Apparatus and method for packet transmission
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsMasayuki Kumazawa, Mikio Shimazu, Yuji Shimizu
Life of this patent
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Abstract
A packet transmission apparatus transfers arriving packets directly to a highest-priority queue under non-congestion conditions, and classifies the priority of a packet only on the existence of congestion. In one embodiment, non-congestion is determined when all queues are empty. In another embodiment, congestion or non-congestion is determined by upper and lower thresholds on the total number of packets in all queues. The ability to omit classifying incoming packets in the non-congestion condition improves processing speed, and eliminates the need for re-queuing or packet-replacing operations.
Claims16
A packet transmission apparatus comprising:
- a plurality of queues each having a different priority;
- a packet transmitting unit operable to extract a packet from any one of said plurality of queues, thereby transmitting the extracted packet;
- a packet receiving unit operable to receive a packet that has arrived;
- a transferring unit operable to transfer the packet received at said packet receiving unit;
- a classifying device operable to transfer the packet transferred from said transferring unit to any one of said plurality of queues in accordance with a priority of the packet transferred from said transferring unit;
- and
- a controlling unit operable to judge whether said plurality of queues is in a congestion state or in a non-congestion state,
- wherein said transferring unit is further operable to alternatively transfer the packet received by said packet receiving unit directly to any one of said plurality of queues in the non-congestion state and transfer the packet received by said packet receiving unit to said classifying device in the congestion state.
A packet transmission method comprising:
- establishing at least first and second queues, each queue having a different priority;
- extracting a packet from at least one of the first and second queues, thereby transmitting the extracted packet;
- receiving a packet that has arrived;
- judging whether at least one of the first and second queues is in a congestion state or in a non-congestion state;
- transferring alternatively the received packet directly to any one of the first and second queues in the non-congestion state;
- and
- transferring the received packet to a classifying device and then to any one of the first and second queues by classifying the received packet in accordance with a priority of the packet in the congestion state.
The packet transmitting method comprising:
- establishing at least first and second queues;
- extracting a packet from at least one of the first queue and the second queue, thereby transmitting the extracted packet;
- receiving a packet that has arrived;
- judging whether at least one of the first queue and the second queue is in a congestion state or in a non-congestion state;
- and
- transferring alternatively the received packet directly to any one of the first queue and the second queue in the non-congestion state, and transferring the received packet to any one of the first queue and the second queue by classifying in accordance with a priority of the packet in the congestion state;
- and
- switching a priority of a queue having a highest priority prior to being switched to a lowest priority when an entire length of all of said at least first and second of queues does not exceed a fixed threshold, wherein when all queues except said queue having said lowest priority are empty in this state, said judging judges that at least one of said first queue and said second queue is in the non-congestion state.
Dependencies are inferred from the claim text.