(M2PA) Question about Busy Procedure

Hello All,

RFC4165 implies that M2PA should mark remote congestion condition and
stop
transmitting non-empty user data messages upon reception of LS Busy,
whether
or not its RTB contains a message (timer T7 is running). 

Shouldn't the ANSI variant M2PA behave like T1.111.3 (Figure 13, sheet
4) MTP2
and ignore received LS Busy (SIB) when its RTB is empty? If not, and
M2PA
marks remote congestion condition when RTB is empty and does not start
T6, how long, in the absence of received LS Busy Ended, should it
continue
to buffer MSUs received from MTP3 for transmission?

RFC4165 states that M2PA must not acknowledge a received user data
message
that triggers (implementation-dependent) local congestion onset. Is this
requirement intended to force the RTB of the peer to always be non-empty

upon reception of LS Busy?

Regards,

Jeff