a packet is a package of data, and from what I know online apps have unique 'shapes' of their packets..this enables ISPs to control what's going through their pipes which is called 'packet shaping' and in a nutshell describes their ability to block p2p traffic...

as noted, the trace I did was very 'good' and 'discrete' (i.e. had no unknown hops being blocked by a firewall or somesuch), BUT..there was the above hop that was slowed down markedly..and that makes me wonder..