Detection packet transmission method, apparatus, and system

A first network device that is a first edge network device in a first network domain, the first network device comprising:

• a non-transitory memory configured to store instructions;
• and
• one or more processors coupled to the non-transitory memory and configured to execute the instructions to cause the first network device to:
• receive a first packet of a service flow, wherein the first packet comprises a detection header instructing detection of, based on the detection header, a transmission performance of the service flow, wherein the transmission performance is service-level agreement (SLA) performance, a number of lost packets in the service flow, or a transmission delay of a packet in the service flow;
• obtain, based on the first packet, a second packet comprising processing identification information and the detection header, wherein the processing identification information instructs processing of the detection header;
• and
• send the second packet to a second network device that is outside the first network domain and that is a next-hop device of the first network device on a transmission path of the service flow.

A second network device outside a first network domain and comprising:

• a non-transitory memory configured to store instructions;
• and
• one or more processors coupled to the non-transitory memory and configured to execute the instructions to cause the second network device to:
• receive a second packet from a first network device that is an edge network device in the first network domain such that the second network device is a next-hop device of the first network device on a transmission path of a service flow, wherein the second packet is based on a first packet of the service flow, wherein the second packet comprises processing identification information and a detection header, wherein the processing identification information instructs the second network device to process the detection header, and wherein the detection header instructs detection of a transmission performance of the service flow, wherein the transmission performance is service-level agreement (SLA) performance, a number of lost packets in the service flow, or a transmission delay of a packet in the service flow;
• and
• detect the transmission performance of the service flow based on the processing identification information and the detection header.