| 摘要 |
An egress speed control device in a packet-switched communication network and a controlling method thereof are provided to dynamically allocate a surplus rate, which is not allocated to other VPs(Virtual Pipes), to a particular VP if the currently available bandwidth remains even though the particular VP exceeds a shaping rate, so that the particular VP can transmit traffic. A token counter generates a token trigger signal. A token rate generator generates tokens according to the token trigger signal. A token bucket stores the generated tokens. A token comparator compares the number of the stored tokens with the current packet length. A setup variable storage sets a variable for calculating a surplus rate, and stores the set variable. A surplus rate operator operates the surplus rate. A surplus rate decider decides whether packet transmission is available by using the operated results. A packet transmitter transmits a packet according to the compared results and the decided results. A token bucket re-calculator updates the number of tokens remaining in the token bucket after the packet is transmitted. A current surplus rate and current link bandwidth re-calculator updates the current link bandwidth which is a value produced by adding length of packets before the packet transmission at the current point of time for ports during a token window and the current surplus rate which is a rate that a particular VP sends a packet by exceeding during the token window after the packet transmission by the surplus rate. |
