  The multi-link operation (MLO) is a new feature proposed to be part of the
IEEE 802.11be Extremely High Throughput (EHT) amendment. Through MLO, access
points and stations will be provided with the capabilities to transmit and
receive data from the same traffic flow over multiple radio interfaces.
However, the question on how traffic flows should be distributed over the
different interfaces to maximize the WLAN performance is still unresolved. To
that end, we evaluate in this article different traffic allocation policies,
under a wide variety of scenarios and traffic loads, in order to shed some
light on that question. The obtained results confirm that congestion-aware
policies outperform static ones. However, and more importantly, the results
also reveal that traffic flows become highly vulnerable to the activity of
neighboring networks when they are distributed across multiple links. As a
result, the best performance is obtained when a new arriving flow is simply
assigned entirely to the emptiest interface.
