[CAUSE] The vRtrLdpNgSessionStateChange notification is generated when the LDP Overload Notification message is sent to or received from the peer vRtrLdpNgPeerLdpId for the combination of vRtrLdpNgSessOverloadFecType and vRtrLdpNgSessOvldFecTypeSubTyp while vRtrLdpNgSessState remains 'operational'. [EFFECT] Once the Local LSR has sent the LDP Overload Notification message to the peer vRtrLdpNgPeerLdpId for fec and sub type fec indicated by vRtrLdpNgSessOverloadFecType and vRtrLdpNgSessOvldFecTypeSubTyp and vRtrLdpNgSessOverloadState has the value of 'true', then new Label Mapping Messages received for this peer for the given combination of fec and sub type fec is returned with a Label Release Message. If the Local LSR has received an LDP Overload Notification message from the peer vRtrLdpNgPeerLdpId for fec and sub type fec indicated by vRtrLdpNgSessOverloadFecType and vRtrLdpNgSessOvldFecTypeSubTyp and vRtrLdpNgSessOverloadState has the value of 'true', no new Label Mapping Message for the given combination of fec and sub type fec will be sent to this peer. If the Local LSR has received an LDP Overload Notification message from the peer vRtrLdpNgPeerLdpId for fec and sub type fec indicated by vRtrLdpNgSessOverloadFecType and vRtrLdpNgSessOvldFecTypeSubTyp and vRtrLdpNgSessOverloadState has the value of 'false', then the Local LSR will send all pending and any new Label Mapping Message for the given combination of fec and sub type fec to this peer. [RECOVERY] In case the Local LSR sent the LDP Overload Notification message to the peer vRtrLdpNgPeerLdpId and vRtrLdpNgSessOverloadState has the value of 'true' for fec and sub type fec indicated by vRtrLdpNgSessOverloadFecType and vRtrLdpNgSessOvldFecTypeSubTyp, then appropriate LDP configuration changes may be required on the Local and/or Remote LSR. Once the Local LSR is not overloaded anymore, an LDP Overload Notification message is sent to the peer vRtrLdpNgPeerLdpId and vRtrLdpNgSessOverloadState has the value of 'false' for given fec and sub type fec.