Multicast in-band telemetry system and method

Patent metadata

Field	Value
Publication number	US-12470471-B2
Application number	US-202318102460-A
Country	US
Kind code	B2
Filing date	Jan 27, 2023
Priority date	Jan 27, 2023
Publication date	Nov 11, 2025
Grant date	Nov 11, 2025

Abstract

In-band network telemetry for multicast is provided by injecting a synthetic telemetry packet into the multicast. Each first node of each branch replicates the synthetic packet and passes on copy to the next branch and sends one copy down the nodes in the branch sequentially. The synthetic telemetry packet can include flags with have values, including, for example, whether each node should hold or send data collected by the node according to the synthetic data packet, how long a node is to hold collected telemetry data, and what data to collect. The node sends a postcard to the originator with the telemetry data according to the instructions in the synthetic telemetry packet.

First claim

What is claimed is:

1 . A method of collecting telemetry in a multicast network having a first branch and a second branch, each branch comprising a plurality of sequential nodes, the plurality of sequential nodes including an initial branch node and a destination device, the method comprising:
injecting a synthetic telemetry packet into the multicast network at the initial branch node of the first branch; the initial branch node transmitting the synthetic telemetry packet to a next sequential node of the first branch, wherein each sequential node transmits the synthetic telemetry packet to a next sequential node in the first branch until the synthetic telemetry packet reaches the destination device of the first branch; the initial branch node of the first branch replicating the synthetic telemetry packet and transmitting the replicated synthetic telemetry packet to the initial branch node of the second branch; and the initial branch node of the second branch transmitting the replicated synthetic packet to a next sequential node of the second branch, wherein each sequential node of the second branch transmits the synthetic telemetry packet to a next sequential node in the second branch until the synthetic telemetry packet reaches the destination device of the second branch; wherein the synthetic packet defines which nodes of the plurality of sequential nodes are to collect telemetry, parameters for collecting telemetry and instructions for transmitting collected telemetry.

2 . The method of claim 1 , wherein each node that receives the synthetic packet or the replicated synthetic packet processes the packet and acts on the instructions in the packet with respect to that receiving node.

3 . The method of claim 2 , wherein the instructions in the packet include an instruction for at least one of the plurality of sequential nodes to transmit a report from the at least one of the plurality of sequential nodes directly to an off-path device.

4 . The method of claim 3 , wherein the report comprises telemetry.

5 . The method of claim 2 , wherein the instructions in the packet include an instruction for at least one of the plurality of sequential nodes to collect telemetry.

6 . The method of claim 1 , wherein the instructions in the synthetic packet do not include an instruction for at least one of the plurality of sequential nodes to transmit a report.

7 . The method of claim 4 , wherein the telemetry includes a node identifier, and at least one of jitter, path, timestamp and latency at the at least one node, packet drop location and reason in case of packet drop.

8 . The method of claim 1 wherein the instructions in the packet include an instruction for at least one of the plurality of sequential nodes to transmit a report.

9 . The method of claim 1 , further comprising each sequential node processing the packet before transmitting to the next sequential node.

10 . The method of claim 1 , wherein the synthetic packet comprises a header including which nodes of the plurality of sequential nodes are to collect telemetry, the parameters for collecting telemetry and the instructions for transmitting the collected telemetry.

11 . A method for transmitting from a node in a multicast network, the node being one of a plurality of sequential nodes in a single branch of a plurality of parallel branches of the multicast network, the method comprising:
receiving a synthetic telemetry packet, wherein a replicated synthetic telemetry packet traverses another branch of the multicast network and the synthetic telemetry packet includes instructions for the node to transmit telemetry directed to a receiver external to the single branch; and upon receipt of the instruction, the node transmitting the telemetry to the receiver and forwarding the synthetic telemetry packet to a next node in the single branch or to a destination device in the branch.

12 . The method of claim 11 , wherein the telemetry includes a node identifier, and at least one of jitter, path, timestamp and latency at the at least one node, packet drop location and reason in case of packet drop.

13 . The method of claim 11 , wherein the instructions in the synthetic telemetry packet include an instruction for at least one of the plurality of sequential nodes to transmit a report.

14 . The method of claim 11 , wherein the instructions in the synthetic telemetry packet does not include an instruction for at least one of the plurality of sequential nodes to transmit a report.

15 . The method of claim 11 , wherein the synthetic telemetry packet comprises a header including which nodes of the plurality of sequential nodes are to collect telemetry, parameters for collecting telemetry and the instructions for transmitting the telemetry.

16 . A node in a branch of a multicast network configured to collect telemetry data, comprising:
a receiver configured to receive a synthetic telemetry packet containing an instruction header; and a processor coupled to the receiver, the processor configured to: collect the telemetry data at the node as instructed by the instruction header; and determine whether the synthetic telemetry packet comprises an instruction for the node to transmit the telemetry data to an external device; the node further comprising: a transmitter coupled to the processor, the transmitter configured to transmit the telemetry data to the external device according to instructions in the synthetic telemetry packet upon determination that the synthetic telemetry packet comprises an instruction for the node to transmit the telemetry data and to transmit the synthetic telemetry packet to a next node in or a destination device of the branch of the multicast network.

17 . The node of claim 16 , wherein the synthetic telemetry packet is received from an upstream node in the branch of the multicast network.

18 . The node of claim 16 , wherein the synthetic telemetry packet is replicated in other branches of the multicast network.

19 . The node of claim 16 , wherein the synthetic telemetry packet includes instructions for multiple nodes within the multicast network to send telemetry data to the external device.

20 . The node of claim 16 , wherein the synthetic packet does not include an instruction for at least one of a plurality of sequential nodes to transmit a report.

Assignees

• Cisco Tech Inc

Inventors

• Mishra Mankamana Prasad
• Bhagwatula Praveen
• Kumar Nitin
• Ananthamurthy Krishnaswamy

Classifications

• H04L12/18

  for broadcast or conference {, e.g. multicast} · CPC title

• H04L43/06

  Generation of reports · CPC title

• H04L43/0829

  Packet loss · CPC title

• H04L43/087

  Jitter · CPC title

• H04L43/0852

  Delays · CPC title