This attribute specifies the Transient Buffer Exposure (TBE) for this
connection. TBE is the negotiated number of cells that the network
would like to limit the source to send during start-up periods, before
the first Resource Management (RM) cell returns.
TBE divided by fixedRoundTripTime determines an upper bound
for the operational value of initialCellRate, the rate at which a
source should send initially and after an idle period.
TBE divided by maxCellsPerRmCell specifies the operational value
of forwardRmCellLimit, the limit of the number of forward
Resource Management (RM) cells which may be sent in the
absence of received backward RM cells.
This attribute is ignored under all conditions where the operational
attribute abrConnectionType is set to erSwitch.