Specifically, like in an IPv4 network, BIER can get the job done more than L2 hyperlinks right or more than tunnels. Zheng Zhang, Bo Wu, Zhaohui Zhang, IJsbrand Wijnands, Yisong Liu, Hooman Bidgoli, 2022-07-03, This document defines a BIER proxy functionality to aid a solitary BIER sub-area around several underlay routing protocol areas (Autonomous Systems or IGP parts).