  Despite the high throughput and low complexity achieved by input scheduling
based on Birkhoff-von-Neumann (BvN) decomposition; the performance of the BvN
switch becomes less predictable when the input traffic is bursty. In this
paper, we propose a deflection-compensated BvN (D-BvN) switch architecture to
enhance the quasi-static scheduling based on BvN decomposition. The D-BvN
switches provide capacity guarantee for virtual circuits (VCs) and deflect
bursty traffic when overflow occurs. The deflection scheme is devised to offset
the excessive buffer requirement of each VC when input traffic is bursty. The
design of our conditional deflection mechanism is based on the fact that it is
unlikely that the traffic input to VCs is all bursty at the same time; most
likely some starving VCs have spare capacities when some other VCs are in the
overflow state. The proposed algorithm makes full use of the spare capacities
of those starving VCs to deflect the overflow traffic to other inputs and
provide bandwidth for the deflected traffic to re-access the desired VC. Our
analysis and simulation show that this deflection-compensated mechanism can
support BvN switches to achieve close to 100% throughput of offered load even
with bursty input traffic, and reduces the average end-to-end delay and delay
jitter. Also, our result indicates that the packet out-of-sequence probability
due to deflection of overflow traffic is negligible, thus only a small
re-sequencing buffer is needed at each output port.
