What is streaming network telemetry?
Streaming network telemetry is a real-time data collection service in which network devices, such as routers, switches and firewalls, continuously push data related to the network's health to a centralized location. In general, telemetry is the science of transmitting measurements from a remote source to a receiving station for storage and analysis.
Data streaming network telemetry is push-based, and data transmits automatically and continuously. The collected data supports the following capabilities:
How streaming network telemetry works
Data streams with protocols such as TCP, UDP, XML-RPC or gRPC in one of two ways. The first method, known as cadence-based telemetry, is when data sends information to a collector at regularly configured intervals. Cadence-based telemetry helps build historical baselines.
The second method, known as event-based telemetry, is when data sends when a specific event occurs, like when a critical link goes down or when the throughput on a link passes a specified maximum threshold.
Streaming network telemetry vs. SNMP
Prior to streaming network telemetry technologies, the Simple Network Monitoring Protocol (SNMP) was the standard method for collecting network telemetry information. However, SNMP uses a pull technology where an SNMP collector had to request telemetry information at regular intervals.
In typical enterprise networks, collectors are configured to request information between five and 30 minutes, so administrators end up with time gaps in the information gathered. Polling is also fairly resource intensive and does not scale well.
Streaming network telemetry, on the other hand, is a push technology. Instead of having the collector request data every few minutes, the network device streams health and interface data in near real time. Ultimately, it can provide more data point granularity with better performance when compared to SNMP.
Streaming network telemetry architecture
Network components capable of streaming network telemetry information can be configured to point to one or more data collectors. The communications sessions can be established by the network device subscribing to the collector, or the collector subscribing to the network device.
Streaming network telemetry can alert networking professionals about unusually sharp increases or decreases in traffic. The data collected by streaming telemetry is model-driven and ideal for using big data analytics to optimize traffic flow.
From an implementation standpoint, administrators have control over several aspects of the subscription and stream process. First, they choose who initiates the subscription conversation, either the network device or the collector.
Next, an administrator can selectively choose what information they want to collect. Standard data models such as IETF YANG, OpenConfig or vendor proprietary models help accomplish this process. Finally, admins choose the frequency that cadence-based data streams to a collector.
Editor's note: This article was republished in January 2023 to improve the reader experience.