diff --git a/src/router/audio.c b/src/router/audio.c
index a4a83a7..e997759 100644
--- a/src/router/audio.c
+++ b/src/router/audio.c
@@ -115,7 +115,7 @@ static void gain_samples(sample_t *samples, int length, double gain)
 		*samples++ *= level;
 }
 
-static void send_terminator(call_relation_t *relation, sample_t *samples, int len)
+static void send_terminator(call_relation_t *relation, sample_t *samples, int len, uint8_t marker)
 {
 	int16_t spl[len];
 
@@ -123,10 +123,10 @@ static void send_terminator(call_relation_t *relation, sample_t *samples, int le
 	samples_to_int16_speech(spl, samples, len);
 
 	/* encode and send via RTP */
-	osmo_cc_rtp_send(relation->codec, (uint8_t *)spl, len * sizeof(*spl), 1, len);
+	osmo_cc_rtp_send(relation->codec, (uint8_t *)spl, len * sizeof(*spl), marker, 1, len);
 }
 
-void receive_originator(struct osmo_cc_session_codec *codec, uint16_t sequence, uint32_t timestamp, uint32_t ssrc, uint8_t *data, int len)
+void receive_originator(struct osmo_cc_session_codec *codec, uint8_t marker, uint16_t sequence, uint32_t timestamp, uint32_t ssrc, uint8_t *data, int len)
 {
 	call_relation_t *relation = codec->media->session->priv;
 	call_t *call = relation->call;
@@ -135,7 +135,7 @@ void receive_originator(struct osmo_cc_session_codec *codec, uint16_t sequence,
 
 	if (codec->decoder == decode_te) {
 		struct telephone_event *te = (struct telephone_event *)data;
-		telephone_event(relation, te);
+		telephone_event(relation, marker, te);
 		return;
 	}
 
@@ -154,7 +154,7 @@ void receive_originator(struct osmo_cc_session_codec *codec, uint16_t sequence,
 	jitter_save(&call->orig_dejitter, samples, len, 1, sequence, timestamp, ssrc);
 }
 
-static void send_originator(call_relation_t *relation, sample_t *samples, int len)
+static void send_originator(call_relation_t *relation, sample_t *samples, int len, uint8_t marker)
 {
 	int16_t spl[len];
 	call_t *call = relation->call;
@@ -166,10 +166,10 @@ static void send_originator(call_relation_t *relation, sample_t *samples, int le
 	/* convert samples to int16 */
 	samples_to_int16_speech(spl, samples, len);
 
-	osmo_cc_rtp_send(relation->codec, (uint8_t *)spl, len * sizeof(*spl), 1, len);
+	osmo_cc_rtp_send(relation->codec, (uint8_t *)spl, len * sizeof(*spl), marker, 1, len);
 }
 
-void receive_terminator(struct osmo_cc_session_codec *codec, uint16_t sequence, uint32_t timestamp, uint32_t ssrc, uint8_t *data, int len)
+void receive_terminator(struct osmo_cc_session_codec *codec, uint8_t __attribute__((unused)) marker, uint16_t sequence, uint32_t timestamp, uint32_t ssrc, uint8_t *data, int len)
 {
 	call_relation_t *relation = codec->media->session->priv;
 	call_t *call = relation->call;
@@ -267,10 +267,10 @@ void call_clock(int len)
 		/* record */
 		if (call->rec.fp)
 			wave_write(&call->rec, samples, len);
-		/* forward audio */
-		send_originator(relation, sbuffer2, len);
+		/* forward audio (no marker set) */
+		send_originator(relation, sbuffer2, len, 0);
 		if (!call->forking && relation->next)
-			send_terminator(relation->next, sbuffer, len);
+			send_terminator(relation->next, sbuffer, len, 0);
 	}
 }
 
diff --git a/src/router/audio.h b/src/router/audio.h
index 71b4df2..356418d 100644
--- a/src/router/audio.h
+++ b/src/router/audio.h
@@ -1,6 +1,6 @@
 
-void receive_originator(struct osmo_cc_session_codec *codec, uint16_t sequence_number, uint32_t timestamp, uint32_t ssrc, uint8_t *data, int len);
-void receive_terminator(struct osmo_cc_session_codec *codec, uint16_t sequence_number, uint32_t timestamp, uint32_t ssrc, uint8_t *data, int len);
+void receive_originator(struct osmo_cc_session_codec *codec, uint8_t marker, uint16_t sequence_number, uint32_t timestamp, uint32_t ssrc, uint8_t *data, int len);
+void receive_terminator(struct osmo_cc_session_codec *codec, uint8_t marker, uint16_t sequence_number, uint32_t timestamp, uint32_t ssrc, uint8_t *data, int len);
 void call_media_handle(void);
 void call_clock(int len);
 void encode_l16(uint8_t *src_data, int src_len, uint8_t **dst_data, int *dst_len);
diff --git a/src/router/call.c b/src/router/call.c
index 49aed0c..784751f 100644
--- a/src/router/call.c
+++ b/src/router/call.c
@@ -2055,19 +2055,29 @@ void routing_close(routing_t *routing)
 	call_destroy(call);
 }
 
-void telephone_event(call_relation_t *relation, struct telephone_event *te)
+void telephone_event(call_relation_t *relation, uint8_t marker, struct telephone_event *te)
 {
 	char digit_string[7] = "dtmf x";
 
 	if (te->event < 16) {
-		if (!relation->te_started && !te->e && te->volume <= 36) {
-			PDEBUG(DROUTER, DEBUG_INFO, "Received start of Telephone-Event '%d'\n", te->event);
+		if (marker && te->volume <= 36) {
+			if (!te->e) {
+				PDEBUG(DROUTER, DEBUG_INFO, "Received start of Telephone-Event '%d' duration=%d ms (marker set)\n", te->event, te->duration / 8);
+				relation->te_started = 1;
+			} else
+				PDEBUG(DROUTER, DEBUG_INFO, "Received start and end of Telephone-Event '%d' duration=%d ms (marker set)\n", te->event, te->duration / 8);
+			digit_string[5] = "0123456789*#ABCD"[te->event];
+		} else if (!relation->te_started && !te->e && te->volume <= 36) {
+			PDEBUG(DROUTER, DEBUG_INFO, "Received start of Telephone-Event '%d' duration=%d ms (marker not set, this is wrong!)\n", te->event, te->duration / 8);
 			relation->te_started = 1;
 			digit_string[5] = "0123456789*#ABCD"[te->event];
-		}
-		if (relation->te_started && te->e) {
+		} else if (relation->te_started && !te->e && te->volume <= 36) {
+			PDEBUG(DROUTER, DEBUG_DEBUG, "Received subsequent Telephone-Event '%d' duration=%d ms\n", te->event, te->duration / 8);
+		} else if (relation->te_started && te->e) {
 			PDEBUG(DROUTER, DEBUG_INFO, "Received end of Telephone-Event '%d'\n", te->event);
 			relation->te_started = 0;
+		} else if (!relation->te_started && te->e) {
+			PDEBUG(DROUTER, DEBUG_DEBUG, "Received subsequent end of Telephone-Event '%d'\n", te->event);
 		}
 	} else
 		PDEBUG(DROUTER, DEBUG_INFO, "Received unsupported Telephone-Event '%d'\n", te->event);
diff --git a/src/router/call.h b/src/router/call.h
index 3be0384..e248da1 100644
--- a/src/router/call.h
+++ b/src/router/call.h
@@ -96,7 +96,7 @@ int call_init(osmo_cc_endpoint_t *cc_ep1, osmo_cc_endpoint_t *cc_ep2, const char
 void call_exit(void);
 int call_handle(void);
 void cc_message(osmo_cc_endpoint_t *ep, uint32_t callref, osmo_cc_msg_t *msg);
-void telephone_event(call_relation_t *relation, struct telephone_event *te);
+void telephone_event(call_relation_t *relation, uint8_t marker, struct telephone_event *te);
 
 void routing_help(void);