This attribute specifies the default value for end-to-end loopback
insertion for all connections under this interface. End-to-end
loopback insertion is not possible if the connectionPointType
attribute of the Vcc or Vpc component is connectingPoint or
segmentEndPoint. End-to-end loopback insertion is possible if the
connectionPointType attribute of the Vcc or Vpc component is
connectionEndPoint. End-to-end loopback insertion is always
possible on a Vpt component.