9 EP3499820B1 10 aspect,a method for determining,by the determining threshold and is less than or equal to the second preset module,the second sub stream set based on indication threshold(the second preset threshold is greater than of the ECE identifier may include:monitoring,by the de- the first preset threshold);and make a congestion mark termining module monitors in the preset time period,sub for the second data packet received by the receiving mod- streams in the first sub stream set that are other than a 5 ule,and add the second data packet to the data packet third sub stream in which the second data packet is lo- queue.The sending module is configured to successively cated in the set;detemmining,as a plurality of fourth sub send data packets (including the second data packet streams,sub streams that meet the congestion control added by the determining module to the data packet condition in the sub streams other than the third sub queue)in the data packet queue to the second device. stream in the first sub stream set;and determining the 10 [0049]For technical effects of the fifth aspect or any third sub stream and the plurality of fourth sub streams optional implementation of the fifth aspect,refer to related as the second sub stream set. descriptions of technical effects of the second aspect or [0043]In a sixth optional implementation of the fourth any optional implementation of the second aspect.De aspect,the determining module may be further config- tails are not described herein again. ured to mark a to-be-sent data packet before the sending 15 [0050]In the second aspect and the fifth aspect,the module sends the data packet to a routing device. first preset threshold may be determined by using the [0044]For technical effects of the fourth aspect or any optional implementation of the fourth aspect,refer to re- following formula:K,≥二C*RTT,where K,is the lated descriptions of technical effects of the first aspect or any optional implementation of the first aspect.Details 20 first preset threshold,C is a capacity of a link between are not described herein again. the first device and the second device(namely,a maxi- [0045]In the first aspect and the fourth aspect,the con- mum value of a data stream that can be transmitted on gestion control condition includes at least one of the fol- the link),and RTT is a round trip delay of a sub stream lowing three conditions:a delay of a sub stream is greater (namely,any one of a plurality of sub streams transmitted than a preset delay threshold;a packet loss event occurs 25 on the link)transmitted on the link in the sub stream;and the receiving module receives an [0051]The second preset threshold may be deter- acknowledgement packet of a data packet of the sub mined by using the following formula:K2>2*K1.where stream,and the acknowledgement packet of the data K,is the second preset threshold. packet of the sub stream includes the ECE identifier. [0052]In this application,the capacity of the link and [0046]In this application,the three congestion control 30 the round trip delay of the sub stream transmitted on the conditions can reflect congestion statuses of the plurality link can reflect a length of a data packet queue of the of sub streams transmitted on the plurality of transmis routing device.Therefore,when the first preset threshold sion paths between the first device and the second de- is calculated with reference to the capacity of the link and vice.Therefore,the routing device may determine,based the round trip delay of the sub stream transmitted on the on at least one of the three congestion control conditions, 35 link,the routing device can more accurately determine a sub stream that may be congested. whether the sub stream in which the first data packet is [0047]According to a fifth aspect,a routing device is located is congested. provided.The routing device includes a receiving mod- [0053]According to a sixth aspect,a device is provid- ule,a determining module.and a sending module.The ed.The device includes a receiving module,a determin- receiving module is configured to receive a first data 40 ing module,and a sending module.The receiving module packet from a first device.The determining module is is configured to receive a first data packet from a routing configured to:determine that an average queue length device.The determining module is configured to make of a data packet queue(the data packet queue includes an ECE mark for a first acknowledgement packet with a data packet to be from the routing device)is greater which the second device is to reply to a first device(name- than or equal to a first preset threshold and is less than 45 ly,an acknowledgement packet with which the second or equal to a second preset threshold;and make a con- device is to reply to the first data packet received by the gestion mark for the first data packet,and add the first receiving module).The sending module is configured to data packet to the data packet queue,where the second send the first acknowledgement packet marked by the preset threshold is greater than the first preset threshold. determining module to the first device. The sending module is configured to successively send 50 [0054]In a first optional implementation of the sixth data packets in the data packet queue to a second device. aspect,the receiving module is further configured to re- [0048]In a first optional implementation of the fifth as- ceive a second data packet from the routing device.The pect,the receiving module is further configured to receive determining module is further configured to make an ECE a second data packet from the first device.The deter- mark for a second acknowledgement packet with which mining module is further configured to:determine that an 55 the second device is to reply to the first device(namely. average queue length of a data packet queue(the data an acknowledgement packet with which the second de- packet queue includes a data packet to be from the rout- vice is to reply to the second data packet received by the ing device)is greater than or equal to the first preset receiving module).The sending module is further config-EP 3 499 820 B1 7 5 10 15 20 25 30 35 40 45 50 55 aspect, a method for determining, by the determining module, the second sub stream set based on indication of the ECE identifier may include: monitoring, by the de￾termining module monitors in the preset time period, sub streams in the first sub stream set that are other than a third sub stream in which the second data packet is lo￾cated in the set; determining, as a plurality of fourth sub streams, sub streams that meet the congestion control condition in the sub streams other than the third sub stream in the first sub stream set; and determining the third sub stream and the plurality of fourth sub streams as the second sub stream set. [0043] In a sixth optional implementation of the fourth aspect, the determining module may be further config￾ured to mark a to-be-sent data packet before the sending module sends the data packet to a routing device. [0044] For technical effects of the fourth aspect or any optional implementation of the fourth aspect, refer to re￾lated descriptions of technical effects of the first aspect or any optional implementation of the first aspect. Details are not described herein again. [0045] In the first aspect and the fourth aspect, the con￾gestion control condition includes at least one of the fol￾lowing three conditions: a delay of a sub stream is greater than a preset delay threshold; a packet loss event occurs in the sub stream; and the receiving module receives an acknowledgement packet of a data packet of the sub stream, and the acknowledgement packet of the data packet of the sub stream includes the ECE identifier. [0046] In this application, the three congestion control conditions can reflect congestion statuses of the plurality of sub streams transmitted on the plurality of transmis￾sion paths between the first device and the second de￾vice. Therefore, the routing device may determine, based on at least one of the three congestion control conditions, a sub stream that may be congested. [0047] According to a fifth aspect, a routing device is provided. The routing device includes a receiving mod￾ule, a determining module, and a sending module. The receiving module is configured to receive a first data packet from a first device. The determining module is configured to: determine that an average queue length of a data packet queue (the data packet queue includes a data packet to be from the routing device) is greater than or equal to a first preset threshold and is less than or equal to a second preset threshold; and make a con￾gestion mark for the first data packet, and add the first data packet to the data packet queue, where the second preset threshold is greater than the first preset threshold. The sending module is configured to successively send data packets in the data packet queue to a second device. [0048] In a first optional implementation of the fifth as￾pect, the receiving module is further configured to receive a second data packet from the first device. The deter￾mining module is further configured to: determine that an average queue length of a data packet queue (the data packet queue includes a data packet to be from the rout￾ing device) is greater than or equal to the first preset threshold and is less than or equal to the second preset threshold (the second preset threshold is greater than the first preset threshold); and make a congestion mark for the second data packet received by the receiving mod￾ule, and add the second data packet to the data packet queue. The sending module is configured to successively send data packets (including the second data packet added by the determining module to the data packet queue) in the data packet queue to the second device. [0049] For technical effects of the fifth aspect or any optional implementation of the fifth aspect, refer to related descriptions of technical effects of the second aspect or any optional implementation of the second aspect. De￾tails are not described herein again. [0050] In the second aspect and the fifth aspect, the first preset threshold may be determined by using the following formula: where K1 is the first preset threshold, C is a capacity of a link between the first device and the second device (namely, a maxi￾mum value of a data stream that can be transmitted on the link), and RTT is a round trip delay of a sub stream (namely, any one of a plurality of sub streams transmitted on the link) transmitted on the link. [0051] The second preset threshold may be deter￾mined by using the following formula: K2 ≥ 2 ∗ K1, where K2 is the second preset threshold. [0052] In this application, the capacity of the link and the round trip delay of the sub stream transmitted on the link can reflect a length of a data packet queue of the routing device. Therefore, when the first preset threshold is calculated with reference to the capacity of the link and the round trip delay of the sub stream transmitted on the link, the routing device can more accurately determine whether the sub stream in which the first data packet is located is congested. [0053] According to a sixth aspect, a device is provid￾ed. The device includes a receiving module, a determin￾ing module, and a sending module. The receiving module is configured to receive a first data packet from a routing device. The determining module is configured to make an ECE mark for a first acknowledgement packet with which the second device is to reply to a first device (name￾ly, an acknowledgement packet with which the second device is to reply to the first data packet received by the receiving module). The sending module is configured to send the first acknowledgement packet marked by the determining module to the first device. [0054] In a first optional implementation of the sixth aspect, the receiving module is further configured to re￾ceive a second data packet from the routing device. The determining module is further configured to make an ECE mark for a second acknowledgement packet with which the second device is to reply to the first device (namely, an acknowledgement packet with which the second de￾vice is to reply to the second data packet received by the receiving module). The sending module is further config- 9 10