* <tt>limiter(A)_UP, private(A)_UP, backbone, private(B)_DOWN, limiter(B)_DOWN.</tt>
* link_UP and link_DOWN usually share the exact same characteristics, but their
* performance are not shared, to model the fact that TCP links are full-duplex.
* <tt>limiter(A)_UP, private(A)_UP, backbone, private(B)_DOWN, limiter(B)_DOWN.</tt>
* link_UP and link_DOWN usually share the exact same characteristics, but their
* performance are not shared, to model the fact that TCP links are full-duplex.