diff --git a/src/libosmocc/helper.c b/src/libosmocc/helper.c
index 6f2a718..c2e7bf3 100644
--- a/src/libosmocc/helper.c
+++ b/src/libosmocc/helper.c
@@ -54,6 +54,11 @@ osmo_cc_session_t *osmo_cc_helper_audio_offer(osmo_cc_session_config_t *conf, vo
 }
 
 const char *osmo_cc_helper_audio_accept(osmo_cc_session_config_t *conf, void *priv, struct osmo_cc_helper_audio_codecs *codecs, void (*receiver)(struct osmo_cc_session_codec *codec, uint8_t marker, uint16_t sequence_number, uint32_t timestamp, uint32_t ssrc, uint8_t *data, int len), osmo_cc_msg_t *msg, osmo_cc_session_t **session_p, osmo_cc_session_codec_t **codec_p, int force_our_codec)
+{
+	return osmo_cc_helper_audio_accept_te(conf, priv, codecs, receiver, msg, session_p, codec_p, NULL, force_our_codec);
+}
+
+const char *osmo_cc_helper_audio_accept_te(osmo_cc_session_config_t *conf, void *priv, struct osmo_cc_helper_audio_codecs *codecs, void (*receiver)(struct osmo_cc_session_codec *codec, uint8_t marker, uint16_t sequence_number, uint32_t timestamp, uint32_t ssrc, uint8_t *data, int len), osmo_cc_msg_t *msg, osmo_cc_session_t **session_p, osmo_cc_session_codec_t **codec_p, osmo_cc_session_codec_t **telephone_event_p, int force_our_codec)
 {
 	char offer_sdp[65536];
 	const char *accept_sdp;
@@ -136,6 +141,8 @@ const char *osmo_cc_helper_audio_accept(osmo_cc_session_config_t *conf, void *pr
 	osmo_cc_rtp_open(selected_media);
 	osmo_cc_rtp_connect(selected_media);
 	*codec_p = selected_codec;
+	if (telephone_event_p)
+		*telephone_event_p = telephone_event;
 
 	accept_sdp = osmo_cc_session_send_answer(*session_p);
 	if (!accept_sdp) {
@@ -148,9 +155,15 @@ const char *osmo_cc_helper_audio_accept(osmo_cc_session_config_t *conf, void *pr
 }
 
 int osmo_cc_helper_audio_negotiate(osmo_cc_msg_t *msg, osmo_cc_session_t **session_p, osmo_cc_session_codec_t **codec_p)
+{
+	return osmo_cc_helper_audio_negotiate_te(msg, session_p, codec_p, NULL);
+}
+
+int osmo_cc_helper_audio_negotiate_te(osmo_cc_msg_t *msg, osmo_cc_session_t **session_p, osmo_cc_session_codec_t **codec_p, osmo_cc_session_codec_t **telephone_event_p)
 {
 	char sdp[65536];
 	osmo_cc_session_media_t *media;
+	osmo_cc_session_codec_t *codec;
 	int rc;
 
 	if (!(*session_p)) {
@@ -178,10 +191,17 @@ int osmo_cc_helper_audio_negotiate(osmo_cc_msg_t *msg, osmo_cc_session_t **sessi
 			/* skip not accepted codecs */
 			if (!codec->accepted)
 				continue;
-			/* select first codec, if one was accpeted */
-			if (!(*codec_p)) {
-				LOGP(DCC, LOGL_DEBUG, "Select codec '%s'.\n", codec->payload_name);
-				*codec_p = codec;
+			if (!!strcasecmp(codec->payload_name, "telephone-event")) {
+				/* select first codec, if one was accpeted */
+				if (!(*codec_p)) {
+					LOGP(DCC, LOGL_DEBUG, "Select codec '%s'.\n", codec->payload_name);
+					*codec_p = codec;
+				}
+			} else {
+				if (telephone_event_p && !(*telephone_event_p)) {
+					LOGP(DCC, LOGL_DEBUG, "select telephone event codec.\n");
+					*telephone_event_p = codec;
+				}
 			}
 		}
 		if (*codec_p) {
diff --git a/src/libosmocc/helper.h b/src/libosmocc/helper.h
index 9b18ac0..a48bd8e 100644
--- a/src/libosmocc/helper.h
+++ b/src/libosmocc/helper.h
@@ -9,5 +9,7 @@ struct osmo_cc_helper_audio_codecs {
 
 osmo_cc_session_t *osmo_cc_helper_audio_offer(osmo_cc_session_config_t *conf, void *priv, struct osmo_cc_helper_audio_codecs *codecs, void (*receiver)(struct osmo_cc_session_codec *codec, uint8_t marker, uint16_t sequence_number, uint32_t timestamp, uint32_t ssrc, uint8_t *data, int len), osmo_cc_msg_t *msg, int debug);
 const char *osmo_cc_helper_audio_accept(osmo_cc_session_config_t *conf, void *priv, struct osmo_cc_helper_audio_codecs *codecs, void (*receiver)(struct osmo_cc_session_codec *codec, uint8_t marker, uint16_t sequence_number, uint32_t timestamp, uint32_t ssrc, uint8_t *data, int len), osmo_cc_msg_t *msg, osmo_cc_session_t **session_p, osmo_cc_session_codec_t **codec_p, int force_our_codec);
+const char *osmo_cc_helper_audio_accept_te(osmo_cc_session_config_t *conf, void *priv, struct osmo_cc_helper_audio_codecs *codecs, void (*receiver)(struct osmo_cc_session_codec *codec, uint8_t marker, uint16_t sequence_number, uint32_t timestamp, uint32_t ssrc, uint8_t *data, int len), osmo_cc_msg_t *msg, osmo_cc_session_t **session_p, osmo_cc_session_codec_t **codec_p, osmo_cc_session_codec_t **telephone_event_p, int force_our_codec);
 int osmo_cc_helper_audio_negotiate(osmo_cc_msg_t *msg, osmo_cc_session_t **session_p, osmo_cc_session_codec_t **codec_p);
+int osmo_cc_helper_audio_negotiate_te(osmo_cc_msg_t *msg, osmo_cc_session_t **session_p, osmo_cc_session_codec_t **codec_p, osmo_cc_session_codec_t **telephone_event_p);
 
diff --git a/src/libosmocc/rtp.c b/src/libosmocc/rtp.c
index 31104b7..84f15a7 100644
--- a/src/libosmocc/rtp.c
+++ b/src/libosmocc/rtp.c
@@ -366,6 +366,30 @@ void osmo_cc_rtp_send(osmo_cc_session_codec_t *codec, uint8_t *data, int len, ui
 		free(payload);
 }
 
+/* dito, but with absolute sequence and timestamp */
+void osmo_cc_rtp_send_ts(osmo_cc_session_codec_t *codec, uint8_t *data, int len, uint8_t marker, uint16_t tx_sequence, uint32_t tx_timestamp, void *priv)
+{
+	uint8_t *payload = NULL;
+	int payload_len = 0;
+
+	if (!codec || !codec->media->rtp_ofd.fd)
+		return;
+
+	if (codec->encoder)
+		codec->encoder(data, len, &payload, &payload_len, priv);
+	else {
+		payload = data;
+		payload_len = len;
+	}
+
+	rtp_send(&codec->media->rtp_sa, codec->media->rtp_slen, codec->media->rtp_ofd.fd, payload, payload_len, marker, codec->payload_type_remote, tx_sequence, tx_timestamp, codec->media->tx_ssrc);
+	codec->media->tx_sequence = tx_sequence;
+	codec->media->tx_timestamp = tx_timestamp;
+
+	if (codec->encoder)
+		free(payload);
+}
+
 static void check_port_translation(struct sockaddr_storage *sa, struct sockaddr_storage *media_sa, const char *what)
 {
 	struct sockaddr_in6 *sa6, *sa6_2;
diff --git a/src/libosmocc/rtp.h b/src/libosmocc/rtp.h
index ea1b31f..854c253 100644
--- a/src/libosmocc/rtp.h
+++ b/src/libosmocc/rtp.h
@@ -3,5 +3,6 @@ void osmo_cc_set_rtp_ports(osmo_cc_session_config_t *conf, uint16_t from, uint16
 int osmo_cc_rtp_open(osmo_cc_session_media_t *media);
 int osmo_cc_rtp_connect(osmo_cc_session_media_t *media);
 void osmo_cc_rtp_send(osmo_cc_session_codec_t *codec, uint8_t *data, int len, uint8_t marker, int inc_sequence, int inc_timestamp, void *priv);
+void osmo_cc_rtp_send_ts(osmo_cc_session_codec_t *codec, uint8_t *data, int len, uint8_t marker, uint16_t tx_sequence, uint32_t tx_timestamp, void *priv);
 void osmo_cc_rtp_close(osmo_cc_session_media_t *media);