This sets the imputed bandwidth, in bytes per second, attributed to this multicast group for the purpose of enforcing gponOnuIgmpGlobalBW's max-bandwidth limit; a value of 0 (the recommended default) effectively exempts this group from that limit, per ITU-T G.988 9.3.27. Admins set it so the bandwidth accounting used to decide whether to honor a join request reflects this group's actual stream size. For example, setting this to an HD channel's real bitrate ensures the per-subscriber bandwidth cap accurately accounts for that channel when deciding whether to admit another join.