diff --git a/smack-experimental/src/main/java/org/jivesoftware/smackx/jet/JetManager.java b/smack-experimental/src/main/java/org/jivesoftware/smackx/jet/JetManager.java
index 38ecf0613..e3f549bc0 100644
--- a/smack-experimental/src/main/java/org/jivesoftware/smackx/jet/JetManager.java
+++ b/smack-experimental/src/main/java/org/jivesoftware/smackx/jet/JetManager.java
@@ -101,7 +101,7 @@ public final class JetManager extends Manager implements JingleDescriptionManage
 
         JetSecurity security = new JetSecurity(method, recipient, content.getName(), Aes256GcmNoPadding.NAMESPACE);
         content.setSecurity(security);
-        session.initiate(connection());
+        session.sendInitiate(connection());
 
         return offer;
     }
diff --git a/smack-experimental/src/main/java/org/jivesoftware/smackx/jft/JingleFileTransferManager.java b/smack-experimental/src/main/java/org/jivesoftware/smackx/jft/JingleFileTransferManager.java
index 004c72dda..4988f5683 100644
--- a/smack-experimental/src/main/java/org/jivesoftware/smackx/jft/JingleFileTransferManager.java
+++ b/smack-experimental/src/main/java/org/jivesoftware/smackx/jft/JingleFileTransferManager.java
@@ -46,6 +46,7 @@ import org.jivesoftware.smackx.jingle.JingleManager;
 import org.jivesoftware.smackx.jingle.JingleTransportManager;
 import org.jivesoftware.smackx.jingle.component.JingleContent;
 import org.jivesoftware.smackx.jingle.component.JingleSession;
+import org.jivesoftware.smackx.jingle.component.JingleTransport;
 import org.jivesoftware.smackx.jingle.element.JingleContentElement;
 import org.jivesoftware.smackx.jingle.util.Role;
 
@@ -109,9 +110,10 @@ public final class JingleFileTransferManager extends Manager implements JingleDe
         content.setDescription(offer);
 
         JingleTransportManager transportManager = jingleManager.getBestAvailableTransportManager(to);
-        content.setTransport(transportManager.createTransportForInitiator(content));
+        JingleTransport<?> transport = transportManager.createTransportForInitiator(content);
+        content.setTransport(transport);
 
-        session.initiate(connection());
+        session.sendInitiate(connection());
 
         return offer;
     }
diff --git a/smack-experimental/src/main/java/org/jivesoftware/smackx/jft/component/JingleIncomingFileOffer.java b/smack-experimental/src/main/java/org/jivesoftware/smackx/jft/component/JingleIncomingFileOffer.java
index 3b5c3959c..df5da5ad5 100644
--- a/smack-experimental/src/main/java/org/jivesoftware/smackx/jft/component/JingleIncomingFileOffer.java
+++ b/smack-experimental/src/main/java/org/jivesoftware/smackx/jft/component/JingleIncomingFileOffer.java
@@ -125,7 +125,7 @@ public class JingleIncomingFileOffer extends AbstractJingleFileOffer<RemoteFile>
         this.target = target;
         JingleSession session = getParent().getParent();
         if (session.getSessionState() == JingleSession.SessionState.pending) {
-            session.accept(connection);
+            session.sendAccept(connection);
         }
 
         return null;
diff --git a/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/component/JingleSession.java b/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/component/JingleSession.java
index 2f411c532..272c0d1e8 100644
--- a/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/component/JingleSession.java
+++ b/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/component/JingleSession.java
@@ -92,7 +92,7 @@ public class JingleSession {
         return session;
     }
 
-    public void initiate(XMPPConnection connection) throws SmackException.NotConnectedException, InterruptedException, XMPPException.XMPPErrorException, SmackException.NoResponseException {
+    public void sendInitiate(XMPPConnection connection) throws SmackException.NotConnectedException, InterruptedException, XMPPException.XMPPErrorException, SmackException.NoResponseException {
         if (this.sessionState != SessionState.fresh) {
             throw new IllegalStateException("Session is not in fresh state.");
         }
@@ -101,7 +101,7 @@ public class JingleSession {
         this.sessionState = SessionState.pending;
     }
 
-    public void accept(XMPPConnection connection) throws SmackException.NotConnectedException, InterruptedException, XMPPException.XMPPErrorException, SmackException.NoResponseException {
+    public void sendAccept(XMPPConnection connection) throws SmackException.NotConnectedException, InterruptedException, XMPPException.XMPPErrorException, SmackException.NoResponseException {
         LOGGER.log(Level.INFO, "Accepted session.");
         if (this.sessionState != SessionState.pending) {
             throw new IllegalStateException("Session is not in pending state.");
@@ -379,6 +379,9 @@ public class JingleSession {
     }
 
     public void addContent(JingleContent content) {
+        if (contents.get(content.getName()) != null) {
+            throw new IllegalArgumentException("Session already contains a content with the name " + content.getName());
+        }
         contents.put(content.getName(), content);
         content.setParent(this);
     }
diff --git a/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/transport/jingle_s5b/JingleS5BTransport.java b/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/transport/jingle_s5b/JingleS5BTransport.java
index 59a1d9ded..62870805d 100644
--- a/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/transport/jingle_s5b/JingleS5BTransport.java
+++ b/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/transport/jingle_s5b/JingleS5BTransport.java
@@ -202,7 +202,7 @@ public class JingleS5BTransport extends JingleTransport<JingleS5BTransportElemen
     public void prepare(XMPPConnection connection) {
         JingleSession session = getParent().getParent();
         if (getOurDstAddr() == null) {
-            ourDstAddr = Socks5Utils.createDigest(session.getSessionId(), session.getOurJid(), session.getPeer());
+            ourDstAddr = Socks5Utils.createDigest(getSid(), session.getOurJid(), session.getPeer());
             Socks5Proxy.getSocks5Proxy().addTransfer(ourDstAddr);
         }
 
diff --git a/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/transport/jingle_s5b/JingleS5BTransportManager.java b/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/transport/jingle_s5b/JingleS5BTransportManager.java
index d2bca38c9..15c57773e 100644
--- a/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/transport/jingle_s5b/JingleS5BTransportManager.java
+++ b/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/transport/jingle_s5b/JingleS5BTransportManager.java
@@ -99,8 +99,9 @@ public final class JingleS5BTransportManager extends Manager implements JingleTr
     @Override
     public JingleTransport<?> createTransportForInitiator(JingleContent content) {
         JingleSession session = content.getParent();
+        String sid = StringUtils.randomString(24);
         List<JingleTransportCandidate<?>> candidates = collectCandidates();
-        return new JingleS5BTransport(session.getInitiator(), session.getResponder(), StringUtils.randomString(24), Bytestream.Mode.tcp, candidates);
+        return new JingleS5BTransport(session.getInitiator(), session.getResponder(), sid, Bytestream.Mode.tcp, candidates);
     }
 
     @Override