| 摘要 |
PURPOSE: A router congestion information relaying method for ECN(Explicit Congestion Notification) on the Internet is provided to immediately relay congestion information delivered from a front router as well as congestion information of a current router to the next router, so as to largely reduce packet losses due to buffer overflow. CONSTITUTION: In the case of the inflow of an IP(Internet Protocol) packet from a front-router(S41), a traffic controller checks the CE bit of the IP packet(S42). If the CE bit indicates 1(one), the traffic controller sets a RELAYED_CE flag of corresponding connection of a data table to 1(one)(S43) and resets the CE bit of the corresponding packet to prevent identical congestion from being delivered twice(S44). If the CE bit indicates 0(zero) in the step S42, the traffic controller sets a RELAYED_CE flag of corresponding connection of the data table to 0(zero)(S45). In the case of the outflow of an IP packet from a buffer of a current router, the traffic controller decides a CURRENT_CE value according to congestion states of the current router. The traffic controller performs an OR operation for the decided CURRENT_CE value and a RELAYED_CE value relayed from the front-router for corresponding connection and stored in the data table, to calculate a CE value. The traffic controller decides whether a calculated result is a high level, or 0(one). If so, the traffic controller sets the CE bit of the IP packet to 1(one), and if not, the traffic controller delivers the IP packet to an after-router intactly.
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