P. sterberg and T. Zhang (Sweden)
Multicast, Fairness, Bandwidth Allocation, Layered
As multicast is slowly gaining in support, the concept of
multicast fairness is starting to attract some attention.
Should multicast flows be favored at the expense of
unicast flows, and if so to what extent? Allocating link
bandwidth in proportion to the logarithm of the number of
receivers of a flow has been proposed. That kind of
policies favors multicast flows, without totally starving
unicast flows. A problem of maintaining such policies
emerges if layered multicast flows are introduced, since
each layer is transmitted to a separate multicast IP address
and will therefore be treated as an individual flow.
Layered multicast flows will consequently be allocated
too much bandwidth. In this paper, a logarithmic
bandwidth-allocation policy that copes with layered
multicast is proposed and evaluated through simulations.
The results confirm that the proposal meets the
expectations by preserving the intended fairness
properties in scenarios with layered multicast traffic.