BGPrunsoverareliabletransport().Thiseliminatestheneedtoimplementexplicitupdatefragmentation,retransmission,acknowledgement,and().AnyauthenticationschemeusedbythetransportprotocolmaybeusedinadditiontoBGP'sown()mechanisms.TheerrornotificationmechanismusedinBGP()thatthetransportprotocolsupportsa“graceful”close,i.e.,thatalloutstandingdatawillbedelivered(请作答此空)theconnectionisclosed.
A.after
B.before
C.earlier
D.concurrently
正确答案是B