Packet forwarding apparatus using token bucket algorithm and leaky bucket algorithm

Abstract

A packet forwarding apparatus and network system for providing different types of bandwidth control services to the user; in which a packet forwarding apparatus for transferring data comprises an interface unit for sending and receiving packets, and a traffic shaper for controlling the packet transmission timing and a packet switch for sending an output to the interface unit as the destination of the received packet; and the traffic shaper uses a token bucket algorithm when transmitting a packet to guarantee the minimum frame rate, and uses a leaky bucket algorithm when limiting the peak frame rate.

1 . A. packet forwarding apparatus for transmitting data comprising:
 an interface unit for sending and receiving a fixed length frame including a variable length packet;   a packet switch for outputting the received variable length packet to the interface unit as a destination of the received variable length packet; and   a traffic shaper for controlling packet transmission timing of the received variable length packets,   wherein the traffic shaper comprises a bandwidth control unit for controlling a to-be-transmitted bandwidth of the received variable length packet, and a packet buffer for temporarily storing the received variable length packet, and   the traffic shaper stores a portion of the received variable length packet in another fixed length frame in a case where the received variable length packet as read from the packet buffer cannot be stored in the fixed length frame to be transmitted out of the packet forwarding apparatus.   
     
     
         2 . The packet forwarding apparatus according to  claim 1 , wherein the traffic shaper comprises a fragment buffer for temporarily storing the received variable length packet as read from the packet buffer, and
 the traffic shaper temporarily stores at least a portion of the received variable length packet in the fragment buffer in a case where the received variable length packet read from the packet buffer cannot be stored in the fixed length frame to be transmitted out of the packet forwarding apparatus.   
     
     
         3 . The packet forwarding apparatus according to  claim 1 , wherein the traffic shaper comprises a read data length control unit for counting a quantity of data read from the packet buffer, and
 the read data length control unit determines whether or not the received variable length packet read as from the packet buffer can be stored in the fixed length frame to be transmitted out of the packet forwarding apparatus based on a counting result of the quantity of the data read from the packet buffer.   
     
     
         4 . The packet forwarding apparatus according to  claim 3 , wherein the read data length controller outputs a fragment signal to the fragment buffer in a case where the read data length controller determines that the received variable length packets as read from the packet buffer cannot be stored in the fixed length frame to be transmitted out of the packet forwarding apparatus, and
 the fragment buffer temporarily stores at least a portion of the received variable length packet as read from the packet buffer in a case where the fragment signal is received.   
     
     
         5 . A network system having an optical fiber network connecting with an optical network terminal placed in a base side and an optical network unit placed in a subscriber side,
 wherein   the optical network terminal is connected to a core network;   the optical network terminal comprises an interface unit for transmitting and receiving a fixed length frame including a variable length packet, a packet switch for outputting a received variable length packet to the interface unit as a destination of the received variable length packet, and a traffic shaper for controlling timing of the packet transmission of the received variable length packet,   wherein the traffic shaper comprises a bandwidth control unit for controlling a to-be-transmitted bandwidth of the received variable length packet and a packet buffer for temporarily storing the received variable length packet, and   the traffic shaper stores a portion of the received variable length packet in another fixed length frame in a case where the received variable length packet as read from the packet buffer cannot be stored in the fixed length frame to be transmitted out of the packet forwarding apparatus.   
     
     
         6 . The network system according to  claim 5 , wherein the traffic shaper comprises a fragment buffer for temporarily storing the received variable length packet as read from the packet buffer, and
 the traffic shaper temporarily stores at least a portion of the received variable length packet in the fragment buffer in a case where the received variable length packet as read from the packet buffer cannot be stored in the fixed length frame to be transmitted out of the packet forwarding apparatus.   
     
     
         7 . The network system according to  claim 5 , wherein the traffic shaper comprises a read data length control unit for counting a quantity of data read from the packet buffer, and
 the read data length control unit determines whether or not the received variable length packet as read from the packet buffer can be stored in the fixed length frame to be transmitted out of the packet forwarding apparatus based on a counting result of the quantity of the data read from the packet buffer.   
     
     
         8 . The network system according to  claim 7 , wherein the read data length controller outputs a fragment signal to the fragment buffer in a case where the read data length controller determines that the received variable length packets as read from the packet buffer cannot be stored in the fixed length frame to be transmitted out of the packet forwarding apparatus, and
 the fragment buffer temporarily stores at least a portion of the received variable length packet as read from the packet buffer in a case where the fragment signal is received.