A read-only value that identifies the operational state
of the Multi-Point MAC Control sublayer as defined in
[802.3ah] clause 64. When this attribute has the
enumeration unregistered(1) the interface may be used
for registering a link partner. When this attribute has
the enumeration registering(2) the interface is in the
process of registering a link-partner. When this
attribute has the enumeration registered(3) the
interface has an established link-partner.
This attribute is relevant for an OLT and an ONU. For
the OLT it provides an indication per LLID.