  Current practice of shaping subscriber traffic based on token bucket by
Internet service provider (ISP) allows short-term fluctuations in its shaped
rate and thereby enables a subscriber to transmit traffic at a higher rate than
a negotiated long-term average. The traffic shaping, however, results in
significant waste of network resources, especially when there are only a few
active subscribers, because it cannot allocate excess bandwidth to active
subscribers in the long term. In this letter we investigate the long-term
aspect of resource sharing in ISP traffic control for shared access networks.
We discuss major requirements for the excess bandwidth allocation in shared
access networks and propose ISP traffic control schemes based on core-stateless
fair queueing (CSFQ) and token bucket meters. Simulation results demonstrate
that the proposed schemes allocate excess bandwidth among active subscribers in
a fair and efficient way, while not compromising the service contracts
specified by token bucket for conformant subscribers.
