Passive aggressive measurement with MGRP

Abstract

We present the Measurement Manager Protocol (MGRP), an in-kernel service that schedules and transmits probes on behalf of active measurement tools. Unlike prior measurement services, MGRP transparently piggybacks application packets inside the often significant amounts of empty padding contained in typical probes. Using MGRP thus combines the modularity, flexibility, and accuracy of standalone active measurement tools with the lower overhead of passive measurement techniques. Microbenchmark experiments show that the resulting bandwidth savings makes it possible to measure the network accurately, but faster and more aggressively than without piggybacking, and with few ill effects to piggybacked application or competing traffic. When using MGRP to schedule measurements on behalf of MediaNet, an overlay service that adaptively schedules media streams, we show MediaNet can achieve significantly higher streaming rates under the same network conditions.

Timing is Everything

“…But, for general TCP traffic, the minute modulation that minProbe causes does not affect the rate or TCP throughput. Similar results have been demonstrated in prior art MGRP [37]. One problem may occur when a TCP cwnd (congestion window) is small, e.g., when cwnd = 1.…”

“…Bandwidth estimation tools add traffic to the network path under measurement. This may adversely affect application traffic and measurement accuracy [37]. The amount of probe traffic is proportional to the rate of sampling and the number of concurrent measurement sessions.…”

“…Thus, by using application traffic implicitly as available bandwidth probes, we are able to remove all the traditional costs and overheads. A similar idea was proposed in MGRP [37], which has the same goal of lower overhead, but MGRP lacks highfidelity measurement capability.…”

“…Similar to MGRP [37], minProbe can use application traffic as probe packets. It has a programmable flow table that performs flow matching on pass-through traffic.…”

Low-Overhead End-to-End Performance Measurement for Next Generation Networks

“…Inline Measurement TCP (ImTCP) [27] and the Measurement Manager Protocol (MGRP) [28] operate at the TCP layer of the network stack and multiplex measurement and application traffic in order to infer network bandwidth. The former alters the TCP sending process to measure available bandwidth, whereas the latter uses measurement traffic to piggyback application data.…”