diff --git a/CHANGES b/CHANGES
index 27cc326046..b03398e033 100644
--- a/CHANGES
+++ b/CHANGES
@@ -76,6 +76,13 @@ res_pjsip_pubsub
    need to run the "alembic upgrade head" process to add the column to
    the schema.
 
+res_pjsip_transport_management
+------------------
+ * Since res_pjsip_transport_management provides several attack
+   mitigation features, its functionality moved to res_pjsip and
+   this module has been removed.  This way the features will always
+   be available if res_pjsip is loaded.
+
 ------------------------------------------------------------------------------
 --- Functionality changes from Asterisk 13.18.0 to Asterisk 13.19.0 ----------
 ------------------------------------------------------------------------------
diff --git a/UPGRADE.txt b/UPGRADE.txt
index 630c69690f..bbb083e962 100644
--- a/UPGRADE.txt
+++ b/UPGRADE.txt
@@ -56,6 +56,13 @@ res_pjsip_endpoint_identifier_ip
    you can now predict which endpoint is matched when a request comes in that
    matches both.
 
+res_pjsip_transport_management
+------------------
+ * Since res_pjsip_transport_management provides several attack
+   mitigation features, its functionality moved to res_pjsip and
+   this module has been removed.  This way the features will always
+   be available if res_pjsip is loaded.
+
 From 13.17.0 to 13.18.0:
 
 Core:
diff --git a/res/res_pjsip.c b/res/res_pjsip.c
index 7c8aabff11..75b34abf4a 100644
--- a/res/res_pjsip.c
+++ b/res/res_pjsip.c
@@ -4476,9 +4476,15 @@ static void supplement_outgoing_response(pjsip_tx_data *tdata, struct ast_sip_en
 
 int ast_sip_send_response(pjsip_response_addr *res_addr, pjsip_tx_data *tdata, struct ast_sip_endpoint *sip_endpoint)
 {
+	pj_status_t status;
+
 	supplement_outgoing_response(tdata, sip_endpoint);
+	status = pjsip_endpt_send_response(ast_sip_get_pjsip_endpoint(), res_addr, tdata, NULL, NULL);
+	if (status != PJ_SUCCESS) {
+		pjsip_tx_data_dec_ref(tdata);
+	}
 
-	return pjsip_endpt_send_response(ast_sip_get_pjsip_endpoint(), res_addr, tdata, NULL, NULL);
+	return status == PJ_SUCCESS ? 0 : -1;
 }
 
 int ast_sip_send_stateful_response(pjsip_rx_data *rdata, pjsip_tx_data *tdata, struct ast_sip_endpoint *sip_endpoint)
@@ -4731,6 +4737,7 @@ static int unload_pjsip(void *data)
 		internal_sip_destroy_outbound_authentication();
 		ast_res_pjsip_cleanup_message_filter();
 		ast_sip_destroy_distributor();
+		ast_sip_destroy_transport_management();
 		ast_res_pjsip_destroy_configuration();
 		ast_sip_destroy_system();
 		ast_sip_destroy_global_headers();
@@ -4893,6 +4900,11 @@ static int load_module(void)
 		goto error;
 	}
 
+	if (ast_sip_initialize_transport_management()) {
+		ast_log(LOG_ERROR, "Failed to initialize SIP transport management. Aborting load\n");
+		goto error;
+	}
+
 	if (ast_sip_initialize_distributor()) {
 		ast_log(LOG_ERROR, "Failed to register distributor module. Aborting load\n");
 		goto error;
diff --git a/res/res_pjsip/include/res_pjsip_private.h b/res/res_pjsip/include/res_pjsip_private.h
index 7bffd2b6f5..8c271eb695 100644
--- a/res/res_pjsip/include/res_pjsip_private.h
+++ b/res/res_pjsip/include/res_pjsip_private.h
@@ -433,4 +433,32 @@ void internal_res_pjsip_unref(void);
 int ast_sip_will_uri_survive_restart(pjsip_sip_uri *uri, struct ast_sip_endpoint *endpoint,
 	pjsip_rx_data *rdata);
 
+/*!
+ * \internal
+ * \brief Initialize the transport management module
+ * \since 13.20.0
+ *
+ * The transport management module is responsible for 3 things...
+ * 1.  It automatically destroys any reliable transport that does not
+ * receive a valid request within system/timer_b milliseconds of the
+ * connection being opened. (Attack mitigation)
+ * 2.  Since it increments the reliable transport's reference count
+ * for that period of time, it also prevents issues if the transport
+ * disconnects while we're still trying to process a response.
+ *  (Attack mitigation)
+ * 3.  If enabled by global/keep_alive_interval, it sends '\r\n'
+ * keepalives on reliable transports at the interval specified.
+ *
+ * \retval -1 Failure
+ * \retval 0 Success
+ */
+int ast_sip_initialize_transport_management(void);
+
+/*!
+ * \internal
+ * \brief Destruct the transport management module.
+ * \since 13.20.0
+ */
+void ast_sip_destroy_transport_management(void);
+
 #endif /* RES_PJSIP_PRIVATE_H_ */
diff --git a/res/res_pjsip/pjsip_distributor.c b/res/res_pjsip/pjsip_distributor.c
index 591d7fea76..e056b608ec 100644
--- a/res/res_pjsip/pjsip_distributor.c
+++ b/res/res_pjsip/pjsip_distributor.c
@@ -844,7 +844,9 @@ static pj_bool_t authenticate(pjsip_rx_data *rdata)
 		case AST_SIP_AUTHENTICATION_CHALLENGE:
 			/* Send the 401 we created for them */
 			ast_sip_report_auth_challenge_sent(endpoint, rdata, tdata);
-			pjsip_endpt_send_response2(ast_sip_get_pjsip_endpoint(), rdata, tdata, NULL, NULL);
+			if (pjsip_endpt_send_response2(ast_sip_get_pjsip_endpoint(), rdata, tdata, NULL, NULL) != PJ_SUCCESS) {
+				pjsip_tx_data_dec_ref(tdata);
+			}
 			return PJ_TRUE;
 		case AST_SIP_AUTHENTICATION_SUCCESS:
 			/* See note in endpoint_lookup about not holding an unnecessary write lock */
@@ -857,7 +859,9 @@ static pj_bool_t authenticate(pjsip_rx_data *rdata)
 		case AST_SIP_AUTHENTICATION_FAILED:
 			log_failed_request(rdata, "Failed to authenticate", 0, 0);
 			ast_sip_report_auth_failed_challenge_response(endpoint, rdata);
-			pjsip_endpt_send_response2(ast_sip_get_pjsip_endpoint(), rdata, tdata, NULL, NULL);
+			if (pjsip_endpt_send_response2(ast_sip_get_pjsip_endpoint(), rdata, tdata, NULL, NULL) != PJ_SUCCESS) {
+				pjsip_tx_data_dec_ref(tdata);
+			}
 			return PJ_TRUE;
 		case AST_SIP_AUTHENTICATION_ERROR:
 			log_failed_request(rdata, "Error to authenticate", 0, 0);
diff --git a/res/res_pjsip_transport_management.c b/res/res_pjsip/pjsip_transport_management.c
similarity index 94%
rename from res/res_pjsip_transport_management.c
rename to res/res_pjsip/pjsip_transport_management.c
index eb92eb7a51..efda37d7cb 100644
--- a/res/res_pjsip_transport_management.c
+++ b/res/res_pjsip/pjsip_transport_management.c
@@ -16,12 +16,6 @@
  * at the top of the source tree.
  */
 
-/*** MODULEINFO
-	<depend>pjproject</depend>
-	<depend>res_pjsip</depend>
-	<support_level>core</support_level>
- ***/
-
 #include "asterisk.h"
 
 #include <signal.h>
@@ -32,6 +26,7 @@
 #include "asterisk/res_pjsip.h"
 #include "asterisk/module.h"
 #include "asterisk/astobj2.h"
+#include "include/res_pjsip_private.h"
 
 /*! \brief Number of buckets for monitored transports */
 #define TRANSPORTS_BUCKETS 127
@@ -319,12 +314,10 @@ static pjsip_module idle_monitor_module = {
 	.on_rx_request = idle_monitor_on_rx_request,
 };
 
-static int load_module(void)
+int ast_sip_initialize_transport_management(void)
 {
 	struct ao2_container *transports;
 
-	CHECK_PJSIP_MODULE_LOADED();
-
 	transports = ao2_container_alloc(TRANSPORTS_BUCKETS, monitored_transport_hash_fn,
 		monitored_transport_cmp_fn);
 	if (!transports) {
@@ -356,11 +349,10 @@ static int load_module(void)
 	ast_sorcery_observer_add(ast_sip_get_sorcery(), "global", &keepalive_global_observer);
 	ast_sorcery_reload_object(ast_sip_get_sorcery(), "global");
 
-	ast_module_shutdown_ref(ast_module_info->self);
 	return AST_MODULE_LOAD_SUCCESS;
 }
 
-static int unload_module(void)
+void ast_sip_destroy_transport_management(void)
 {
 	if (keepalive_interval) {
 		keepalive_interval = 0;
@@ -381,20 +373,4 @@ static int unload_module(void)
 	sched = NULL;
 
 	ao2_global_obj_release(monitored_transports);
-
-	return 0;
-}
-
-static int reload_module(void)
-{
-	ast_sorcery_reload_object(ast_sip_get_sorcery(), "global");
-	return 0;
 }
-
-AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "PJSIP Reliable Transport Management",
-	.support_level = AST_MODULE_SUPPORT_CORE,
-	.load = load_module,
-	.reload = reload_module,
-	.unload = unload_module,
-	.load_pri = AST_MODPRI_CHANNEL_DEPEND - 4,
-);
diff --git a/res/res_pjsip_session.c b/res/res_pjsip_session.c
index 8939f4345b..d74796e519 100644
--- a/res/res_pjsip_session.c
+++ b/res/res_pjsip_session.c
@@ -1083,7 +1083,9 @@ static pj_bool_t session_reinvite_on_rx_request(pjsip_rx_data *rdata)
 
 		/* Otherwise this is a new re-invite, so reject it */
 		if (pjsip_dlg_create_response(dlg, rdata, 491, NULL, &tdata) == PJ_SUCCESS) {
-			pjsip_endpt_send_response2(ast_sip_get_pjsip_endpoint(), rdata, tdata, NULL, NULL);
+			if (pjsip_endpt_send_response2(ast_sip_get_pjsip_endpoint(), rdata, tdata, NULL, NULL) != PJ_SUCCESS) {
+				pjsip_tx_data_dec_ref(tdata);
+			}
 		}
 
 		return PJ_TRUE;
@@ -2051,7 +2053,9 @@ static pjsip_inv_session *pre_session_setup(pjsip_rx_data *rdata, const struct a
 
 	if (pjsip_inv_verify_request(rdata, &options, NULL, NULL, ast_sip_get_pjsip_endpoint(), &tdata) != PJ_SUCCESS) {
 		if (tdata) {
-			pjsip_endpt_send_response2(ast_sip_get_pjsip_endpoint(), rdata, tdata, NULL, NULL);
+			if (pjsip_endpt_send_response2(ast_sip_get_pjsip_endpoint(), rdata, tdata, NULL, NULL) != PJ_SUCCESS) {
+				pjsip_tx_data_dec_ref(tdata);
+			}
 		} else {
 			pjsip_endpt_respond_stateless(ast_sip_get_pjsip_endpoint(), rdata, 500, NULL, NULL, NULL);
 		}
