Ethernet packet flow control method and associated application apparatus

An Ethernet switch controller for buffering an Ethernet packet received by a source port and transmitting the packet through a destination port, comprising:

• a buffer control unit for allocating and freeing a buffer space;
• a forwarding unit for looking up the destination number of the packet-transmitting destination port according to the destination address of the Ethernet packet, wherein the forwarding unit responds to the destination port number and a source port number of the source port if the destination port is congested and the Ethernet packet is a unicast packet;
• a queue control unit for establishing a link for the buffered Ethernet packet to the queue that corresponds to the connection port according to the connection port number responded to by the forwarding unit;
• and
• a plurality of port control units coupled to the forwarding unit, the buffer control unit and the queue control unit for receiving the Ethernet packet from a corresponding connection port, storing the Ethernet packet to the assigned buffering space inside the buffer control unit and transmitting the Ethernet packet according to the link corresponding to the queue, wherein the unicast packet is converted to a unicast flow control packet for transmission when the Ethernet packet is a unicast packet and the source port transmits the unicast packet.

An Ethernet switch, comprising:

• a buffer for holding Ethernet packets;
• a physical layer device for providing a plurality of Ethernet ports each having a source port and a destination port;
• and
• a switch controller coupled to the buffer and the physical layer device for switching Ethernet packets and transmitting a unicast flow control packet via the source port when the destination port of the received unicast packet is congested.