diff --git a/core/src/main/groovy/com/muwire/core/Core.groovy b/core/src/main/groovy/com/muwire/core/Core.groovy
index 73509f47..0c00a902 100644
--- a/core/src/main/groovy/com/muwire/core/Core.groovy
+++ b/core/src/main/groovy/com/muwire/core/Core.groovy
@@ -217,7 +217,7 @@ public class Core {
         eventBus.register(SourceDiscoveredEvent.class, downloadManager)
         
         log.info("initializing upload manager")
-        UploadManager uploadManager = new UploadManager(eventBus, fileManager)
+        UploadManager uploadManager = new UploadManager(eventBus, fileManager, meshManager)
         
         log.info("initializing connection establisher")
         connectionEstablisher = new ConnectionEstablisher(eventBus, i2pConnector, props, connectionManager, hostCache)
diff --git a/core/src/main/groovy/com/muwire/core/mesh/Mesh.groovy b/core/src/main/groovy/com/muwire/core/mesh/Mesh.groovy
index d18c75fb..2fd5546f 100644
--- a/core/src/main/groovy/com/muwire/core/mesh/Mesh.groovy
+++ b/core/src/main/groovy/com/muwire/core/mesh/Mesh.groovy
@@ -16,4 +16,13 @@ class Mesh {
         this.infoHash = infoHash
         this.pieces = pieces
     }
+    
+    Set<Destination> getRandom(int n, Destination exclude) {
+        List<Destination> tmp = new ArrayList<>(sources)
+        tmp.remove(exclude)
+        Collections.shuffle(tmp)
+        if (tmp.size() < n)
+            return tmp
+        tmp[0..n-1]
+    }
 }
diff --git a/core/src/main/groovy/com/muwire/core/upload/ContentUploader.groovy b/core/src/main/groovy/com/muwire/core/upload/ContentUploader.groovy
index 49da55d5..c4d433ee 100644
--- a/core/src/main/groovy/com/muwire/core/upload/ContentUploader.groovy
+++ b/core/src/main/groovy/com/muwire/core/upload/ContentUploader.groovy
@@ -5,18 +5,25 @@ import java.nio.channels.FileChannel
 import java.nio.charset.StandardCharsets
 import java.nio.file.Files
 import java.nio.file.StandardOpenOption
+import java.util.stream.Collectors
 
 import com.muwire.core.connection.Endpoint
+import com.muwire.core.mesh.Mesh
+import com.muwire.core.util.DataUtil
+
+import net.i2p.data.Destination
 
 class ContentUploader extends Uploader {
     
     private final File file
     private final ContentRequest request
+    private final Mesh mesh
     
-    ContentUploader(File file, ContentRequest request, Endpoint endpoint) {
+    ContentUploader(File file, ContentRequest request, Endpoint endpoint, Mesh mesh) {
         super(endpoint)
         this.file = file
         this.request = request
+        this.mesh = mesh
     }
     
     @Override
@@ -24,14 +31,18 @@ class ContentUploader extends Uploader {
         OutputStream os = endpoint.getOutputStream()
         Range range = request.getRange()
         if (range.start >= file.length() || range.end >= file.length()) {
-            os.write("416 Range Not Satisfiable\r\n\r\n".getBytes(StandardCharsets.US_ASCII))
+            os.write("416 Range Not Satisfiable\r\n".getBytes(StandardCharsets.US_ASCII))
+            writeMesh()
+            os.write("\r\n".getBytes(StandardCharsets.US_ASCII))
             os.flush()
             return
         }
 
         os.write("200 OK\r\n".getBytes(StandardCharsets.US_ASCII))
-        os.write("Content-Range: $range.start-$range.end\r\n\r\n".getBytes(StandardCharsets.US_ASCII))
-
+        os.write("Content-Range: $range.start-$range.end\r\n".getBytes(StandardCharsets.US_ASCII))
+        writeMesh()
+        os.write("\r\n".getBytes(StandardCharsets.US_ASCII))
+        
         FileChannel channel
         try {
             channel = Files.newByteChannel(file.toPath(), EnumSet.of(StandardOpenOption.READ))
@@ -50,6 +61,15 @@ class ContentUploader extends Uploader {
             endpoint.getOutputStream().flush()
         }
     }
+    
+    private void writeMesh() {
+        String xHave = DataUtil.encodeXHave(mesh.pieces.getDownloaded(), mesh.pieces.nPieces)
+        endpoint.getOutputStream().write("X-Have: $xHave\r\n".getBytes(StandardCharsets.US_ASCII))
+        
+        Set<Destination> sources = mesh.getRandom(3, endpoint.destination)
+        String xAlts = sources.stream().map({ it.toBase64() }).collect(Collectors.joining(","))
+        endpoint.getOutputStream().write("X-Alt: $xAlts\r\n".getBytes(StandardCharsets.US_ASCII))
+    }
 
     @Override
     public String getName() {
diff --git a/core/src/main/groovy/com/muwire/core/upload/UploadManager.groovy b/core/src/main/groovy/com/muwire/core/upload/UploadManager.groovy
index 3045ce08..b18a717d 100644
--- a/core/src/main/groovy/com/muwire/core/upload/UploadManager.groovy
+++ b/core/src/main/groovy/com/muwire/core/upload/UploadManager.groovy
@@ -8,6 +8,8 @@ import com.muwire.core.SharedFile
 import com.muwire.core.connection.Endpoint
 import com.muwire.core.download.SourceDiscoveredEvent
 import com.muwire.core.files.FileManager
+import com.muwire.core.mesh.Mesh
+import com.muwire.core.mesh.MeshManager
 
 import groovy.util.logging.Log
 import net.i2p.data.Base64
@@ -16,12 +18,14 @@ import net.i2p.data.Base64
 public class UploadManager {
     private final EventBus eventBus
     private final FileManager fileManager
+    private final MeshManager meshManager
     
     public UploadManager() {}
     
-    public UploadManager(EventBus eventBus, FileManager fileManager) {
+    public UploadManager(EventBus eventBus, FileManager fileManager, MeshManager meshManager) {
         this.eventBus = eventBus
         this.fileManager = fileManager
+        this.meshManager = meshManager
     }
     
     public void processGET(Endpoint e) throws IOException {
@@ -72,7 +76,10 @@ public class UploadManager {
             if (request.have) 
                 eventBus.publish(new SourceDiscoveredEvent(infoHash : request.infoHash, source : e.destination))
             
-            Uploader uploader = new ContentUploader(sharedFiles.iterator().next().file, request, e)
+            SharedFile file = sharedFiles.iterator().next();
+            Mesh mesh = meshManager.getOrCreate(request.infoHash, file.NPieces)    
+                
+            Uploader uploader = new ContentUploader(file.file, request, e, mesh)
             eventBus.publish(new UploadEvent(uploader : uploader))
             try {
                 uploader.respond()
@@ -162,7 +169,10 @@ public class UploadManager {
             if (request.have)
                 eventBus.publish(new SourceDiscoveredEvent(infoHash : request.infoHash, source : e.destination))
                 
-            uploader = new ContentUploader(sharedFiles.iterator().next().file, request, e)
+            SharedFile file = sharedFiles.iterator().next();
+            Mesh mesh = meshManager.getOrCreate(request.infoHash, file.NPieces)
+                
+            uploader = new ContentUploader(file.file, request, e, mesh)
             eventBus.publish(new UploadEvent(uploader : uploader))
             try {
                 uploader.respond()
diff --git a/core/src/main/java/com/muwire/core/SharedFile.java b/core/src/main/java/com/muwire/core/SharedFile.java
index 19c66c85..81072834 100644
--- a/core/src/main/java/com/muwire/core/SharedFile.java
+++ b/core/src/main/java/com/muwire/core/SharedFile.java
@@ -26,6 +26,15 @@ public class SharedFile {
 	    return pieceSize;
 	}
 	
+	public int getNPieces() {
+	    long length = file.length();
+	    int rawPieceSize = 0x1 << pieceSize;
+	    int rv = (int) (length / rawPieceSize);
+	    if (length % pieceSize != 0)
+	        rv++;
+	    return rv;
+	}
+	
 	@Override
 	public int hashCode() {
 	    return file.hashCode() ^ infoHash.hashCode();