Mechanisms for packet path tracing and per-hop delay measurement in segment routing with multiprotocol label switching (SR-MPLS) networks
A network node receives a data packet. In response to receiving the data packet, the network node performs a lookup on a label stack of the data packet to determine a next hop for the data packet. The network node scans the label stack to identify a Structured Entropy Label (SEL). The SEL includes a Path Tracing Indicator (PTI). The network node computes Midpoint Compressed Data (MCD) as a result of the PTI being set to a pre-defined value. The network node records the MCD in a MCD stack of the data packet by shifting the MCD stack and stamping the MCD on top of the MCD stack. The network node transmits the data packet to the next hop with the recorded MCD stack. The network sink node encapsulates the received data packet to generate an encapsulated data packet and transmits the data packet.
1. A computer-implemented method comprising:
receiving a data packet;
performing a Multiprotocol Label Switching (MPLS) lookup on a label stack of the data packet to determine a next hop for the data packet;
scanning the label stack to identify a label, wherein the label includes a field comprising a path tracing indicator (PTI);
computing midpoint compressed data (MCD), wherein the MCD is computed as a result of the PTI in the label stack being set to a pre-defined value;
recording the MCD in a MCD stack of the data packet, wherein the MCD is recorded by shifting the MCD stack by a number of bytes equal to a size of the MCD and stamping the MCD on top of the MCD stack; and
transmitting the data packet to the next hop.
2. The computer-implemented method of claim 1 , wherein the data packet includes instructions for computing and recording the MCD in the data packet.
3. The computer-implemented method of claim 1 , wherein an entropy label control (ELC) field of a structured entropy label (SEL) in the label stack is used to determine a path tracing action for the data packet.
4. The computer-implemented method of claim 1 , wherein the label stack of the data packet includes a timestamp, encapsulate, and forward (TEF) label that causes a sink node receiving the data packet to:
encapsulate the data packet to generate an encapsulated data packet; and
send the encapsulated data packet to a collector.
5. The computer-implemented method of claim 1 , wherein a network programming label is used to determine a path tracing action for the data packet, and wherein the network programming label includes one or more fields that are used to determine the path tracing action.
6. The computer-implemented method of claim 1 , wherein the PTI is set at a source node to trigger a path tracing action at midpoint nodes.
7. The computer-implemented method of claim 1 , wherein the label stack of the data packet further defines a channel type, wherein the channel type indicates a format of a message that follows a generic associated channel (G-ACH) in the label stack, and wherein the format is the MCD stack and a source node Type-Length-Value (TLV).
8. A system, comprising:
one or more processors; and
memory storing thereon instructions that, as a result of being executed by the one or more processors, cause the system to:
receive a data packet;
perform a Multiprotocol Label Switching (MPLS) lookup on a label stack of the data packet to determine a next hop for the data packet;
scan the label stack to identify a label, wherein the label includes a field comprising a path tracing indicator (PTI);
compute midpoint compressed data (MCD), wherein the MCD is computed as a result of the PTI in the label stack being set to a pre-defined value;
record the MCD in a MCD stack of the data packet, wherein the MCD is recorded by shifting the MCD stack by a number of bytes equal to a size of the MCD and stamping the MCD on top of the MCD stack; and
transmit the data packet to the next hop.
9. The system of claim 8 , wherein the data packet includes additional instructions for computing and recording the MCD in the data packet.
10. The system of claim 8 , wherein an entropy label control (ELC) field of a structured entropy label (SEL) in the label stack is used to determine a path tracing action for the data packet.
11. The system of claim 8 , wherein the label stack of the data packet includes a timestamp, encapsulate, and forward (TEF) label that causes a sink node receiving the data packet to:
encapsulate the data packet to generate an encapsulated data packet; and
send the encapsulated data packet to a collector.
12. The system of claim 8 , wherein a network programming label is used to determine a path tracing action for the data packet, and wherein the network programming label includes one or more fields that are used to determine the path tracing action.
13. The system of claim 8 , wherein the PTI is set at a source node to trigger a path tracing action at midpoint nodes.
14. The system of claim 8 , wherein the label stack of the data packet further defines a channel type, wherein the channel type indicates a format of a message that follows a generic associated channel (G-ACH) in the label stack, and wherein the format is the MCD stack and a source node Type-Length-Value (TLV).
15. A non-transitory, computer-readable storage medium storing thereon executable instructions that, as a result of being executed by one or more processors of a computer system, cause the computer system to:
receive a data packet;
perform a Multiprotocol Label Switching (MPLS) lookup on a label stack of the data packet to determine a next hop for the data packet;
scan the label stack to identify a label, wherein the label includes a field comprising a path tracing indicator (PTI);
compute midpoint compressed data (MCD), wherein the MCD is computed as a result of the PTI in the label stack being set to a pre-defined value;
record the MCD in a MCD stack of the data packet, wherein the MCD is recorded by shifting the MCD stack by a number of bytes equal to a size of the MCD and stamping the MCD on top of the MCD stack; and
transmit the data packet to the next hop.
16. The non-transitory, computer-readable storage medium of claim 15 , wherein the data packet includes additional instructions for computing and recording the MCD in the data packet.
17. The non-transitory, computer-readable storage medium of claim 15 , wherein an entropy label control (ELC) field of a structured entropy label (SEL) in the label stack is used to determine a path tracing action for the data packet.
18. The non-transitory, computer-readable storage medium of claim 15 , wherein the label stack of the data packet includes a timestamp, encapsulate, and forward (TEF) label that causes a sink node receiving the data packet to:
encapsulate the data packet to generate an encapsulated data packet; and
send the encapsulated data packet to a collector.
19. The non-transitory, computer-readable storage medium of claim 15 , wherein a network programming label is used to determine a path tracing action for the data packet, and wherein the network programming label includes one or more fields that are used to determine the path tracing action.
20. The non-transitory, computer-readable storage medium of claim 15 , wherein the PTI is set at a source node to trigger a path tracing action at midpoint nodes.