CREATE_SESSION4_FLAG_CONN_BACK_CHAN
bdrpc = ap->cs_aotw.csa_flags & CREATE_SESSION4_FLAG_CONN_BACK_CHAN;
sp->sn_csflags |= CREATE_SESSION4_FLAG_CONN_BACK_CHAN;
sp->sn_csflags &= ~CREATE_SESSION4_FLAG_CONN_BACK_CHAN;