For flows that may take a significant fraction of the network (i.e. are ``special'') , we need a more dynamic way of establishing these classifications. In the short term, this applies to any multimedia calls since the Internet is largely under-provisioned at time of writing.
The Resource Reservation Protocol, RSVP is being standardised for just this purpose. It provides flow identification and classification. Hosts and applications are modified to speak RSVP client language, and routers speak RSVP.
Since most traffic requiring reservations is delivered to groups (e.g. TV), it is natural for the receiver to make the request for a reservation for a flow. This has the added advantage that different receivers can make heterogeneous requests for capacity from the same source. Again the routers conspire to deliver the right flows to the right locations. RSVP accommodates the wild-carding noted above. This is discussed in more detail in chapter 2.