IOS Router Connectivity Options

IOS Router Connectivity: Dial In versus Dial Out

When setting up a telemetry ingestion pipeline between an IOS router and Provider Connectivity Assurance, you can choose the type of connectivity you want to use between your router and the Telemetry Collector. This article will explain the available methods (user interface and/or API) for configuring and deploying pipelines using either MDT Dial-Out or gNMI Dial-In connectivity.

The out-of-the-box solution uses MDT Dial-Out connectivity; the sections below explain the difference between Dial In and Dial Out, how to choose the best approach for your network, and provide configuration and deployment instructions for both options.

What is the Difference Between gNMI Dial-In and MDT Dial-Out Connectivity?

The main difference between these two modes lies in who initiates the gRPC connection used to stream telemetry data to the Telemetry Collector:

MDT Dial-Out Mode

In this mode, the router generating the telemetry data is responsible for initiating the gRPC connection to the Telemetry Collector.
The router must also be configured with sensor paths, destination groups, and subscription groups, which define how telemetry data is sent to the collector.

gNMI Dial-In Mode

Here, the Telemetry Collector is responsible for reaching out to the router to establish the gRPC connection.
The collector must also subscribe to specific sensor paths to receive the telemetry data it needs.

Once the connection is established, the behavior is the same for both modes: the router streams its telemetry data to the collector in the same format, regardless of which mode is used.

How Do You Choose Between gNMI Dial-In and MDT Dial-Out Connectivity?

The choice between the two depends on how you want to handle provisioning:

MDT Dial-Out Mode:
This requires configuring each router individually. If you have a large number of routers to set up (dozens or even hundreds), this method may be more time-consuming.

gNMI Dial-In Mode:
All provisioning is handled in the Telemetry Collector’s configuration. This can be a more centralized and efficient approach, especially for large-scale deployments.

Availability and Load Balancing Considerations

Another important consideration when deciding between Dial in and Dial out is how you want to handle load balancing and ensuring high availability.

Ultimately, the decision comes down to user preference and the specific requirements of your network.

By understanding the differences between these connectivity modes and the configuration methods, you can choose the approach that best suits your network’s needs and your level of expertise.