diff --git a/res/res_pjsip_multihomed.c b/res/res_pjsip_multihomed.c
new file mode 100644
index 0000000000000000000000000000000000000000..c959fa7777c239750f103783e8a6623c0a71df4e
--- /dev/null
+++ b/res/res_pjsip_multihomed.c
@@ -0,0 +1,187 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2014, Digium, Inc.
+ *
+ * Joshua Colp <jcolp@digium.com>
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+
+/*** MODULEINFO
+ <depend>pjproject</depend>
+ <depend>res_pjsip</depend>
+ <support_level>core</support_level>
+ ***/
+
+#include "asterisk.h"
+
+#include <pjsip.h>
+#include <pjsip_ua.h>
+
+#include "asterisk/res_pjsip.h"
+#include "asterisk/module.h"
+
+/*! \brief Local host address for IPv4 */
+static char host_ipv4[PJ_INET_ADDRSTRLEN + 2];
+
+/*! \brief Local host address for IPv6 */
+static char host_ipv6[PJ_INET6_ADDRSTRLEN + 2];
+
+/*! \brief Helper function which returns a UDP transport bound to the given address and port */
+static pjsip_transport *multihomed_get_udp_transport(pj_str_t *address, int port)
+{
+ struct ao2_container *transports = ast_sorcery_retrieve_by_fields(ast_sip_get_sorcery(), "transport",
+ AST_RETRIEVE_FLAG_MULTIPLE | AST_RETRIEVE_FLAG_ALL, NULL);
+ struct ast_sip_transport *transport;
+ struct ao2_iterator iter;
+ pjsip_transport *sip_transport = NULL;
+
+ if (!transports) {
+ return NULL;
+ }
+
+ for (iter = ao2_iterator_init(transports, 0); (transport = ao2_iterator_next(&iter)); ao2_ref(transport, -1)) {
+ if ((transport->type != AST_TRANSPORT_UDP) ||
+ (pj_strcmp(&transport->state->transport->local_name.host, address)) ||
+ (transport->state->transport->local_name.port != port)) {
+ continue;
+ }
+
+ sip_transport = transport->state->transport;
+ ao2_ref(transport, -1);
+ break;
+ }
+ ao2_iterator_destroy(&iter);
+
+ ao2_ref(transports, -1);
+
+ return sip_transport;
+}
+
+/*! \brief Helper function which determines if the address within SDP should be rewritten */
+static int multihomed_rewrite_sdp(struct pjmedia_sdp_session *sdp)
+{
+ if (!sdp->conn) {
+ return 0;
+ }
+
+ /* If the host address is used in the SDP replace it with the address of what this is going out on */
+ if ((!pj_strcmp2(&sdp->conn->addr_type, "IP4") && !pj_strcmp2(&sdp->conn->addr, host_ipv4)) ||
+ (!pj_strcmp2(&sdp->conn->addr_type, "IP6") && !pj_strcmp2(&sdp->conn->addr, host_ipv6))) {
+ return 1;
+ }
+
+ return 0;
+}
+
+static pj_status_t multihomed_on_tx_message(pjsip_tx_data *tdata)
+{
+ pjsip_tpmgr_fla2_param prm;
+ pjsip_transport *transport;
+ pjsip_contact_hdr *contact;
+ pjsip_via_hdr *via;
+
+ /* Use the destination information to determine what local interface this message will go out on */
+ pjsip_tpmgr_fla2_param_default(&prm);
+ prm.tp_type = tdata->tp_info.transport->key.type;
+ pj_strset2(&prm.dst_host, tdata->tp_info.dst_name);
+ prm.local_if = PJ_TRUE;
+
+ /* If we can't get the local address use best effort and let it pass */
+ if (pjsip_tpmgr_find_local_addr2(pjsip_endpt_get_tpmgr(ast_sip_get_pjsip_endpoint()), tdata->pool, &prm) != PJ_SUCCESS) {
+ return PJ_SUCCESS;
+ }
+
+ /* If the transport it is going out on is different reflect it in the message */
+ transport = multihomed_get_udp_transport(&prm.ret_addr, prm.ret_port);
+ if (transport && (tdata->tp_info.transport != transport)) {
+ tdata->tp_info.transport = transport;
+ }
+
+ /* If the message needs to be updated with new address do so */
+ contact = pjsip_msg_find_hdr(tdata->msg, PJSIP_H_CONTACT, NULL);
+ if (contact && (PJSIP_URI_SCHEME_IS_SIP(contact->uri) || PJSIP_URI_SCHEME_IS_SIPS(contact->uri))) {
+ pjsip_sip_uri *uri = pjsip_uri_get_uri(contact->uri);
+
+ /* prm.ret_addr is allocated from the tdata pool so it is perfectly fine to just do an assignment like this */
+ pj_strassign(&uri->host, &prm.ret_addr);
+ uri->port = prm.ret_port;
+
+ pjsip_tx_data_invalidate_msg(tdata);
+ }
+
+ if (tdata->msg->type == PJSIP_REQUEST_MSG && (via = pjsip_msg_find_hdr(tdata->msg, PJSIP_H_VIA, NULL))) {
+ pj_strassign(&via->sent_by.host, &prm.ret_addr);
+ via->sent_by.port = prm.ret_port;
+
+ pjsip_tx_data_invalidate_msg(tdata);
+ }
+
+ /* Update the SDP if it is present */
+ if (tdata->msg->body && ast_sip_is_content_type(&tdata->msg->body->content_type, "application", "sdp") &&
+ multihomed_rewrite_sdp(tdata->msg->body->data)) {
+ struct pjmedia_sdp_session *sdp = tdata->msg->body->data;
+ int stream;
+
+ pj_strassign(&sdp->conn->addr, &prm.ret_addr);
+
+ for (stream = 0; stream < sdp->media_count; ++stream) {
+ if (sdp->media[stream]->conn) {
+ pj_strassign(&sdp->media[stream]->conn->addr, &prm.ret_addr);
+ }
+ }
+
+ pjsip_tx_data_invalidate_msg(tdata);
+ }
+
+ return PJ_SUCCESS;
+}
+
+static pjsip_module multihomed_module = {
+ .name = { "Multihomed Routing", 18 },
+ .id = -1,
+ .priority = PJSIP_MOD_PRIORITY_TSX_LAYER - 1,
+ .on_tx_request = multihomed_on_tx_message,
+ .on_tx_response = multihomed_on_tx_message,
+};
+
+static int unload_module(void)
+{
+ ast_sip_unregister_service(&multihomed_module);
+ return 0;
+}
+
+static int load_module(void)
+{
+ pj_sockaddr addr;
+
+ if (!pj_gethostip(pj_AF_INET(), &addr)) {
+ pj_sockaddr_print(&addr, host_ipv4, sizeof(host_ipv4), 2);
+ }
+
+ if (!pj_gethostip(pj_AF_INET6(), &addr)) {
+ pj_sockaddr_print(&addr, host_ipv6, sizeof(host_ipv6), 2);
+ }
+
+ if (ast_sip_register_service(&multihomed_module)) {
+ ast_log(LOG_ERROR, "Could not register multihomed module for incoming and outgoing requests\n");
+ return AST_MODULE_LOAD_FAILURE;
+ }
+
+ return AST_MODULE_LOAD_SUCCESS;
+}
+
+AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "PJSIP Multihomed Routing Support",
+ .load = load_module,
+ .unload = unload_module,
+ .load_pri = AST_MODPRI_APP_DEPEND,
+ );