  In-band Network Telemetry (INT) and sketching algorithms are two promising
directions for measuring network traffics in real time. To combine sketch with
INT and preserve their advantages, a representative approach is to use INT to
send a switch sketch in small pieces (called sketchlets) to end-host for
reconstructing an identical sketch. However, in this paper, we reveal that when
naively selecting buckets to sketchlets, the end-host reconstructed sketch is
inaccurate. To overcome this problem, we present DUNE, an innovative sketch-INT
network measurement system. DUNE incorporates two key innovations: First, we
design a novel scatter sketchlet that is more efficient in transferring
measurement data by allowing a switch to select individual buckets to add to
sketchlets; Second, we propose lightweight data structures for tracing
"freshness" of the sketch buckets, and present algorithms for smartly selecting
buckets that contain valuable measurement data to send to end-host. We
theoretically prove the effectiveness of our proposed methods, and implement a
prototype on commodity programmable switch. The results of extensive
experiments driven by real-world traffics on DUNE suggest that our proposed
system can substantially improve the measurement accuracy at a trivial cost.
