diff --git a/briar-api/src/net/sf/briar/api/reliability/ReliabilityLayer.java b/briar-api/src/net/sf/briar/api/reliability/ReliabilityLayer.java
index ae1938039f7f7aed7bd4265b0f65a1b6108ad2ed..b997084aece1a47aee247e04edac8b5bd33c9bff 100644
--- a/briar-api/src/net/sf/briar/api/reliability/ReliabilityLayer.java
+++ b/briar-api/src/net/sf/briar/api/reliability/ReliabilityLayer.java
@@ -3,13 +3,34 @@ package net.sf.briar.api.reliability;
 import java.io.InputStream;
 import java.io.OutputStream;
 
+/**
+ * A protocol layer that attempts to ensure reliable, ordered delivery of data
+ * across an unreliable lower layer. Interactions with the lower layer use the
+ * buffer-oriented {@link ReadHandler} and {@link WriteHandler} interfaces; the
+ * reliability layer presents stream-oriented {@link java.io.InputStream} and
+ * {@link java.io.OutputStream} interfaces to higher layers.
+ */
 public interface ReliabilityLayer extends ReadHandler {
 
+	/** Starts the reliability layer. */
 	void start();
 
+	/**
+	 * Stops the reliability layer. After this method returns, no more data
+	 * will be sent to lower layers, and any data received from lower layers
+	 * will be ignored.
+	 */
 	void stop();
 
+	/**
+	 * Returns an input stream for higher layers to read from the reliability
+	 * layer.
+	 */
 	InputStream getInputStream();
 
+	/**
+	 * Returns an output stream for higher layers to write to the reliability
+	 * layer.
+	 */
 	OutputStream getOutputStream();
 }
diff --git a/briar-api/src/net/sf/briar/api/reliability/ReliabilityLayerFactory.java b/briar-api/src/net/sf/briar/api/reliability/ReliabilityLayerFactory.java
index 96b4a51b406e8d3313106572e0dbf997059cdcbb..848e3e6b080a38e0fb914e7b1419e90bdd6cab27 100644
--- a/briar-api/src/net/sf/briar/api/reliability/ReliabilityLayerFactory.java
+++ b/briar-api/src/net/sf/briar/api/reliability/ReliabilityLayerFactory.java
@@ -2,5 +2,6 @@ package net.sf.briar.api.reliability;
 
 public interface ReliabilityLayerFactory {
 
+	/** Returns a reliability layer that writes to the given lower layer. */
 	ReliabilityLayer createReliabilityLayer(WriteHandler writeHandler);
 }