diff --git a/src/org/linphone/LinphonePreferences.java b/src/org/linphone/LinphonePreferences.java
index 002f3b8ac..5bb5b4c0c 100644
--- a/src/org/linphone/LinphonePreferences.java
+++ b/src/org/linphone/LinphonePreferences.java
@@ -349,15 +349,24 @@ public class LinphonePreferences {
 			LinphoneAddress proxyAddr;
 			try {
 				proxyAddr = LinphoneCoreFactory.instance().createLinphoneAddress(proxyConfig.getProxy());
-
+                int port = 0;
 				if (transport.equals(getString(R.string.pref_transport_udp_key))) {
 					proxyAddr.setTransport(TransportType.LinphoneTransportUdp);
 				} else if (transport.equals(getString(R.string.pref_transport_tcp_key))) {
 					proxyAddr.setTransport(TransportType.LinphoneTransportTcp);
 				} else if (transport.equals(getString(R.string.pref_transport_tls_key))) {
 					proxyAddr.setTransport(TransportType.LinphoneTransportTls);
+                    port = 5223;
 				}
 
+                /* 3G mobile firewall might block random TLS port, so we force use of 5223.
+                 * However we must NOT use this port when changing to TCP/UDP because otherwise
+                  * REGISTER (and everything actually) will fail...
+                  * */
+                if ("sip.linphone.org".equals(proxyConfig.getDomain())) {
+                    proxyAddr.setPort(port);
+                }
+
 				LinphoneProxyConfig prxCfg = getProxyConfig(n);
 				prxCfg.edit();
 				prxCfg.setProxy(proxyAddr.asStringUriOnly());
diff --git a/submodules/linphone b/submodules/linphone
index 273207b25..4ebc9c85b 160000
--- a/submodules/linphone
+++ b/submodules/linphone
@@ -1 +1 @@
-Subproject commit 273207b25c2087d665f45f3793c625dc5bf83545
+Subproject commit 4ebc9c85b954fd0e993a3f7e8890ae190fd8a79e