Via Technologies, Inc.

Jen-Kai Chen

Jiann-Hwa Liou

Yu-Ju Lin

Hsiang-Yi Huang

Wei-Pin Chen

Yun-Fei Chao

Hsiao-Lung Wu

Yeong-Chian Hu

Chien-Shu Tseng

ChaoCheng Cheng

Chao-Cheng Cheng

A network switching apparatus and method for congestion control. Each one of the connection ports of the switching apparatus includes a low priority queue and a high priority queue. When a data packet enters a switching apparatus, the switching apparatus according to the type of the data packet enqueues the data packet to the low priority queue or the high priority queue. When congestion occurs at the switching apparatus, the low priority queue and the high priority queue can respectively perform the different ways of the congestion control, according to the input congestion mode. Also, when the switching apparatus receives a pause frame, response flow control can be performed, according to the output congestion mode. Since the different ways of the congestion control are performed according to the different types of the data packet, the congestion control can be optimized.

Networking switching apparatus and method for congestion control

An Ethernet switch with rate control and associated method is provided. Each port in the switch has individual settings of egress/ingress) rate control, which are stored in a register and configured based on required rates. The switch uses data volume that a port can output/input within each unit time to control egress/ingress rate of the port. Further, the egress rate can be precisely controlled by using uniform random numbers provided by an random number generator of the switch, and the ingress rate can be advantageously controlled by combining a proper kind of congestion control, which is performed according to the capability of a device connected to the port, such as full-duplex or half-duplex, and flow control.

Ethernet switch with rate control and associated method

A method for easing data transmission congestion in a switch device having a plurality of ports. The switch device includes a shared buffer capable of dividing into a plurality of buffering units. The method comprises the steps as follows. A plurality of output queues are provided, in which the output queues have a one-to-one correspondence with the ports, and each output queue has a number of reserved buffering units. The buffering unit(s) are then assigned in the shared buffer. A packet is received from a source port and storing the packet in an assigned buffering unit. The target port of a packet is determined according to a header of the packet. Then, the buffering unit containing the packet is linked to the output queue that corresponds to the target port. The free buffering units are thus controlled according to a number of reserved buffering units in the output queue and a triggering or a terminating condition of the source port.

Method and switch controller for easing flow congestion in network

A method and apparatus for accessing a non-symmetric dual-slot address table having two entriesthat are different in size. When writing data, the data is hashed to generate a hash value. Then, the data is written to a slot corresponding to the hash value in the entryWhen there was data in the slotthe hash value is mapped to a sub-address and a share value, and then a slotcorresponding to the sub-address is selected from the entryAfterwards, the SMAC tag, the share value and the source port are written to the slotIn addition, when transmitting the packet, a hash value is generated according to the DMAC address. Then, a SMAC tag, the share value and the source port are read according to the hash value. After compared, the packet is transmitted.

Method for accessing a non-symmetric dual-slot address table and switching apparatus using same

A switch controller using a congestion control method can relieve congestion in a network. The Ethernet switch controller has the capacity to select a suitable congestion control mode according to each connection port and state of the connected device. If a flow control mode is selected, the switch controller issues a flow control frame and waits for the passing of a guard period roughly equivalent to a period of about inputting three packets. If the connected device continues to transmit network packets after the guard period, the switch controller switches from the flow control mode to a drop control mode. Hence, the received packets are discarded and congestion is prevented. Consequently, the switch controller of this invention can still carry out congestion control operation when the switch controller is connected to a device having no standard flow control capability.

Method and switch controller for relieving flow congestion in network

A output queuing method for forwarding the packets sequentially in a switching network. Each port is related to a port output queue and a global output queue is shared by all port output queues. A FIFO (First In First Out) block is allocated into each port output queue and the global output queue. The FIFO block contains a number of FIFO nodes. Based on the type and destination ports of the received packet, the fields of the related FIFO node in the port output queue and the global output queue are set. The packets are sent out or skipped based on the related fields.

Output queuing method for forwarding packets in sequence

A method for compensating for clock signal difference between a switch and peripheral device, including a receiving process and a transmitting process. For the receiving process, after an N-th packet is received, a first counter is triggered and begins to count. When an (N+1)-th packet is inputted, the counter stops counting and then an inter-packet gap IPG(N, N+1) between the N-th packet and the (N+1)-th packet is recorded into the N+1 queue link node QLN(N+1) according a counting value by the first counter; otherwise, the first counter keeps counting. For the transmitting process, after an inter-packet gap IPG(M&#x2212;1, M) is obtained, and the M-th packet is transmitted, and then the second counter is triggered to begin to count. When a counted value by the second counter is equal to the clock cycle value corresponding to the inter-packet gap IPG(M&#x2212;1, M), the second counter stops counting. When an inter-packet gap IPG(M, M+1) is obtained, and the (M+1)-th packet is then transmitted; otherwise, the second counter keeps counting.

Method for compensating for clock signal difference between a switch and a peripheral device, and associated apparatus

A method for buffer management and a controller of the same are disclosed. In the buffer management method, a first control mode is performed, and a plurality of bits are used to control a bit mask region of a memory. A second control mode is performed, and a plurality of unused addresses in a link region of the memory is cached. A third control mode is performed, to control a plurality of second unused addresses in the link region by a linked list. The controller comprises a plurality of bits for controlling a bit mask region; a plurality of address cache units for caching a plurality of first unused address of a linked list in a link region; and a pointer for always pointing to a head of the linked list in the link region, wherein the linked list links a plurality of second unused addresses.

Buffer management method and a controller thereof

A method and system is provided for use on a switching hub in a packet-switching network for handling the output queuing of received packets in the switching hub to be more efficient and cost-effective. This method and system is characterized in the provision of a broadcast output queue in addition to the output queues at the ports of the switching hub, with the broadcast output queue being exclusively used for sequencing broadcast packets and the output queues being used exclusively for sequencing unicast packets. When a broadcast packet is received, the method and system assigns a free-list link node to the broadcast output queue, but not to the output queues, and meanwhile adds one to the broadcast count in each of the last link node in each of the output queues. When a certain port completes the outputting of all associated unicast packets, it is checked whether the broadcast count in the last link node in each output queue is zero or nonzero; if nonzero, the switching hub then outputs every broadcast packet indicated by the broadcast count. The disclosed method and system not only allows a reduced number of memory accesses as compared to the prior art but also requires a low memory capacity to implement, and therefore is more efficient in operation and more cost-effective to implement than the prior art.

Method and system for handling the output queuing of received packets in a switching hub in a packet-switching network

A method for performing a MAC address lookup in a network switch of an Ethernet network is provided, using a memory structure including a number of multi-slot buckets. Each of the multi-slot buckets is mapped to a hash key derived from a MAC Address. Each of the multi-slot buckets has a number of forwarding table section, each storing a number of the forwarding table entries. If two forwarding table entries are stored in each forwarding table section of a 4-slot bucket &frac14; memory space and &frac12; access time can be saved. Thus, the lookup for the forwarding table according to the MAC address in the Ethernet switch IC can be effectively performed.

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Taipei, Taiwan

Jen-Kai Chen