Summary

The transport infrastructure spans a large number of networks and traffic that must be managed at two levels. The network managers must consider how they will measure and manage the network characteristics of bandwidth, availability, packet loss, latency, and jitter.

Flows within a single organization's domain are managed using specialized technologies that can tag data packets for special handling and can make reservations for that special handling.

Rate control and queuing can be used at key network points to manage bandwidth for all the traffic streams passing through those points. Some organizations don't use flow management technologies; they simply over-provision massively, hoping that there won't be severe congestion problems.

Flows across management domain boundaries are an ongoing challenge. Attaining flow-through QoS and delivering consistent end-to-end quality independent of the set of ISPs used is the goal. The technical means are becoming available with the introduction of MPLS and route control, although the administrative burdens are still high.