Overview of the Junos Telemetry Interface
As the number of objects on the network and the metrics they generate have grown, the traditional models, such as SNMP, used to gather operational statistics for monitoring the health of a network, have imposed limits on network element scale and efficiency. The so-called pull model used by SNMP and the CLI, which requires additional processing to periodically poll the network element, directly limits scaling.
The Junos Telemetry Interface (JTI) overcomes these limits by relying on a so-called push model to deliver data asynchronously, which eliminates polling. A request to send data is sent once by a management station to stream periodic updates. As a result, JTI is highly scalable and can support the monitoring of thousands of objects in a network.
Telemetry Sensors and Data Models
The Junos Telemetry Interface enables you to provision sensors to collect and export data for various system resources, such as physical interfaces and firewall filters. Two data models, each of which uses a different mode of transport, are supported:
An open and extensible data model defined by Juniper Networks. Data is generated as Google protocol buffers (gpb) structured messages. The files that define each
.proto
message are published on the Juniper Networks web site. Native sensors export data close to the source, such as the line card or network processing unit (NPU), using the User Datagram Protocol (UDP). Because this model features a distributed architecture, it scales easily.-
The OpenConfig data model generates data as gpb messages in a universal key/value format. OpenConfig supports the YANG data models. gRPC remote procedure calls (gRPC) are used to provision sensors and to subscribe to and receive telemetry data. gRPC is based on TCP and supports TLS, which enables data transmission security over TCP. TLS is used to establish secure and reliable encrypted communication channels for data transmission. Starting in Junos OS Release 18.2R1, OpenConfig-based routing engine (RE) sensors can stream data as gpb-structured messages over UDP.
Change History Table
Feature support is determined by the platform and release you are using. Use Feature Explorer to determine if a feature is supported on your platform.