Index: zaptel-base.c
===================================================================
--- zaptel-base.c	(révision 41)
+++ zaptel-base.c	(révision 42)
@@ -2127,7 +2127,9 @@
 	if (chan->span->flags & ZT_FLAG_RBS) {
 		if (chan->sig == ZT_SIG_CAS) {
 			zt_cas_setbits(chan, chan->idlebits);
-		} else if ((chan->sig == ZT_SIG_FXOKS) && (chan->txstate != ZT_TXSTATE_ONHOOK)) {
+		} else if ((chan->sig == ZT_SIG_FXOKS) && (chan->txstate != ZT_TXSTATE_ONHOOK)
+			/* if other party is already on-hook we shouldn't do any battery drop */
+			&& !((chan->rxhooksig == ZT_RXSIG_ONHOOK) && (chan->itimer <= 0))) {
 			/* Do RBS signalling on the channel's behalf */
 			zt_rbs_sethook(chan, ZT_TXSIG_KEWL, ZT_TXSTATE_KEWL, ZT_KEWLTIME);
 		} else