Service flow shaping method and device for cascaded port of avionics full duplex switched Ethernet (AFDX) switch

Abstract

The invention discloses a service flow shaping method and a service flow shaping device for a cascaded port of an avionics full duplex switched Ethernet (AFDX) switch. The main problems of relatively stronger switching delay jitter of packets and incapability of transmitting high-priority packets on time in the prior art are solved, and a system can be conveniently cascaded. The method comprises the following steps of: (1) extracting packet scheduling information; (2) extracting the information of a time registry; (3) receiving and scheduling the packets; (4) selecting and sequencing the packets; (5) updating time tags; (6) transmitting and scheduling the packets; and (7) updating a time registry. The device comprises an input caching module, a receiving scheduling module, a time registry module, a packet information storage area module, a time tag module, an output queue module, a transmission scheduling module and an output caching module. The method and the device have the advantages that: the determinacy of the delay jitter of the packets can be ensured; the forwarding delay jitter of the packets can be effectively reduced; the high-priority packets can be transmitted on time; and the method and the device are applied to the traffic shaping of the AFDX switch.

Description

technical field [0001] The invention belongs to the technical field of communications, and further relates to a service flow shaping method and device for a cascaded port of an aviation full duplex Ethernet (Avionics Full Duplex Switched Ethernet, AFDX) switch. The invention can be used in traffic shaping, can reduce delay jitter introduced by packet switching and ensure timely sending of high-priority packets within the delay range allowed by the system, and is convenient for system cascading. Background technique [0002] In packet data switches, switching delay and delay jitter usually need to be controlled below a certain value to meet the higher requirements of user services. In some special applications, the delay jitter introduced by the packet forwarding through the switch is not only required to be as small as possible, but also must be deterministic. With the development of aerospace technology, data switches will be used in aircraft, spacecraft and other aircraft...

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Problems solved by technology

[0004] The disadvantage of this method is that it does not consider the problem that the packet exchange delay may be large under the condition of heavy traffic load, which may cause the delay of the packet with relatively high real-time requirements to be too large; In the process, the concept of expected sending time is introduced, which may lead to the problem of large delay jitter in forwarding packets by switches; the determination method of packet priority is based on the deadline for packets to enter the virtual output queue, and is related to the business flow The real-time performance is irrelevant. When the real-time packet arrives at the AFDX switch later than the non-real-time packet, the priority of the real-time packet may be reduced, and the real-time performance cannot be guaranteed; the scheduling method mentioned in it does not perform shaping processing, and there is no coordination high, The output scheduling of low-priority packets is only to reduce the forwarding delay of high-priority packets as much as possible, which will not meet the requirements of AFDX packet transmission arrival time determinism

[0006] The disadvantage of this method is that the sending scheduling method will introduce a large waiting delay at the source end, and the data packets to be sent need to wait for their virtual link counter to time out before sending, which may introduce too large a delay to the real-time packets. time delay

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