Returns the input physical link number of an adjacent switch, to which
this switch in question is connected by an output physical link specified
by the parameter 'linkNo'
Returns the message size in flits, which may be either fixed or
exponential random number computed from the average message length(in
bytes) and flit length (in bits).
Invoked by Network.setAdjacentFatSwitch() and
Network.setAdjacentExFatSwitch() to find out the first parent switch
exists in the upper level by using current switch’s level and index in
level values.