This attribute is applicable and is displayed only for connections for
which the operational Tm abrConnectionType is displayed as
sourceDest or virtualSourceDest.
This attribute indicates the Fixed Round-Trip Time (FRTT)
parameter for this connection. FRTT is the sum of the fixed and
propagation delays from the source to a destination and back.
For nailed-up connections, this attribute is determined by the
provisioned value of the fixedRoundTripTime attribute. For
signalled connections, it is indicated in the ABR Setup Parameters
Information Element.