diff --git a/streaming/StreamTransferTask.java b/streaming/StreamTransferTask.java
new file mode 100644
index 0000000000..a3dd10f1ca
--- /dev/null
+++ b/streaming/StreamTransferTask.java
@@ -0,0 +1,156 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.cassandra.streaming;
+
+import java.util.*;
+import java.util.concurrent.*;
+import java.util.concurrent.ScheduledFuture;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import org.apache.cassandra.concurrent.NamedThreadFactory;
+import org.apache.cassandra.io.sstable.format.SSTableReader;
+import org.apache.cassandra.streaming.messages.OutgoingFileMessage;
+import org.apache.cassandra.utils.Pair;
+
+/**
+ * StreamTransferTask sends sections of SSTable files in certain ColumnFamily.
+ */
+public class StreamTransferTask extends StreamTask
+{
+    private static final ScheduledExecutorService timeoutExecutor = Executors.newSingleThreadScheduledExecutor(new NamedThreadFactory("StreamingTransferTaskTimeouts"));
+
+    private final AtomicInteger sequenceNumber = new AtomicInteger(0);
+    private boolean aborted = false;
+
+    private final Map<Integer, OutgoingFileMessage> files = new HashMap<>();
+    private final Map<Integer, ScheduledFuture> timeoutTasks = new HashMap<>();
+
+    private long totalSize;
+
+    public StreamTransferTask(StreamSession session, UUID cfId)
+    {
+        super(session, cfId);
+    }
+
+    public synchronized void addTransferFile(SSTableReader sstable, long estimatedKeys, List<Pair<Long, Long>> sections, long repairedAt)
+    {
+        assert sstable != null && cfId.equals(sstable.metadata.cfId);
+        OutgoingFileMessage message = new OutgoingFileMessage(sstable, sequenceNumber.getAndIncrement(), estimatedKeys, sections, repairedAt, session.keepSSTableLevel());
+        files.put(message.header.sequenceNumber, message);
+        totalSize += message.header.size();
+    }
+
+    /**
+     * Received ACK for file at {@code sequenceNumber}.
+     *
+     * @param sequenceNumber sequence number of file
+     */
+    public void complete(int sequenceNumber)
+    {
+        boolean signalComplete;
+        synchronized (this)
+        {
+            ScheduledFuture timeout = timeoutTasks.remove(sequenceNumber);
+            if (timeout != null)
+                timeout.cancel(false);
+
+            OutgoingFileMessage file = files.remove(sequenceNumber);
+            if (file != null)
+                file.sstable.releaseReference();
+
+            signalComplete = files.isEmpty();
+        }
+
+        // all file sent, notify session this task is complete.
+        if (signalComplete)
+            session.taskCompleted(this);
+    }
+
+    public synchronized void abort()
+    {
+        if (aborted)
+            return;
+        aborted = true;
+
+        for (ScheduledFuture future : timeoutTasks.values())
+            future.cancel(false);
+        timeoutTasks.clear();
+
+        for (OutgoingFileMessage file : files.values())
+            file.sstable.releaseReference();
+    }
+
+    public synchronized int getTotalNumberOfFiles()
+    {
+        return files.size();
+    }
+
+    public long getTotalSize()
+    {
+        return totalSize;
+    }
+
+    public synchronized Collection<OutgoingFileMessage> getFileMessages()
+    {
+        // We may race between queuing all those messages and the completion of the completion of
+        // the first ones. So copy tthe values to avoid a ConcurrentModificationException
+        return new ArrayList<>(files.values());
+    }
+
+    public synchronized OutgoingFileMessage createMessageForRetry(int sequenceNumber)
+    {
+        // remove previous time out task to be rescheduled later
+        ScheduledFuture future = timeoutTasks.remove(sequenceNumber);
+        if (future != null)
+            future.cancel(false);
+        return files.get(sequenceNumber);
+    }
+
+    /**
+     * Schedule timeout task to release reference for file sent.
+     * When not receiving ACK after sending to receiver in given time,
+     * the task will release reference.
+     *
+     * @param sequenceNumber sequence number of file sent.
+     * @param time time to timeout
+     * @param unit unit of given time
+     * @return scheduled future for timeout task
+     */
+    public synchronized ScheduledFuture scheduleTimeout(final int sequenceNumber, long time, TimeUnit unit)
+    {
+        if (!files.containsKey(sequenceNumber))
+            return null;
+
+        ScheduledFuture future = timeoutExecutor.schedule(new Runnable()
+        {
+            public void run()
+            {
+                synchronized (StreamTransferTask.this)
+                {
+                    // remove so we don't cancel ourselves
+                    timeoutTasks.remove(sequenceNumber);
+                    StreamTransferTask.this.complete(sequenceNumber);
+                }
+            }
+        }, time, unit);
+
+        ScheduledFuture prev = timeoutTasks.put(sequenceNumber, future);
+        assert prev == null;
+        return future;
+    }
+}