  Realizing that it is inherently difficult to precisely match the sending
rates at the endhost with the available capacity on dynamic cellular links, we
build a system, Octopus, that sends real-time data streams over cellular
networks using an imprecise controller (that errs on the side of
over-estimating network capacity), and then drops appropriate packets in the
cellular network buffers to match the actual capacity. We design parameterized
primitives for implementing the packet dropping logic, that the applications at
the endhost can configure differently to express different content adaptation
policies. Octopus transport encodes the app-specified parameters in packet
header fields, which the routers parse to execute the desired dropping
behavior. Our evaluation shows how real-time applications involving standard
and volumetric videos can be designed to exploit Octopus, and achieve 1.5-50
times better performance than state-of-the-art schemes.
