diff --git a/include/asterisk/rtp_engine.h b/include/asterisk/rtp_engine.h
index b3519f9176..0a38e43cd5 100644
--- a/include/asterisk/rtp_engine.h
+++ b/include/asterisk/rtp_engine.h
@@ -764,10 +764,15 @@ struct ast_rtp_codecs {
 	unsigned int framing;
 	/*! The preferred format, as the mappings are numerically sorted */
 	struct ast_format *preferred_format;
+	/*! The preferred dtmf sample rate */
+	int preferred_dtmf_rate;
+	/*! The preferred dtmf payload type */
+	int preferred_dtmf_pt;
 };
 
 #define AST_RTP_CODECS_NULL_INIT \
-    { .codecs_lock = AST_RWLOCK_INIT_VALUE, .payload_mapping_rx = { 0, }, .payload_mapping_tx = { 0, }, .framing = 0, .preferred_format = NULL }
+    { .codecs_lock = AST_RWLOCK_INIT_VALUE, .payload_mapping_rx = { 0, }, .payload_mapping_tx = { 0, }, .framing = 0, .preferred_format = NULL, \
+	.preferred_dtmf_rate = -1, .preferred_dtmf_pt = -1}
 
 /*! Structure that represents the glue that binds an RTP instance to a channel */
 struct ast_rtp_glue {
@@ -1710,6 +1715,69 @@ struct ast_format *ast_rtp_codecs_get_preferred_format(struct ast_rtp_codecs *co
  */
 int ast_rtp_codecs_set_preferred_format(struct ast_rtp_codecs *codecs, struct ast_format *format);
 
+/*!
+ * \brief Retrieve rx preferred dtmf format payload type
+ *
+ * \param codecs Codecs structure to look in
+ *
+ * \return Payload type of preferred dtmf format.
+ * \retval -1 if not set.
+ *
+ * Example usage:
+ *
+ * \code
+ * int payload;
+ * payload = ast_rtp_codecs_get_preferred_dtmf_format_pt(codec);
+ * \endcode
+ *
+ * This looks up the preferred dtmf format pt on the codec
+ */
+int ast_rtp_codecs_get_preferred_dtmf_format_pt(struct ast_rtp_codecs *codecs);
+
+/*!
+ * \brief Retrieve rx preferred dtmf format sample rate
+ *
+ * \param codecs Codecs structure to look in
+ *
+ * \return Sample rate of preferred dtmf format.
+ * \retval -1 if not set.
+ *
+ * Example usage:
+ *
+ * \code
+ * int sample_rate;
+ * sample_rate = ast_rtp_codecs_get_preferred_dtmf_format_rate(codec);
+ * \endcode
+ *
+ * This looks up the preferred dtmf format sample rate on the codec
+ */
+int ast_rtp_codecs_get_preferred_dtmf_format_rate(struct ast_rtp_codecs *codecs);
+
+/*!
+ * \brief Set the preferred dtmf format pt and sample rate
+ *
+ * \param codecs Codecs structure to set the preferred format in
+ * \param pt Preferred dtmf payload type to set.
+ * \param rate Preferred dtmf payload rate to set.
+ *
+ * \return 0
+ *
+ * \note The format passed this function has its reference count increased. If an existing
+ * 		 format is set, that format is replaced.
+ *
+ * Example usage:
+ *
+ * \code
+ * int dtmf_code = atoi(dtmf_pt);
+ * int dtmf_rate = clock_rate;
+ * ast_rtp_codecs_set_preferred_dtmf_format(codecs, dtmf_code, dtmf_rate);
+ * \endcode
+ *
+ * This sets the preferred dtmf_code and dtmf_rate on the codec.
+ */
+int ast_rtp_codecs_set_preferred_dtmf_format(struct ast_rtp_codecs *codecs, int pt, int rate);
+
+
 /*!
  * \brief Update the format associated with a tx payload type in a codecs structure
  *
@@ -2977,6 +3045,20 @@ int ast_rtp_get_rate(const struct ast_format *format);
  */
 struct stasis_topic *ast_rtp_topic(void);
 
+/*!
+ * \brief Determine if a type of payload is already present in mappings.
+ * \since 18
+ *
+ * \param codecs Codecs to be checked for mappings.
+ * \param to_match Payload type object to compare against.
+ *
+ * \note It is assumed that codecs is not locked before calling.
+ *
+ * \retval 0 not found
+ * \retval 1 found
+ */
+int ast_rtp_payload_mapping_tx_is_present(struct ast_rtp_codecs *codecs, const struct ast_rtp_payload_type *to_match);
+
 /* RTP debug logging category name */
 #define AST_LOG_CATEGORY_RTP "rtp"
 /* RTP packet debug logging category name */
diff --git a/main/rtp_engine.c b/main/rtp_engine.c
index 621f12ca00..6b2d67bd31 100644
--- a/main/rtp_engine.c
+++ b/main/rtp_engine.c
@@ -1217,6 +1217,16 @@ static int payload_mapping_tx_is_present(const struct ast_rtp_codecs *codecs, co
 	return 0;
 }
 
+int ast_rtp_payload_mapping_tx_is_present(struct ast_rtp_codecs *codecs, const struct ast_rtp_payload_type *to_match) {
+	int ret = 0;
+	if (codecs && to_match) {
+		ast_rwlock_rdlock(&codecs->codecs_lock);
+		ret = payload_mapping_tx_is_present(codecs, to_match);
+		ast_rwlock_unlock(&codecs->codecs_lock);
+	}
+	return ret;
+}
+
 /*!
  * \internal
  * \brief Copy the tx payload type mapping to the destination.
@@ -1289,6 +1299,8 @@ void ast_rtp_codecs_payloads_copy(struct ast_rtp_codecs *src, struct ast_rtp_cod
 	rtp_codecs_payloads_copy_tx(src, dest, instance);
 	dest->framing = src->framing;
 	ao2_replace(dest->preferred_format, src->preferred_format);
+	dest->preferred_dtmf_rate = src->preferred_dtmf_rate;
+	dest->preferred_dtmf_pt = src->preferred_dtmf_pt;
 
 	ast_rwlock_unlock(&src->codecs_lock);
 	ast_rwlock_unlock(&dest->codecs_lock);
@@ -1332,6 +1344,8 @@ void ast_rtp_codecs_payloads_xover(struct ast_rtp_codecs *src, struct ast_rtp_co
 
 	dest->framing = src->framing;
 	ao2_replace(dest->preferred_format, src->preferred_format);
+	dest->preferred_dtmf_rate = src->preferred_dtmf_rate;
+	dest->preferred_dtmf_pt = src->preferred_dtmf_pt;
 
 	if (src != dest) {
 		ast_rwlock_unlock(&src->codecs_lock);
@@ -1572,6 +1586,33 @@ int ast_rtp_codecs_set_preferred_format(struct ast_rtp_codecs *codecs, struct as
 	return 0;
 }
 
+int ast_rtp_codecs_get_preferred_dtmf_format_pt(struct ast_rtp_codecs *codecs)
+{
+	int pt = -1;
+	ast_rwlock_rdlock(&codecs->codecs_lock);
+	pt = codecs->preferred_dtmf_pt;
+	ast_rwlock_unlock(&codecs->codecs_lock);
+	return pt;
+}
+
+int ast_rtp_codecs_get_preferred_dtmf_format_rate(struct ast_rtp_codecs *codecs)
+{
+	int rate = -1;
+	ast_rwlock_rdlock(&codecs->codecs_lock);
+	rate = codecs->preferred_dtmf_rate;
+	ast_rwlock_unlock(&codecs->codecs_lock);
+	return rate;
+}
+
+int ast_rtp_codecs_set_preferred_dtmf_format(struct ast_rtp_codecs *codecs, int pt, int rate)
+{
+	ast_rwlock_wrlock(&codecs->codecs_lock);
+	codecs->preferred_dtmf_pt = pt;
+	codecs->preferred_dtmf_rate = rate;
+	ast_rwlock_unlock(&codecs->codecs_lock);
+	return 0;
+}
+
 int ast_rtp_codecs_payload_replace_format(struct ast_rtp_codecs *codecs, int payload, struct ast_format *format)
 {
 	struct ast_rtp_payload_type *type;
@@ -2087,6 +2128,16 @@ int ast_rtp_codecs_payload_code_tx_sample_rate(struct ast_rtp_codecs *codecs, in
 		ast_rwlock_rdlock(&static_RTP_PT_lock);
 		payload = find_static_payload_type(asterisk_format, format, code);
 		ast_rwlock_unlock(&static_RTP_PT_lock);
+
+		ast_rwlock_rdlock(&codecs->codecs_lock);
+		if (payload >= 0 && payload < AST_VECTOR_SIZE(&codecs->payload_mapping_tx)){
+			type = AST_VECTOR_GET(&codecs->payload_mapping_tx, payload);
+			if (!type || (sample_rate != 0 && type->sample_rate != sample_rate)) {
+				/* Don't use the type if we can't find it or it doesn't match the supplied sample_rate */
+				payload = -1;
+			}
+		}
+		ast_rwlock_unlock(&codecs->codecs_lock);
 	}
 
 	return payload;
diff --git a/res/res_pjsip_sdp_rtp.c b/res/res_pjsip_sdp_rtp.c
index 98df545397..4423dfda5c 100644
--- a/res/res_pjsip_sdp_rtp.c
+++ b/res/res_pjsip_sdp_rtp.c
@@ -344,6 +344,14 @@ static void get_codecs(struct ast_sip_session *session, const struct pjmedia_sdp
 
 		ast_copy_pj_str(name, &rtpmap->enc_name, sizeof(name));
 		if (strcmp(name, "telephone-event") == 0) {
+			if (tel_event == 0) {
+				int dtmf_rate = 0, dtmf_code = 0;
+				char dtmf_pt[8];
+				ast_copy_pj_str(dtmf_pt, &rtpmap->pt, sizeof(dtmf_pt));
+				dtmf_code = atoi(dtmf_pt);
+				dtmf_rate = rtpmap->clock_rate;
+				ast_rtp_codecs_set_preferred_dtmf_format(codecs, dtmf_code, dtmf_rate);
+			}
 			tel_event++;
 		}
 
diff --git a/res/res_rtp_asterisk.c b/res/res_rtp_asterisk.c
index c3314612eb..495e3de93f 100644
--- a/res/res_rtp_asterisk.c
+++ b/res/res_rtp_asterisk.c
@@ -4283,8 +4283,7 @@ static int ast_rtp_dtmf_begin(struct ast_rtp_instance *instance, char digit)
 {
 	struct ast_rtp *rtp = ast_rtp_instance_get_data(instance);
 	struct ast_sockaddr remote_address = { {0,} };
-	int hdrlen = 12, res = 0, i = 0, payload = 101;
-	unsigned int sample_rate = 8000;
+	int hdrlen = 12, res = 0, i = 0, payload = -1, sample_rate = -1;
 	char data[256];
 	unsigned int *rtpheader = (unsigned int*)data;
 	RAII_VAR(struct ast_format *, payload_format, NULL, ao2_cleanup);
@@ -4323,16 +4322,26 @@ static int ast_rtp_dtmf_begin(struct ast_rtp_instance *instance, char digit)
 		sample_rate = ast_format_get_sample_rate(rtp->lasttxformat);
 	}
 
-	/* Grab the matching DTMF type payload */
-	payload = ast_rtp_codecs_payload_code_tx_sample_rate(ast_rtp_instance_get_codecs(instance), 0, NULL, AST_RTP_DTMF, sample_rate);
+	if (sample_rate != -1) {
+		payload = ast_rtp_codecs_payload_code_tx_sample_rate(ast_rtp_instance_get_codecs(instance), 0, NULL, AST_RTP_DTMF, sample_rate);
+	}
 
-	/* If this returns -1, we are using a codec with a sample rate that does not have a matching RFC 2833/4733
-	   offer. The offer may have included a default-rate one that doesn't match the codec rate, so try to use that. */
-	if (payload == -1) {
+	if (payload == -1 ||
+		!ast_rtp_payload_mapping_tx_is_present(
+			ast_rtp_instance_get_codecs(instance), ast_rtp_codecs_get_payload(ast_rtp_instance_get_codecs(instance), payload))) {
+		/* Fall back to the preferred DTMF payload type and sample rate as either we couldn't find an audio codec to try and match
+		   sample rates with or we could, but a telephone-event matching that audio codec's sample rate was not included in the
+		   sdp negotiated by the far end. */
+		payload = ast_rtp_codecs_get_preferred_dtmf_format_pt(ast_rtp_instance_get_codecs(instance));
+		sample_rate = ast_rtp_codecs_get_preferred_dtmf_format_rate(ast_rtp_instance_get_codecs(instance));
+	}
+
+	/* The sdp negotiation has not yeilded a usable RFC 2833/4733 format. Try a default-rate one as a last resort. */
+	if (payload == -1 || sample_rate == -1) {
 		sample_rate = DEFAULT_DTMF_SAMPLE_RATE_MS;
 		payload = ast_rtp_codecs_payload_code_tx(ast_rtp_instance_get_codecs(instance), 0, NULL, AST_RTP_DTMF);
 	}
-	/* No default-rate offer either, trying to send a digit outside of what was negotiated for. */
+	/* Even trying a default payload has failed. We are trying to send a digit outside of what was negotiated for. */
 	if (payload == -1) {
 		return -1;
 	}