The router supports two modes of multiplexing RX/TX control for LACP: coupled and independent.
In coupled mode (default), both RX and TX are enabled or disabled at the same time whenever a port is added or removed from a LAG group.
In independent mode, RX is first enabled when a link state is UP. LACP sends an indication to the far-end that it is ready to receive traffic. Upon the reception of this indication, the far-end system can enable TX. Therefore, in independent RX/TX control, LACP adds a link into a LAG only when it detects that the other end is ready to receive traffic. This minimizes traffic loss that may occur in coupled mode if a port is added into a LAG before notifying the far-end system or before the far-end system is ready to receive traffic. Similarly, on link removals from LAG, LACP turns off the distributing and collecting bit and informs the far-end about the state change. This allows the far-end side to stop sending traffic as soon as possible.
Independent control provides for lossless operation for unicast traffic in most scenarios when adding new members to a LAG or when removing members from a LAG. It also reduces loss for multicast and broadcast traffic.
Note that independent and coupled mode are interoperable (connected systems can have either mode set).
Independent and coupled modes are supported when using PXC ports, however, independent mode is recommended as it provides significant performance improvements.