Linux traffic shaping and bandwidth management

There are several types of traffic on any network and not all have the same characteristics, the same needs. So, what types of traffic do we have? There is interactive traffic (ssh, telnet, ftp-control, maybe irc and muds.. everything where it is important to have little delay.. web surfing is also interactive) and there is bulk traffic (ftp-data, p2p, downloading from the web). You can also treat "really-minimal-delay-traffic" differently (interactive might be better regarded to as "human-interactive") - like dns requests and tcp ACK packets, maybe some ICMP types.