Streaming telemetry allows users to monitor network health by efficiently streaming operational data of interest from OcNOS routers. This structured data is transmitted to remote management systems for proactive network monitoring and understanding CPU and memory usage in managed devices for troubleshooting.

A machine learning (ML) database can be created with telemetry data to establish a baseline for normal network operation and predict or mitigate network issues.

OcNOS version 6.4.1 introduces the initial features for Streaming Telemetry, which include support for gNMI-based Dial-in mode Telemetry for the management plane. The initial feature list includes support for the “STREAM” type and “SAMPLING” mode subscription for the Subscribe Remote Procedure Call (RPC). The gNMI-based collector connects to the OcNOS target device and invokes the Subscribe RPC, specifying the set of path(s) of interest. Below are the two key components involved:

Figure 1 illustrates the gNMI client's (Collector) Subscribe request and response (RPC) interaction with the gNMI server (OcNOS Target).

Dial-in Mode: Dial-in mode is the method used to establish a telemetry connection where the collector initiates the connection to the server. In this mode, the collector sends a Subscribe RPC request to the target device, and the server running on the target device streams the data to the collector.

Figure 2 illustrates a sample gnmic Subscribe Request and Subscribe Response between the collector and the OcNOS target device.

To limit the impact of telemetry on critical features of the OcNOS target device, certain limits have been implemented. In Stream mode, there is a maximum limit of 100 sensor paths that can be subscribed to at any given point in time. Additionally, the minimum supported sample interval is 10 seconds.

Minimum Sample Interval: The minimum supported sample interval is 10 seconds. Any sampling mode request with a sample interval of less than 10 seconds will result in an error. However, if a sample interval is 0, it defaults to the minimum sample interval supported by the gNMI server, which is 10 seconds.

Proactive Network Monitoring: Obtain real-time insights into network health and performance, and how to enable quicker response to issues.

Resource Utilization Monitoring: Monitor CPU and memory utilization to optimize resource allocation and performance.

Predictive Troubleshooting: Identify patterns and potential issues before they impact the network, reducing downtime.

Automation and Resilience: Use telemetry data to automate network management tasks and design a more resilient network.

Before configuring Streaming Telemetry, ensure that:

In this example, streaming telemetry with OcNOS is demonstrated, using 'gnmic' as the gNMI Client.

gNMI Specification can be found at: https://github.com/openconfig/reference/blob/master/rpc/gnmi/gnmi-specification.md

The 'gnmic' tool is available at: https://github.com/openconfig/gnmic

To install gnmic, use the following command:

To enable streaming telemetry on OcNOS:

Use the gnmic command with a YAML file input to request telemetry subscriptions with multiple paths.

This command establishes a telemetry subscription with the specified paths defined in the YAML file.

Use the gnmic command with a single path option to request a telemetry subscription for a specific data path.

This command creates a telemetry subscription for the specified path with the chosen sample interval and encoding format.

The below table explains the option fields.

In this use case, gnmic subscribes to a specific path using the Subscribe RPC, monitoring the state of an interface with the path 'ipi:/interfaces/interface[name=ce51]/state'.

The output of the Subscribe RPC includes the following information:

The below show command provides details about the subscriptions that have been established, including the client ID, sampling interval, encoding type, and the sensor paths that are being monitored.

In this use case, gnmic subscribes to a specific path using the Subscribe RPC, monitoring the state of an interface with the multiple path 'ipi:/interfaces/interface[name=ce51]/state' and 'ipi:/interfaces/interface[name=ce52]/state'.

The below show command provides details about the subscriptions that have been established, including the client ID, sampling interval, encoding type, and the sensor paths that are being monitored.

This use case illustrates the configuration of a subscription request with multiple paths using a YAML file input. It streamlines the subscription setup process by specifying the desired paths and subscription parameters directly in the YAML file.

The below show command provides details about the subscriptions that have been established, including the client ID, sampling interval, encoding type, and the sensor paths that are being monitored.

This use case illustrates the configuration of multiple subscription request with multiple paths using a YAML file input. It streamlines the subscription setup process by specifying the desired paths and subscription parameters directly in the YAML file.

The below show command provides details about the subscriptions that have been established, including the client ID, sampling interval, encoding type, and the sensor paths that are being monitored.

This use case illustrates the configuration of multiple subscription request with prefix option using a YAML file input. It streamlines the subscription setup process by specifying the desired paths and subscription parameters directly in the YAML file.

The below show command provides details about the subscriptions that have been established, including the client ID, sampling interval, encoding type, and the sensor paths that are being monitored.

Streaming telemetry incrementally supports all IPI datamodels, with OcNOS version 6.4.1 introducing support for two IPI datamodels listed below. Telemetry supports only operational containers and a subset of leaf attributes. The Pyang tree output below illustrates the supported containers or leaves, along with a list of supported container-level paths.

The below section lists the container level sensor paths and leaf attributes supported for telemetry.

The paths listed below represent telemetry paths for monitoring the state of various components, including CPU, storage, RAM, power supply, fans, fan trays, and transceivers.

Streaming Telemetry can be used in conjunction with other network monitoring and management features.

The Streaming Telemetry introduces the following configuration commands.

Use this command to enable or disable debugging information for CML streaming telemetry.

None

By default, debugging information is disabled.

Exec Mode

This command was introduced in OcNOS version 6.4.1.

The following example illustrates how to enable and disable the telemetry debugging information.

Use this command to enable or disable gNMI server debugging logs with severity levels.

By default, this command is disabled, and the gNMI server debugging level in the disabled state is set to the Error level.

Configure Mode

This command was introduced in OcNOS version 6.4.1.

The following example illustrates how to enable and disable the telemetry debug logs and their corresponding show output.

Use this command to enable the streaming telemetry and, upon configuration, to start the gNMI server. The gNMI server initiates listening for incoming gRPC connections on port 11162.

Use the no parameter of this command to disable the streaming telemetry, It will stop the gNMI server.

None

By default, the streaming-telemetry feature is disabled.

Configure mode

This command was introduced in OcNOS version 6.4.1.

The following example illustrates how to enable the streaming telemetry.

Use this command to display streaming telemetry status in the running configuration.

None

Exec mode and Configuration Mode

This command was introduced in OcNOS version 6.4.1.

The following example shows the streaming telemetry status in the show running-config output.

Use this command to display the streaming telemetry dial-in configurations.

None

Exec mode

This command was introduced in OcNOS version 6.4.1.

The following example displays the streaming telemetry dial-in configuration output.

The below table explains the output fields.

Follow the below troubleshooting steps, to debug telemetry related issues:

Verify Collector (gnmic) Command Options: Verify the input parameters, such as the sensor path, prefix and origin “ipi:”.

Check the Encoding Method Compatibility: Check that the request conforms to the supported JSON-IETF encoding method.

Ensure Proper Connectivity: Validate the connectivity between the router and the remote management system. This involves verifying network settings, ports, firewalls, and any potential disruptions in communication.

Collector: If gnmic does not receive a response or not receiving expected response, restart the request using the “--log” option. If more verbose debug output is needed, consider adding the “--debug” option as well. The gnmic tool displays the possible cause for any error, which helps in debugging the issue.

gNMI Server: If the issue is on server side, follow the steps below to troubleshoot telemetry issues on the OcNOS target. Enable debug and verify the logs in /var/log/messages file.

The following are some key abbreviations and their meanings relevant to this document:

The following provides definitions for key terms used throughout this document.