A switch or other network device may be configured as an ingress edge telemetry node in a telemetry domain. The ingress edge telemetry node may clone certain data units it processes, for example in response to certain telemetry triggers being met. The ingress edge telemetry node may further inject telemetry and/or other data into the cloned data unit. The cloned data unit continues along the same path as the original data unit until it reaches an egress edge telemetry node in the telemetry domain. The second node extracts the telemetry data from the cloned data unit and sends telemetry information based thereon to a telemetry collector, while the original data unit continues to its final destination. Nodes along the path between the first node and the second node may be configured as transit telemetry nodes that insert or otherwise update the telemetry data.