--- channels/chan_sip.c	2013-03-27 19:51:29.000000000 +0000
+++ ../../asterisk-11.4.0-rc1/channels/chan_sip.c	2013-04-13 01:40:43.028832054 +0000
@@ -1397,7 +1397,7 @@
 static int process_sdp_a_video(const char *a, struct sip_pvt *p, struct ast_rtp_codecs *newvideortp, int *last_rtpmap_codec);
 static int process_sdp_a_text(const char *a, struct sip_pvt *p, struct ast_rtp_codecs *newtextrtp, char *red_fmtp, int *red_num_gen, int *red_data_pt, int *last_rtpmap_codec);
 static int process_sdp_a_image(const char *a, struct sip_pvt *p);
-static void add_ice_to_sdp(struct ast_rtp_instance *instance, struct ast_str **a_buf);
+static void add_ice_to_sdp(struct ast_rtp_instance *instance, struct ast_str **a_buf, struct ast_sockaddr *dest);  // include public IP to fix https://issues.asterisk.org/jira/browse/ASTERISK-21383
 static void add_dtls_to_sdp(struct ast_rtp_instance *instance, struct ast_str **a_buf);
 static void start_ice(struct ast_rtp_instance *instance);
 static void add_codec_to_sdp(const struct sip_pvt *p, struct ast_format *codec,
@@ -12524,7 +12524,7 @@
 }
 
 /*! \brief Add ICE attributes to SDP */
-static void add_ice_to_sdp(struct ast_rtp_instance *instance, struct ast_str **a_buf)
+static void add_ice_to_sdp(struct ast_rtp_instance *instance, struct ast_str **a_buf, struct ast_sockaddr *dest)  // include public IP to fix https://issues.asterisk.org/jira/browse/ASTERISK-21383
 {
 	struct ast_rtp_engine_ice *ice = ast_rtp_instance_get_ice(instance);
 	const char *username, *password;
@@ -12548,7 +12548,18 @@
 
 	while ((candidate = ao2_iterator_next(&i))) {
 		ast_str_append(a_buf, 0, "a=candidate:%s %d %s %d ", candidate->foundation, candidate->id, candidate->transport, candidate->priority);
-		ast_str_append(a_buf, 0, "%s ", ast_sockaddr_stringify_host(&candidate->address));
+
+		if (candidate->type == AST_RTP_ICE_CANDIDATE_TYPE_HOST) {  
+                	ast_log(LOG_WARNING, "ASTERISK-21383 fix - replace host candidates Local IP with Public IP\n");
+                	ast_log(LOG_WARNING, "ASTERISK-21383 fix - Asterisk Local IP: %s\n", ast_sockaddr_stringify_host(&candidate->address));
+                	ast_log(LOG_WARNING, "ASTERISK-21383 fix - Asterisk Public IP: %s\n", ast_sockaddr_stringify_host(dest));
+			// for a host candidate, override local Asterisk IP with the Public IP
+                	ast_str_append(a_buf, 0, "%s ", ast_sockaddr_stringify_host(dest));   // https://issues.asterisk.org/jira/browse/ASTERISK-21383
+		} else {
+			// for a srflx or relay candidate, use the default candidate address
+			ast_str_append(a_buf, 0, "%s ", ast_sockaddr_stringify_host(&candidate->address));
+		}
+
 		ast_str_append(a_buf, 0, "%s typ ", ast_sockaddr_stringify_port(&candidate->address));
 
 		if (candidate->type == AST_RTP_ICE_CANDIDATE_TYPE_HOST) {
@@ -13113,7 +13124,7 @@
 
 			if (!doing_directmedia) {
 				if (ast_test_flag(&p->flags[2], SIP_PAGE3_ICE_SUPPORT)) {
-					add_ice_to_sdp(p->vrtp, &a_video);
+					add_ice_to_sdp(p->vrtp, &a_video, &dest);  // ASTERISK-21383 - Replace host candidate local IP with public IP
 				}
 
 				add_dtls_to_sdp(p->vrtp, &a_video);
@@ -13134,7 +13145,7 @@
 
 			if (!doing_directmedia) {
 				if (ast_test_flag(&p->flags[2], SIP_PAGE3_ICE_SUPPORT)) {
-					add_ice_to_sdp(p->trtp, &a_text);
+					add_ice_to_sdp(p->trtp, &a_text, &dest);  // ASTERISK-21383 - Replace host candidate local IP with public IP
 				}
 
 				add_dtls_to_sdp(p->trtp, &a_text);
@@ -13237,7 +13248,7 @@
 
 		if (!doing_directmedia) {
 			if (ast_test_flag(&p->flags[2], SIP_PAGE3_ICE_SUPPORT)) {
-				add_ice_to_sdp(p->rtp, &a_audio);
+				add_ice_to_sdp(p->rtp, &a_audio, &dest);  // ASTERISK-21383 - Replace host candidate local IP with public IP
 			}
 
 			add_dtls_to_sdp(p->rtp, &a_audio);