Control method and system for packet transmission

A control system for packet transmission, comprising:

• a first port;
• a second port providing a second packet count;
• a third port providing a third packet count;
• a storage medium, comprising a first queue applied to the first port, a second queue applied to the second port, and a third queue applied to the third port;
• a dequeue control unit, coupled to the storage medium;
• a forward control unit, capable of receiving a packet providing a port count through the first port, queuing the packet in the first queue, implementing a lookup operation according to a lookup table to locate desired destination ports, and transmitting the packet when the destination port determination is complete;
• a queue control unit, coupled to the forward control unit, the storage medium, and the dequeue control unit, capable of receiving and queuing the packet from the first queue to the second queue, transmitting first queuing information to the storage medium, determining whether the port count is greater than a predetermined value, if not, outputting the packet through the second port, and, if so, sending a first message;
• a multicast forward control unit, coupled to the forward control unit, the queue control unit, and the dequeue control unit, capable of receiving the first message from the queue control unit, adding one to the second packet count, determining whether the second packet count is greater than a threshold value, and, if so, sending a stop forward message to the forward control unit but not sending a grant message;
• wherein, the forward control unit receives the stop forward message, does not queue subsequent packets from the first queue to the second queue but to the third queue directly, and requeues packets to the second queue when queued packets in the second queue are completely output.

A control method for packet transmission, comprising:

• defining a second packet count applied to a second port, a third packet count applied to a third port, and a port count;
• receiving a packet through a first port and implementing a lookup operation to locate desired destination ports;
• adding one to the second packet count when the port count is greater than a first predetermined value;
• determining whether the second packet count is greater than a threshold value;
• and
• if so, not transmitting subsequent packets to the second port but to the third port directly.