Multicast Fairness-Independent and Fine-Grained AQM Mechanism for Multicast Flows

Fethi Filali

INRIA Sophia Antipolis


The efficient support of the multicast communication by existing network infrastructure and protocols releaves many open issues, including multicast congestion control, multicast routing, inter- and intra- multicast fairness.

In this talk, we propose a new active queue management mechanism called MFQ (Multicast Fair Queueing) for multicast flows. MFQ is independent of the inter-multicast fairness policy and it interacts with a multicast bandwidth allocation module that can implement either a multicast fairness policy or a multicast pricing model and tries using a single FIFO queue to achieve the expected allocation. The multicast fairness is assumed to be a function of the number of competing multicast groups, the number of flows per group, and the number of receivers per flow. MFQ uses, Multicast Allocation Layer (MAL), a novel notion that permits to guarantee a fine-grained packet queueing/dropping.

We perform simulations to evaluate the performance of MFQ for different bandwidth allocation schemes. Results obtained suggest that, on the one hand MFQ achieves the expected allocation for both responsive and non-responsive multicast flows and on the other hand it is able to adapt to situations where the competing flows have heterogenous rate. We validate our findings by analysing a multiple-bottleneck scenario, and comparing with the expected results. In particular, we show that MFQ appears to converge very fast and easily adapt itself to the change on the number of receivers per flow and the number of active multicast flows.

[Fethi Filali]
[INRIA Sophia Antipolis]