Flow-aware transport pseudowire for BGP L2VPN and BGP VPLS

The flow-aware transport (FAT) label that is supported for BGP-signaled pseudowires such as L2VPN and VPLS is configured only on the label edge routers (LERs). This causes the transit routers or label-switching routers(LSRs) to perform load balancing of MPLS packets across equal-cost multipath (ECMP) paths or link aggregation groups (LAGs) without the need for deep packet inspection of the payload. The FAT flow label can be used for LDP-signaled forwarding equivalence class (FEC 128 and FEC 129) pseudowires for VPWS and VPLS pseudowires.