MDT Subscription

Model Driven Telemetry (MDT) is a push-based streaming telemetry mechanism that provides real-time, structured data from network devices using YANG data models and protocols such as gRPC, enabling continuous monitoring and analytics. It supports both periodic data collection and event-driven notifications with configurable update policies, allowing network operators to receive precise operational data including interface statistics, routing table changes, and system health metrics. MDT subscriptions eliminate the need for polling-based monitoring by delivering high-frequency, low-latency data streams that can be consumed by network management systems, analytics platforms, and automated monitoring tools.

By providing real-time, push-based streaming telemetry, MDT subscriptions enable continuous monitoring and analytics without traditional polling.

Key Components:

• Subscription ID (id): Unique identifier for the telemetry subscription.

• Stream Type (stream): Specifies the telemetry stream type (e.g., yang-push, yang-notif-native).

• Encoding (encoding): Sets the encoding format for telemetry data (e.g., encode-kvgpb, encode-json).

• Source VRF (source_vrf): Specifies the source VRF for the telemetry stream.

• Source IP Address (source_ip): Sets the source IP address for the telemetry stream.

• Update Policy (update_policy_on_change, update_policy_periodic): Configures the update policy (on-change or periodic interval).

• Filter XPath (filter_xpath): Applies an XPath filter for specific data points.

• Receivers (receivers): Defines receiver details (IP address, port, protocol).

Key Parameters Briefly Explained:

• id: Subscription identifier.
• stream: Telemetry stream type.
• encoding: Data encoding format.
• source_vrf: Source VRF.
• source_ip: Source IP address.
• update_policy_on_change, update_policy_periodic: Update policy settings.
• filter_xpath: XPath filter for data selection.
• receivers: Telemetry data receivers.

You can use these MDT Subscription parameters to configure real-time streaming telemetry from your network devices. Customize the subscription ID, stream type, encoding, data filters, and receiver details to fit your monitoring and analytics requirements. Adjusting these parameters lets you tailor the type and frequency of operational data streamed from the device.

The following configuration describes how to set up MDT subscriptions on a Cisco IOS-XE device, including event-driven and periodic subscriptions, stream types, encoding, source information, XPath filters, and receiver details.

telemetry ietf subscription 202
 stream yang-notif-native
 encoding encode-kvgpb
 source-vrf Mgmt-test
 source-address 1.2.9.10
 update-policy on-change
 filter xpath /ios-events-ios-xe-oper:ospf-neighbor-state-change
 receiver ip 9.8.3.2 57600 protocol grpc-tcp
!
telemetry ietf subscription 203
 stream yang-push
 encoding encode-json
 update-policy periodic 30000
 filter xpath /interfaces-ios-xe-oper:interfaces/interface
 receiver ip 192.168.1.100 50051 protocol grpc-tcp

The following YAML code defines MDT subscriptions on an IOS-XE device, including subscription IDs, stream types, encoding, source VRF/IP, update policies, XPath filters, and receiver details.

iosxe:
  devices:
    - name: Device1
      configuration:
        mdt_subscriptions:
          - id: 202
            stream: yang-notif-native
            encoding: encode-kvgpb
            source_vrf: Mgmt-test
            source_ip: 1.2.9.10
            update_policy_on_change: true
            filter_xpath: /ios-events-ios-xe-oper:ospf-neighbor-state-change
            receivers:
              - ip: 9.8.3.2
                port: 57600
                protocol: grpc-tcp
          - id: 203
            stream: yang-push
            encoding: encode-json
            update_policy_periodic: 30000
            filter_xpath: /interfaces-ios-xe-oper:interfaces/interface
            receivers:
              - ip: 192.168.1.100
                port: 50051
                protocol: grpc-tcp