It enables an ISP to maximise operational efficiency and minimise operational costs. In so doing, it can offer more options, lower costs, and provide better service to its customers. This approach is becoming ever more valuable as ISP networks grow larger and as customer demands become greater. IGP extensions can contribute to network congestion because bandwidth availability and traffic characteristics are not taken into account when forwarding tables are built. Traffic engineering resolves this issue by providing ISPs with precise control over traffic flows within their routed domains, thereby letting them redirect traffic away from the shortest path and onto a potentially less congested route.
Traffic engineering has several capabilities.
Firstly, it can route primary paths around congestion in the network. It provides precise control over how traffic is re-routed when a primary path fails. It provides efficient use of available aggregate bandwidth and long-haul fibre by optimally using all segments. It also enhances traffic performance by minimising packet loss, through minimising prolonged periods of congestion, and maximising throughput. Traditional routed cores have limited aggregate bandwidth and packet-processing capabilities.