Inter-Domain Traffic Engineering using the Origin Preference Attribute

Abstract

Inter-domain Traffic Engineering (TE) is an important aspect of network operation both technically and economically. Outbound Traffic Engineering is less problematic as routers under the control of the network operator are responsible for the way traffic leaves the network. The inbound direction is considerably harder as the way traffic enters a network is based on routing decisions in other networks. There are very few mechanisms available today that facilitate inter-domain inbound traffic engineering, such as prefix deaggregation (i.e., advertise more specific prefixes), AS path prepending and systems based on BGP communities. These mechanisms have severe drawbacks such as exacerbating the increase of the size of global routing table or providing only coarse-grained control. In this chapter, an alternative mechanism is described and evaluated. The proposed solution does not increase the size of the global routing table, is easy to configure through a simple numeric value and provides a finer-grained control compared to currently used mechanisms that also do not add additional prefixes to the global routing table.