In-band edge-to-edge round-trip time measurement

1 . A method implemented by a network edge node, comprising:

adding a first in-situ operations, administration, and maintenance (IOAM) edge-to-edge (E2E) option header including a flags field and an IOAM E2E option data field including a first metadata to a first IOAM E2E option packet;

setting a first flag in the flags field of the IOAM E2E option packet to a first value to indicate that the first IOAM E2E option packet is a forward flow packet;

transmitting the first IOAM E2E option packet towards a second network edge node;

receiving a second IOAM E2E option packet including the first metadata in the IOAM E2E option data field and a second flag in the flags field set to the same first value as the first flag to indicate that the second IOAM E2E option packet is a reverse flow packet;

generating a second metadata corresponding to receipt of the second IOAM E2E option packet; and

transmitting an export message that includes the first metadata and the second metadata toward a controller.

2 . The method of claim 1 , wherein the IOAM E2E option header is added to the first IOAM E2E option packet in accordance with an instruction received from the controller.

3 . The method of claim 1 , wherein the IOAM E2E option header further comprises a namespace-id field and an IOAM E2E type field.

4 . The method of claim 3 , wherein the flags field is a part of the namespace-id field in the IOAM E2E option header.

5 . The method of claim 1 , wherein the flags field is a new field that is added in the first IOAM E2E option packet, and wherein the flags field comprises a plurality of flags including the first flag and the second flag.

6 . The method of claim 1 , wherein the first metadata comprises a first identifier and/or a first timestamp corresponding to the first IOAM E2E option packet, wherein the first identifier comprises a sequence number or a random number, and wherein the first timestamp represents a time at which the first IOAM E2E option packet was received by the network edge node.

7 . The method of claim 1 , further comprising generating, by a clock at the network edge node, a first timestamp corresponding to the first IOAM E2E option packet.

8 . The method of claim 1 , wherein the second metadata comprises a second timestamp corresponding to the second IOAM E2E option packet, and wherein the second timestamp represents a time at which the second IOAM E2E option packet was received by the network edge node.

9 . The method of claim 8 , further comprising:

transmitting a first timestamp corresponding to the first IOAM E2E option packet and the second timestamp to the controller, wherein the first timestamp represents a time at which the first IOAM E2E option packet was received by the network edge node; and

determining a round-trip time (RTT) between the network edge node and the second network edge node based on a difference between the first timestamp and the second timestamp, wherein the network edge node is an ingress network edge node, and wherein the second network edge node is an egress network edge node.

10 . The method of claim 1 , further comprising filtering and periodically selecting target packets including the first IOAM E2E option packet from a packet flow based on predetermined parameters, wherein the filtering includes access control list (ACL) filtering.

11 . A method implemented by a network edge node, comprising:

adding a header including a flags field and a data field including a first metadata to a first packet;

setting a first flag in the flags field of the header to a first value to indicate that the first packet is a forward flow packet;

transmitting the first packet towards a second network edge node;

receiving a second packet including the first metadata in the data field and a second flag in the flags field set to the same first value as the first flag to indicate that the second packet is a reverse flow packet;

generating a second metadata corresponding to receipt of the second packet; and

transmitting an export message that includes the first metadata and the second metadata toward a controller.

12 . The method of claim 11 , wherein the header is added to the first packet in accordance with an instruction received from the controller.

13 . The method of claim 11 , wherein the flags field is a part of an existing field in the header of the first packet or a new field that is added in the first packet.

14 . The method of claim 11 , wherein the header is an in-situ operations, administration, and maintenance (IOAM) edge-to-edge (E2E) option header.

15 . The method of claim 11 , further comprising generating, by a clock at the network edge node, a first timestamp corresponding to the first packet, wherein the first timestamp represents a time at which the first packet was received by the network edge node.

16 . The method of claim 11 , wherein the second metadata comprises a second timestamp corresponding to the second packet, and wherein the second timestamp represents a time at which the second packet was received by the network edge node.

17 . The method of claim 16 , further comprising:

transmitting a first timestamp corresponding to the first packet and the second timestamp to the controller, wherein the first timestamp represents a time at which the first packet was received by the network edge node; and

determining a round-trip time (RTT) between the network edge node and the second network edge node based on a difference between the first timestamp and the second timestamp, wherein the network edge node is an ingress network edge node, and wherein the second network edge node is an egress network edge node.

18 . A network edge node, comprising:

a memory configured to store instructions; and

a processor coupled to the memory and configured to execute the instructions to cause the network edge node to:

add a first in-situ operations, administration, and maintenance (IOAM) edge-to-edge (E2E) option header including a flags field and an IOAM E2E option data field including a first metadata to a first IOAM E2E option packet;

set a first flag in the flags field of the IOAM E2E option packet to a first value to indicate that the first IOAM E2E option packet is a forward flow packet;

transmit the first IOAM E2E option packet towards a second network edge node;

receive a second IOAM E2E option packet including the first metadata in the IOAM E2E option data field and a second flag in the flags field set to the same first value as the first flag to indicate that the second IOAM E2E option packet is a reverse flow packet;

generate a second metadata corresponding to receipt of the second IOAM E2E option packet; and

transmit an export message that includes the first metadata and the second metadata toward a controller.

19 . The network edge node of claim 18 , wherein the IOAM E2E option header is added to the first IOAM E2E option packet in accordance with an instruction received from the controller.

20 . The network edge node of claim 18 , wherein the IOAM E2E option header further comprises a namespace-id field and an IOAM E2E type field.