When you configure a telemetry subscription, you specify a set of statistics data and notification and storage options for the data. To configure the data set, select the type of statistics you are interested in, the frequency of collection, and configure filtering by NE and counters as needed.

Statistics collection requirements and behavior depend on the NE management type and statistics type, as described in the following table.

Notes:

1. If statistics collection is set up in both NFM-P and NSP, the telemetry framework may receive the same information twice. The duplication could result in incorrect reports or duplicated indicator TCAs. Verify that the data being used for telemetry, baseline, or indicator subscriptions is only collected once. See “Troubleshooting duplicate data collection” in the NSP Troubleshooting Guide for more information.

You can enable database storage for MDM- managed NEs as part of subscription creation. By default, the data collected is stored in Postgres unless there is an auxiliary database enabled, in which case all collected data is stored in the auxiliary database. For telemetry data that is collected by NFM-P, the database parameter in the subscription is ignored.

Historical data, that is, data that is stored in a database, is retained according to the age-out policy; see How do I edit an age-out policy?.

Note: For telemetry data to be available to the Analytics application for aggregated reports, it must be stored in the auxiliary database.

The Telemetry data API also provides the functionality to subscribe, stream, and plot historical and real-time data; see Use Case 5 in the Telemetry Collection tutorial on the Network Developer Portal.

You can enable file subscriptions to save accounting statistic information to a file. Files can be managed from the File Server; see How do I retrieve accounting files?.

The directory path for file output is configured as part of subscription creation.

If the Directory Path for File Output parameter is left blank, accounting files will be saved to accounting/output/ready/NE ID/date.

If a path is entered, the path folders are created in the accounting/output/ready directory. For example, if you enter new/files, the path to the files is accounting/output/ready/new/files/NE ID/date.

The path can include any number of subdirectories.

Note: Accounting files that are migrated from Release 25.8 or earlier are placed in accounting/output/ready/. These files are not organized by NE ID and date.

You can enable notifications in the subscription to send notifications to a Kafka topic. You can configure a custom topic name if needed, or allow a topic name to be generated automatically. Custom topic names always begin with ns-eg-tel-. For example, if you enter my-subscription in the custom notification parameter, the topic will be ns-eg-tel-my-subscription.

If a subscription with a custom topic name is deleted, the topic name can be used again by a new subscription.

Note: Custom topic names can only be configured when the subscription is created, and cannot be edited.

Once a Kafka topic has been associated with a telemetry subscription, it remains associated until the telemetry subscription is deleted. If the subscription is disabled, the topic continues to appear in the NSP UI. However, to preserve resources, if the subscription has been disabled for more than five min, the notifications and information related to the topic are deleted from Kafka.

Telemetry subscriptions are disabled automatically by the system under a number of scenarios, including YANG file deletion, Kafka being unavailable or another issue that results in loss of NBI topics.

If a topic is deleted while a consumer, such as an OSS, is consuming it, an exception is thrown. To avoid this error, ensure that no consumers are monitoring the topic before disabling or deleting the subscription.