Systems and methods include, at a first Border Gateway Protocol (BGP) speaker node which interconnects two autonomous systems, receiving an advertisement containing available bandwidth on one or more links between the two autonomous systems from a second BGP speaker node; and, for a BGP best path calculation between the two autonomous systems at the first BGP speaker node, selecting a link of the one or more links based on the available bandwidth on the link from the advertisement. At the first BGP speaker node, the systems and methods can further include determining bandwidth on the one or more links; and transmitting an updated advertisement based on the determined bandwidth. The bandwidth can be determined based on a configurable sampling interval. The transmitted update can be provided if the determined bandwidth has changed from a previous value by more than a configurable threshold.