IJCSNS International Journal of Computer Science and Network Security, VOL.6 No.2B, February 2006
Summary -- Bandwidth Contention in VDSL network
the demand of
consumption exceeds the network capacity per se,
causing lower throughputs and higher traversal time
(delays). If the bandwidth contention cannot be ease
transported by the network may not meet their
quality-of-services (QoS). An existing method may
simply reduce incoming traffic rate to boggle down
their in-flow. Another method may try to believe in the
end-to-end protocols for the recovery of lost packets.
However, in this paper, a conservative method, called
backpressure scheme, is proposed in order to ensure
that no frames will be dropped nor discarded during
the transmission, even if the contention arises.
Backpressure scheme is introduced then will be
evaluated by comparing versus traditional policing
mechanisms, namely, Leaky Bucket(LB), Jumping
Window(JW) and Triggered Jumping Window(TJW)
versus other backoff schemes, namely,
pseudorandom backoff scheme (PB), random backoff
scheme (RB) and exponential backoff scheme (EB).
Simulation results show that over VDSL network, the
backpressure scheme outperforms by improving
throughputs while on the other hands, reducing
Key words -- Policing mechanisms, backoff schemes
and backpressure scheme.
In most networks, if a network device receives
more frames than it can forward, then the device
buffers the backlog. However, once the buffer is filled
up then the device begins to discard frames. This may
retransmissions will normally occupy and contend
throughput. An alternative approach is
to perform hop-counts in flow control, or to conserve
Manuscript received June 2, 2005 and revised January 7, 2006.
Mr.Lekcharoen is with the Faculty of