use of limited memory bandwidth resources.
Abstract:
A network switch having switch ports for full-duplex communication of data packets with respective network nodes according to Ethernet (IEEE 802.3) protocol that flexibly assigns memory access slots to access an external memory according to programmable information. A scheduler within an external memory interface assigns the memory access slots to the respective network switch ports according to a programmed sequence written into an assignment table memory from an external programmable data storage device.
Abstract:
A novel system and method of automatically detecting a change in network node connection in a multiport data switching system having receive ports for receiving data packets from network nodes, and a decision making engine for controlling data forwarding. Data blocks representing received data packets are placed in data queues corresponding to the receive ports. The data queues are transferred to logic circuitry for processing in accordance with a predetermined algorithm. This processing includes automatically detecting a change in connection between at least one of the network nodes and at least one of the receive ports, based on a search of an address table having address information relating to the receive ports. The address table may be searched for an address entry having a source address and VLAN address information that match a source address and VLAN address information of the received data packet. Receive port data written in the address entry having matching address information are checked to determine whether these data identify a receive port arranged in the same trunk as the receive port, from which the data packet is transferred. The address entry is automatically updated with new information, if the receive port identified in the address entry and the actual receive port are in different trunks.
Abstract:
Techniques for efficient database formation and search in applications embedded in a media device are provided. The search may be performed synchronously with presentation of media programming content on a nearby media presentation device. A mobile media device captures some temporal fragments of the presented audio/video content on its microphone and camera, and then generates query fingerprints for the captured fragment. A local reference database resides on the mobile media device and a master reference database resides on a remote server with a most recent chunk of reference fingerprints transferred dynamically to the local mobile media device. A chunk of the query fingerprints generated locally on the mobile media device are searched on the local reference database for continuous content search and identification. The method presented automatically switches between the local search on the mobile media device and a remote search on an external search server.