Editing Network planning and design (section)

==Traffic engineering==
Compared to network engineering, which adds resources such as links, routers, and switches into the network, traffic engineering targets changing traffic paths on the existing network to alleviate traffic congestion or accommodate more traffic demand.

This technology is critical when the cost of network expansion is prohibitively high and the network load is not optimally balanced.  The first part provides financial motivation for traffic engineering while the second part grants the possibility of deploying this technology.