diff --git a/api/net/sf/briar/api/db/DatabaseComponent.java b/api/net/sf/briar/api/db/DatabaseComponent.java
index 1e1402b1f1afd7c479ef30cd27f4b1222235e218..857e6c1e5eaf86d5367ebd113c705be3a59e4634 100644
--- a/api/net/sf/briar/api/db/DatabaseComponent.java
+++ b/api/net/sf/briar/api/db/DatabaseComponent.java
@@ -26,8 +26,8 @@ import net.sf.briar.api.protocol.writers.AckWriter;
 import net.sf.briar.api.protocol.writers.BatchWriter;
 import net.sf.briar.api.protocol.writers.OfferWriter;
 import net.sf.briar.api.protocol.writers.RequestWriter;
-import net.sf.briar.api.protocol.writers.SubscriptionWriter;
-import net.sf.briar.api.protocol.writers.TransportWriter;
+import net.sf.briar.api.protocol.writers.SubscriptionUpdateWriter;
+import net.sf.briar.api.protocol.writers.TransportUpdateWriter;
 import net.sf.briar.api.transport.ConnectionWindow;
 
 /**
@@ -102,12 +102,12 @@ public interface DatabaseComponent {
 	throws DbException, IOException;
 
 	/** Generates a subscription update for the given contact. */
-	void generateSubscriptionUpdate(ContactId c, SubscriptionWriter s) throws
-	DbException, IOException;
+	void generateSubscriptionUpdate(ContactId c, SubscriptionUpdateWriter s)
+	throws DbException, IOException;
 
 	/** Generates a transport update for the given contact. */
-	void generateTransportUpdate(ContactId c, TransportWriter t) throws
-	DbException, IOException;
+	void generateTransportUpdate(ContactId c, TransportUpdateWriter t)
+	throws DbException, IOException;
 
 	/** Returns the configuration for the given transport. */
 	TransportConfig getConfig(TransportId t) throws DbException;
diff --git a/api/net/sf/briar/api/protocol/writers/MessageEncoder.java b/api/net/sf/briar/api/protocol/MessageEncoder.java
similarity index 85%
rename from api/net/sf/briar/api/protocol/writers/MessageEncoder.java
rename to api/net/sf/briar/api/protocol/MessageEncoder.java
index bb144720efc2e189d805b1354e54eb73f97dc8b9..f587c0c1b20c63f73ebede14ce47eb4193b54746 100644
--- a/api/net/sf/briar/api/protocol/writers/MessageEncoder.java
+++ b/api/net/sf/briar/api/protocol/MessageEncoder.java
@@ -1,13 +1,9 @@
-package net.sf.briar.api.protocol.writers;
+package net.sf.briar.api.protocol;
 
 import java.io.IOException;
 import java.security.GeneralSecurityException;
 import java.security.PrivateKey;
 
-import net.sf.briar.api.protocol.Author;
-import net.sf.briar.api.protocol.Group;
-import net.sf.briar.api.protocol.Message;
-import net.sf.briar.api.protocol.MessageId;
 
 public interface MessageEncoder {
 
diff --git a/api/net/sf/briar/api/protocol/ProtocolConstants.java b/api/net/sf/briar/api/protocol/ProtocolConstants.java
index 29f31df89975b9698beedc2a1c06dd514578854c..7e23d247a0474010ab9a5aaba6c860f2a48168e1 100644
--- a/api/net/sf/briar/api/protocol/ProtocolConstants.java
+++ b/api/net/sf/briar/api/protocol/ProtocolConstants.java
@@ -12,10 +12,10 @@ public interface ProtocolConstants {
 	static final int MAX_PACKET_LENGTH =
 		TransportConstants.MIN_CONNECTION_LENGTH - 1024;
 
-	/** The maximum number of transport plugins a node may support. */
+	/** The maximum number of transports a node may support. */
 	static final int MAX_TRANSPORTS = 50;
 
-	/** The maximum number of properties per transport plugin. */
+	/** The maximum number of properties per transport. */
 	static final int MAX_PROPERTIES_PER_TRANSPORT = 100;
 
 	/** The maximum length of a property's key or value in UTF-8 bytes. */
@@ -27,7 +27,7 @@ public interface ProtocolConstants {
 	/** The maximum length of a group's name in UTF-8 bytes. */
 	static final int MAX_GROUP_NAME_LENGTH = 50;
 
-	/** The maximum length of a serialised public key in bytes. */
+	/** The maximum length of a public key in bytes. */
 	static final int MAX_PUBLIC_KEY_LENGTH = 100;
 
 	/** The maximum length of an author's name in UTF-8 bytes. */
diff --git a/api/net/sf/briar/api/protocol/writers/AuthorWriter.java b/api/net/sf/briar/api/protocol/writers/AuthorWriter.java
deleted file mode 100644
index 702b0963ced259889e1dd1f5757bb3232b4e35d4..0000000000000000000000000000000000000000
--- a/api/net/sf/briar/api/protocol/writers/AuthorWriter.java
+++ /dev/null
@@ -1,11 +0,0 @@
-package net.sf.briar.api.protocol.writers;
-
-import java.io.IOException;
-
-import net.sf.briar.api.protocol.Author;
-import net.sf.briar.api.serial.Writer;
-
-public interface AuthorWriter {
-
-	void writeAuthor(Writer w, Author a) throws IOException;
-}
diff --git a/api/net/sf/briar/api/protocol/writers/GroupWriter.java b/api/net/sf/briar/api/protocol/writers/GroupWriter.java
deleted file mode 100644
index 40d595b1a7aa77a9530757f73b704016d8ed0b03..0000000000000000000000000000000000000000
--- a/api/net/sf/briar/api/protocol/writers/GroupWriter.java
+++ /dev/null
@@ -1,11 +0,0 @@
-package net.sf.briar.api.protocol.writers;
-
-import java.io.IOException;
-
-import net.sf.briar.api.protocol.Group;
-import net.sf.briar.api.serial.Writer;
-
-public interface GroupWriter {
-
-	void writeGroup(Writer w, Group g) throws IOException;
-}
diff --git a/api/net/sf/briar/api/protocol/writers/ProtocolWriterFactory.java b/api/net/sf/briar/api/protocol/writers/ProtocolWriterFactory.java
index 480ac550b49c3bfeacd46dd9f733f4cc6bb10ce7..a0e88b4faad3249d360b46bd40f7930160b647db 100644
--- a/api/net/sf/briar/api/protocol/writers/ProtocolWriterFactory.java
+++ b/api/net/sf/briar/api/protocol/writers/ProtocolWriterFactory.java
@@ -12,7 +12,7 @@ public interface ProtocolWriterFactory {
 
 	RequestWriter createRequestWriter(OutputStream out);
 
-	SubscriptionWriter createSubscriptionWriter(OutputStream out);
+	SubscriptionUpdateWriter createSubscriptionUpdateWriter(OutputStream out);
 
-	TransportWriter createTransportWriter(OutputStream out);
+	TransportUpdateWriter createTransportUpdateWriter(OutputStream out);
 }
diff --git a/api/net/sf/briar/api/protocol/writers/SubscriptionWriter.java b/api/net/sf/briar/api/protocol/writers/SubscriptionUpdateWriter.java
similarity index 88%
rename from api/net/sf/briar/api/protocol/writers/SubscriptionWriter.java
rename to api/net/sf/briar/api/protocol/writers/SubscriptionUpdateWriter.java
index 2fd582caca7220a927db11756ae40446198b0048..87c0ae5cd7e658e60a614e0161cbe334c80e8cd5 100644
--- a/api/net/sf/briar/api/protocol/writers/SubscriptionWriter.java
+++ b/api/net/sf/briar/api/protocol/writers/SubscriptionUpdateWriter.java
@@ -6,7 +6,7 @@ import java.util.Map;
 import net.sf.briar.api.protocol.Group;
 
 /** An interface for creating a subscription update. */
-public interface SubscriptionWriter {
+public interface SubscriptionUpdateWriter {
 
 	/** Writes the contents of the update. */
 	void writeSubscriptions(Map<Group, Long> subs, long timestamp)
diff --git a/api/net/sf/briar/api/protocol/writers/TransportWriter.java b/api/net/sf/briar/api/protocol/writers/TransportUpdateWriter.java
similarity index 89%
rename from api/net/sf/briar/api/protocol/writers/TransportWriter.java
rename to api/net/sf/briar/api/protocol/writers/TransportUpdateWriter.java
index fb5a88bffe6f74fd77a3ba19908995eac1e11e7d..e3ea60838079576b370c81daede0fc64d00ebd38 100644
--- a/api/net/sf/briar/api/protocol/writers/TransportWriter.java
+++ b/api/net/sf/briar/api/protocol/writers/TransportUpdateWriter.java
@@ -6,7 +6,7 @@ import java.util.Collection;
 import net.sf.briar.api.protocol.Transport;
 
 /** An interface for creating a transport update. */
-public interface TransportWriter {
+public interface TransportUpdateWriter {
 
 	/** Writes the contents of the update. */
 	void writeTransports(Collection<Transport> transports, long timestamp)
diff --git a/components/net/sf/briar/db/DatabaseComponentImpl.java b/components/net/sf/briar/db/DatabaseComponentImpl.java
index 23b3ae4e14a89bbfdbca4f26307fe2b460339219..f3a82817887e877f3b639935e70174c81c0ca9e6 100644
--- a/components/net/sf/briar/db/DatabaseComponentImpl.java
+++ b/components/net/sf/briar/db/DatabaseComponentImpl.java
@@ -58,8 +58,8 @@ import net.sf.briar.api.protocol.writers.AckWriter;
 import net.sf.briar.api.protocol.writers.BatchWriter;
 import net.sf.briar.api.protocol.writers.OfferWriter;
 import net.sf.briar.api.protocol.writers.RequestWriter;
-import net.sf.briar.api.protocol.writers.SubscriptionWriter;
-import net.sf.briar.api.protocol.writers.TransportWriter;
+import net.sf.briar.api.protocol.writers.SubscriptionUpdateWriter;
+import net.sf.briar.api.protocol.writers.TransportUpdateWriter;
 import net.sf.briar.api.transport.ConnectionWindow;
 
 import com.google.inject.Inject;
@@ -602,8 +602,8 @@ DatabaseCleaner.Callback {
 		return sent;
 	}
 
-	public void generateSubscriptionUpdate(ContactId c, SubscriptionWriter s)
-	throws DbException, IOException {
+	public void generateSubscriptionUpdate(ContactId c,
+			SubscriptionUpdateWriter s) throws DbException, IOException {
 		Map<Group, Long> subs = null;
 		long timestamp = 0L;
 		contactLock.readLock().lock();
@@ -644,7 +644,7 @@ DatabaseCleaner.Callback {
 		return now - sent >= DatabaseConstants.MAX_UPDATE_INTERVAL;
 	}
 
-	public void generateTransportUpdate(ContactId c, TransportWriter t)
+	public void generateTransportUpdate(ContactId c, TransportUpdateWriter t)
 	throws DbException, IOException {
 		Collection<Transport> transports = null;
 		long timestamp = 0L;
diff --git a/components/net/sf/briar/protocol/MessageEncoderImpl.java b/components/net/sf/briar/protocol/MessageEncoderImpl.java
index 821e53016611497d6749a74ab12e4424bcd6e637..5d5d68dd4fb22ade8b3291fac4195944d3172831 100644
--- a/components/net/sf/briar/protocol/MessageEncoderImpl.java
+++ b/components/net/sf/briar/protocol/MessageEncoderImpl.java
@@ -14,12 +14,10 @@ import net.sf.briar.api.protocol.AuthorId;
 import net.sf.briar.api.protocol.Group;
 import net.sf.briar.api.protocol.GroupId;
 import net.sf.briar.api.protocol.Message;
+import net.sf.briar.api.protocol.MessageEncoder;
 import net.sf.briar.api.protocol.MessageId;
 import net.sf.briar.api.protocol.ProtocolConstants;
 import net.sf.briar.api.protocol.Types;
-import net.sf.briar.api.protocol.writers.AuthorWriter;
-import net.sf.briar.api.protocol.writers.GroupWriter;
-import net.sf.briar.api.protocol.writers.MessageEncoder;
 import net.sf.briar.api.serial.Consumer;
 import net.sf.briar.api.serial.Writer;
 import net.sf.briar.api.serial.WriterFactory;
@@ -32,19 +30,14 @@ class MessageEncoderImpl implements MessageEncoder {
 	private final SecureRandom random;
 	private final MessageDigest messageDigest;
 	private final WriterFactory writerFactory;
-	private final AuthorWriter authorWriter;
-	private final GroupWriter groupWriter;
 
 	@Inject
-	MessageEncoderImpl(CryptoComponent crypto, WriterFactory writerFactory,
-			AuthorWriter authorWriter, GroupWriter groupWriter) {
+	MessageEncoderImpl(CryptoComponent crypto, WriterFactory writerFactory) {
 		authorSignature = crypto.getSignature();
 		groupSignature = crypto.getSignature();
 		random = crypto.getSecureRandom();
 		messageDigest = crypto.getMessageDigest();
 		this.writerFactory = writerFactory;
-		this.authorWriter = authorWriter;
-		this.groupWriter = groupWriter;
 	}
 
 	public Message encodeMessage(MessageId parent, String subject, byte[] body)
@@ -111,9 +104,9 @@ class MessageEncoderImpl implements MessageEncoder {
 		if(parent == null) w.writeNull();
 		else w.writeBytes(parent.getBytes());
 		if(group == null) w.writeNull();
-		else groupWriter.writeGroup(w, group);
+		else writeGroup(w, group);
 		if(author == null) w.writeNull();
-		else authorWriter.writeAuthor(w, author);
+		else writeAuthor(w, author);
 		w.writeString(subject);
 		long timestamp = System.currentTimeMillis();
 		w.writeInt64(timestamp);
@@ -151,4 +144,18 @@ class MessageEncoderImpl implements MessageEncoder {
 		return new MessageImpl(id, parent, groupId, authorId, subject,
 				timestamp, raw, bodyStart, body.length);
 	}
+
+	private void writeGroup(Writer w, Group g) throws IOException {
+		w.writeUserDefinedId(Types.GROUP);
+		w.writeString(g.getName());
+		byte[] publicKey = g.getPublicKey();
+		if(publicKey == null) w.writeNull();
+		else w.writeBytes(publicKey);
+	}
+
+	private void writeAuthor(Writer w, Author a) throws IOException {
+		w.writeUserDefinedId(Types.AUTHOR);
+		w.writeString(a.getName());
+		w.writeBytes(a.getPublicKey());
+	}
 }
diff --git a/components/net/sf/briar/protocol/ProtocolModule.java b/components/net/sf/briar/protocol/ProtocolModule.java
index aa9c033f2554729565ed5b87971ab4ca843728aa..b19a08f865c598e6890d2c9ecc2d209a69809720 100644
--- a/components/net/sf/briar/protocol/ProtocolModule.java
+++ b/components/net/sf/briar/protocol/ProtocolModule.java
@@ -9,13 +9,13 @@ import net.sf.briar.api.protocol.BatchId;
 import net.sf.briar.api.protocol.Group;
 import net.sf.briar.api.protocol.GroupFactory;
 import net.sf.briar.api.protocol.Message;
+import net.sf.briar.api.protocol.MessageEncoder;
 import net.sf.briar.api.protocol.MessageId;
 import net.sf.briar.api.protocol.Offer;
 import net.sf.briar.api.protocol.ProtocolReaderFactory;
 import net.sf.briar.api.protocol.Request;
 import net.sf.briar.api.protocol.SubscriptionUpdate;
 import net.sf.briar.api.protocol.TransportUpdate;
-import net.sf.briar.api.protocol.writers.MessageEncoder;
 import net.sf.briar.api.serial.ObjectReader;
 
 import com.google.inject.AbstractModule;
diff --git a/components/net/sf/briar/protocol/writers/AuthorWriterImpl.java b/components/net/sf/briar/protocol/writers/AuthorWriterImpl.java
deleted file mode 100644
index eb1d16e90aee71a46f53db552cdcc3b4cc866410..0000000000000000000000000000000000000000
--- a/components/net/sf/briar/protocol/writers/AuthorWriterImpl.java
+++ /dev/null
@@ -1,17 +0,0 @@
-package net.sf.briar.protocol.writers;
-
-import java.io.IOException;
-
-import net.sf.briar.api.protocol.Author;
-import net.sf.briar.api.protocol.Types;
-import net.sf.briar.api.protocol.writers.AuthorWriter;
-import net.sf.briar.api.serial.Writer;
-
-class AuthorWriterImpl implements AuthorWriter {
-
-	public void writeAuthor(Writer w, Author a) throws IOException {
-		w.writeUserDefinedId(Types.AUTHOR);
-		w.writeString(a.getName());
-		w.writeBytes(a.getPublicKey());
-	}
-}
diff --git a/components/net/sf/briar/protocol/writers/GroupWriterImpl.java b/components/net/sf/briar/protocol/writers/GroupWriterImpl.java
deleted file mode 100644
index 44974a1f6044f121047582aefe23e55f94d5e854..0000000000000000000000000000000000000000
--- a/components/net/sf/briar/protocol/writers/GroupWriterImpl.java
+++ /dev/null
@@ -1,19 +0,0 @@
-package net.sf.briar.protocol.writers;
-
-import java.io.IOException;
-
-import net.sf.briar.api.protocol.Group;
-import net.sf.briar.api.protocol.Types;
-import net.sf.briar.api.protocol.writers.GroupWriter;
-import net.sf.briar.api.serial.Writer;
-
-class GroupWriterImpl implements GroupWriter {
-
-	public void writeGroup(Writer w, Group g) throws IOException {
-		w.writeUserDefinedId(Types.GROUP);
-		w.writeString(g.getName());
-		byte[] publicKey = g.getPublicKey();
-		if(publicKey == null) w.writeNull();
-		else w.writeBytes(publicKey);
-	}
-}
diff --git a/components/net/sf/briar/protocol/writers/ProtocolWriterFactoryImpl.java b/components/net/sf/briar/protocol/writers/ProtocolWriterFactoryImpl.java
index b0e36477993344b6b118ab78e82dbe272deca18d..ed6b55844824e765bd3ed7ab42105a218a30d888 100644
--- a/components/net/sf/briar/protocol/writers/ProtocolWriterFactoryImpl.java
+++ b/components/net/sf/briar/protocol/writers/ProtocolWriterFactoryImpl.java
@@ -9,8 +9,8 @@ import net.sf.briar.api.protocol.writers.BatchWriter;
 import net.sf.briar.api.protocol.writers.OfferWriter;
 import net.sf.briar.api.protocol.writers.ProtocolWriterFactory;
 import net.sf.briar.api.protocol.writers.RequestWriter;
-import net.sf.briar.api.protocol.writers.SubscriptionWriter;
-import net.sf.briar.api.protocol.writers.TransportWriter;
+import net.sf.briar.api.protocol.writers.SubscriptionUpdateWriter;
+import net.sf.briar.api.protocol.writers.TransportUpdateWriter;
 import net.sf.briar.api.serial.SerialComponent;
 import net.sf.briar.api.serial.WriterFactory;
 
@@ -46,11 +46,12 @@ class ProtocolWriterFactoryImpl implements ProtocolWriterFactory {
 		return new RequestWriterImpl(out, writerFactory);
 	}
 
-	public SubscriptionWriter createSubscriptionWriter(OutputStream out) {
-		return new SubscriptionWriterImpl(out, writerFactory);
+	public SubscriptionUpdateWriter createSubscriptionUpdateWriter(
+			OutputStream out) {
+		return new SubscriptionUpdateWriterImpl(out, writerFactory);
 	}
 
-	public TransportWriter createTransportWriter(OutputStream out) {
-		return new TransportWriterImpl(out, writerFactory);
+	public TransportUpdateWriter createTransportUpdateWriter(OutputStream out) {
+		return new TransportUpdateWriterImpl(out, writerFactory);
 	}
 }
diff --git a/components/net/sf/briar/protocol/writers/ProtocolWritersModule.java b/components/net/sf/briar/protocol/writers/ProtocolWritersModule.java
index 1afe708d9b259b0949706dfa78cc861480be314c..7e83b36b0511020ffe133de15e4f77347271c20a 100644
--- a/components/net/sf/briar/protocol/writers/ProtocolWritersModule.java
+++ b/components/net/sf/briar/protocol/writers/ProtocolWritersModule.java
@@ -1,7 +1,5 @@
 package net.sf.briar.protocol.writers;
 
-import net.sf.briar.api.protocol.writers.AuthorWriter;
-import net.sf.briar.api.protocol.writers.GroupWriter;
 import net.sf.briar.api.protocol.writers.ProtocolWriterFactory;
 
 import com.google.inject.AbstractModule;
@@ -10,8 +8,6 @@ public class ProtocolWritersModule extends AbstractModule {
 
 	@Override
 	protected void configure() {
-		bind(AuthorWriter.class).to(AuthorWriterImpl.class);
-		bind(GroupWriter.class).to(GroupWriterImpl.class);
 		bind(ProtocolWriterFactory.class).to(ProtocolWriterFactoryImpl.class);
 	}
 }
diff --git a/components/net/sf/briar/protocol/writers/SubscriptionWriterImpl.java b/components/net/sf/briar/protocol/writers/SubscriptionUpdateWriterImpl.java
similarity index 60%
rename from components/net/sf/briar/protocol/writers/SubscriptionWriterImpl.java
rename to components/net/sf/briar/protocol/writers/SubscriptionUpdateWriterImpl.java
index cf1d8ff60c50b109d4c9d2c217c9229529fef83d..1856d08e6f011ffd3372716dc6c2b13319dc7b1f 100644
--- a/components/net/sf/briar/protocol/writers/SubscriptionWriterImpl.java
+++ b/components/net/sf/briar/protocol/writers/SubscriptionUpdateWriterImpl.java
@@ -7,21 +7,19 @@ import java.util.Map.Entry;
 
 import net.sf.briar.api.protocol.Group;
 import net.sf.briar.api.protocol.Types;
-import net.sf.briar.api.protocol.writers.GroupWriter;
-import net.sf.briar.api.protocol.writers.SubscriptionWriter;
+import net.sf.briar.api.protocol.writers.SubscriptionUpdateWriter;
 import net.sf.briar.api.serial.Writer;
 import net.sf.briar.api.serial.WriterFactory;
 
-class SubscriptionWriterImpl implements SubscriptionWriter {
+class SubscriptionUpdateWriterImpl implements SubscriptionUpdateWriter {
 
 	private final OutputStream out;
 	private final Writer w;
-	private final GroupWriter groupWriter;
 
-	SubscriptionWriterImpl(OutputStream out, WriterFactory writerFactory) {
+	SubscriptionUpdateWriterImpl(OutputStream out,
+			WriterFactory writerFactory) {
 		this.out = out;
 		w = writerFactory.createWriter(out);
-		groupWriter = new GroupWriterImpl();
 	}
 
 	public void writeSubscriptions(Map<Group, Long> subs, long timestamp)
@@ -29,11 +27,19 @@ class SubscriptionWriterImpl implements SubscriptionWriter {
 		w.writeUserDefinedId(Types.SUBSCRIPTION_UPDATE);
 		w.writeMapStart();
 		for(Entry<Group, Long> e : subs.entrySet()) {
-			groupWriter.writeGroup(w, e.getKey());
+			writeGroup(w, e.getKey());
 			w.writeInt64(e.getValue());
 		}
 		w.writeMapEnd();
 		w.writeInt64(timestamp);
 		out.flush();
 	}
+
+	private void writeGroup(Writer w, Group g) throws IOException {
+		w.writeUserDefinedId(Types.GROUP);
+		w.writeString(g.getName());
+		byte[] publicKey = g.getPublicKey();
+		if(publicKey == null) w.writeNull();
+		else w.writeBytes(publicKey);
+	}
 }
diff --git a/components/net/sf/briar/protocol/writers/TransportWriterImpl.java b/components/net/sf/briar/protocol/writers/TransportUpdateWriterImpl.java
similarity index 80%
rename from components/net/sf/briar/protocol/writers/TransportWriterImpl.java
rename to components/net/sf/briar/protocol/writers/TransportUpdateWriterImpl.java
index aa58385e49bc285a7acfcc7f7beb34d118b8f34d..dad83683565cfa95b5612f13e8123c9f2dc910e5 100644
--- a/components/net/sf/briar/protocol/writers/TransportWriterImpl.java
+++ b/components/net/sf/briar/protocol/writers/TransportUpdateWriterImpl.java
@@ -6,16 +6,16 @@ import java.util.Collection;
 
 import net.sf.briar.api.protocol.Transport;
 import net.sf.briar.api.protocol.Types;
-import net.sf.briar.api.protocol.writers.TransportWriter;
+import net.sf.briar.api.protocol.writers.TransportUpdateWriter;
 import net.sf.briar.api.serial.Writer;
 import net.sf.briar.api.serial.WriterFactory;
 
-class TransportWriterImpl implements TransportWriter {
+class TransportUpdateWriterImpl implements TransportUpdateWriter {
 
 	private final OutputStream out;
 	private final Writer w;
 
-	TransportWriterImpl(OutputStream out, WriterFactory writerFactory) {
+	TransportUpdateWriterImpl(OutputStream out, WriterFactory writerFactory) {
 		this.out = out;
 		w = writerFactory.createWriter(out);
 	}
diff --git a/components/net/sf/briar/transport/batch/OutgoingBatchConnection.java b/components/net/sf/briar/transport/batch/OutgoingBatchConnection.java
index 59207076c3547c6d4b6acd6a4b9c5f4ffebdee0f..810a4e789933d0b01daf50d6fb5b8c00e11bf7c6 100644
--- a/components/net/sf/briar/transport/batch/OutgoingBatchConnection.java
+++ b/components/net/sf/briar/transport/batch/OutgoingBatchConnection.java
@@ -14,8 +14,8 @@ import net.sf.briar.api.protocol.TransportIndex;
 import net.sf.briar.api.protocol.writers.AckWriter;
 import net.sf.briar.api.protocol.writers.BatchWriter;
 import net.sf.briar.api.protocol.writers.ProtocolWriterFactory;
-import net.sf.briar.api.protocol.writers.SubscriptionWriter;
-import net.sf.briar.api.protocol.writers.TransportWriter;
+import net.sf.briar.api.protocol.writers.SubscriptionUpdateWriter;
+import net.sf.briar.api.protocol.writers.TransportUpdateWriter;
 import net.sf.briar.api.transport.BatchTransportWriter;
 import net.sf.briar.api.transport.ConnectionWriter;
 import net.sf.briar.api.transport.ConnectionWriterFactory;
@@ -56,13 +56,14 @@ class OutgoingBatchConnection {
 			long capacity = conn.getRemainingCapacity();
 			if(capacity < MAX_PACKET_LENGTH) throw new IOException();
 			// Write a transport update
-			TransportWriter t = protoFactory.createTransportWriter(out);
+			TransportUpdateWriter t =
+				protoFactory.createTransportUpdateWriter(out);
 			db.generateTransportUpdate(contactId, t);
 			// If there's space, write a subscription update
 			capacity = conn.getRemainingCapacity();
 			if(capacity >= MAX_PACKET_LENGTH) {
-				SubscriptionWriter s =
-					protoFactory.createSubscriptionWriter(out);
+				SubscriptionUpdateWriter s =
+					protoFactory.createSubscriptionUpdateWriter(out);
 				db.generateSubscriptionUpdate(contactId, s);
 			}
 			// Write acks until you can't write acks no more
diff --git a/components/net/sf/briar/transport/stream/StreamConnection.java b/components/net/sf/briar/transport/stream/StreamConnection.java
index 126e69c4b4ee000d7bc2205c5e276ae8591287f3..90d026b63b8f0edc5a3f4e6efa54d2ca46cac9b2 100644
--- a/components/net/sf/briar/transport/stream/StreamConnection.java
+++ b/components/net/sf/briar/transport/stream/StreamConnection.java
@@ -36,8 +36,8 @@ import net.sf.briar.api.protocol.writers.BatchWriter;
 import net.sf.briar.api.protocol.writers.OfferWriter;
 import net.sf.briar.api.protocol.writers.ProtocolWriterFactory;
 import net.sf.briar.api.protocol.writers.RequestWriter;
-import net.sf.briar.api.protocol.writers.SubscriptionWriter;
-import net.sf.briar.api.protocol.writers.TransportWriter;
+import net.sf.briar.api.protocol.writers.SubscriptionUpdateWriter;
+import net.sf.briar.api.protocol.writers.TransportUpdateWriter;
 import net.sf.briar.api.transport.ConnectionReader;
 import net.sf.briar.api.transport.ConnectionReaderFactory;
 import net.sf.briar.api.transport.ConnectionWriter;
@@ -194,13 +194,13 @@ abstract class StreamConnection implements DatabaseListener {
 			OfferWriter offerWriter = protoWriterFactory.createOfferWriter(out);
 			RequestWriter requestWriter =
 				protoWriterFactory.createRequestWriter(out);
-			SubscriptionWriter subscriptionWriter =
-				protoWriterFactory.createSubscriptionWriter(out);
-			TransportWriter transportWriter =
-				protoWriterFactory.createTransportWriter(out);
+			SubscriptionUpdateWriter subscriptionUpdateWriter =
+				protoWriterFactory.createSubscriptionUpdateWriter(out);
+			TransportUpdateWriter transportUpdateWriter =
+				protoWriterFactory.createTransportUpdateWriter(out);
 			// Send the initial packets: transports, subs, any waiting acks
-			sendTransports(transportWriter);
-			sendSubscriptions(subscriptionWriter);
+			sendTransportUpdate(transportUpdateWriter);
+			sendSubscriptionUpdate(subscriptionUpdateWriter);
 			sendAcks(ackWriter);
 			State state = State.SEND_OFFER;
 			// Main loop
@@ -234,10 +234,10 @@ abstract class StreamConnection implements DatabaseListener {
 						return;
 					}
 					if((flags & Flags.TRANSPORTS_UPDATED) != 0) {
-						sendTransports(transportWriter);
+						sendTransportUpdate(transportUpdateWriter);
 					}
 					if((flags & Flags.SUBSCRIPTIONS_UPDATED) != 0) {
-						sendSubscriptions(subscriptionWriter);
+						sendSubscriptionUpdate(subscriptionUpdateWriter);
 					}
 					if((flags & Flags.BATCH_RECEIVED) != 0) {
 						sendAcks(ackWriter);
@@ -274,10 +274,10 @@ abstract class StreamConnection implements DatabaseListener {
 						return;
 					}
 					if((flags & Flags.TRANSPORTS_UPDATED) != 0) {
-						sendTransports(transportWriter);
+						sendTransportUpdate(transportUpdateWriter);
 					}
 					if((flags & Flags.SUBSCRIPTIONS_UPDATED) != 0) {
-						sendSubscriptions(subscriptionWriter);
+						sendSubscriptionUpdate(subscriptionUpdateWriter);
 					}
 					if((flags & Flags.BATCH_RECEIVED) != 0) {
 						sendAcks(ackWriter);
@@ -305,10 +305,10 @@ abstract class StreamConnection implements DatabaseListener {
 						return;
 					}
 					if((flags & Flags.TRANSPORTS_UPDATED) != 0) {
-						sendTransports(transportWriter);
+						sendTransportUpdate(transportUpdateWriter);
 					}
 					if((flags & Flags.SUBSCRIPTIONS_UPDATED) != 0) {
-						sendSubscriptions(subscriptionWriter);
+						sendSubscriptionUpdate(subscriptionUpdateWriter);
 					}
 					if((flags & Flags.BATCH_RECEIVED) != 0) {
 						sendAcks(ackWriter);
@@ -388,13 +388,13 @@ abstract class StreamConnection implements DatabaseListener {
 		db.receiveOffer(contactId, o, r);
 	}
 
-	private void sendTransports(TransportWriter t) throws DbException,
-	IOException {
+	private void sendTransportUpdate(TransportUpdateWriter t)
+	throws DbException, IOException {
 		db.generateTransportUpdate(contactId, t);
 	}
 
-	private void sendSubscriptions(SubscriptionWriter s) throws DbException,
-	IOException {
+	private void sendSubscriptionUpdate(SubscriptionUpdateWriter s)
+	throws DbException, IOException {
 		db.generateSubscriptionUpdate(contactId, s);
 	}
 }
diff --git a/test/net/sf/briar/ProtocolIntegrationTest.java b/test/net/sf/briar/ProtocolIntegrationTest.java
index 9f47b2af6545392c20adf56bcb1919c90caf7285..262625603d1f57a9b724c144dd7c955739659796 100644
--- a/test/net/sf/briar/ProtocolIntegrationTest.java
+++ b/test/net/sf/briar/ProtocolIntegrationTest.java
@@ -24,6 +24,7 @@ import net.sf.briar.api.protocol.BatchId;
 import net.sf.briar.api.protocol.Group;
 import net.sf.briar.api.protocol.GroupFactory;
 import net.sf.briar.api.protocol.Message;
+import net.sf.briar.api.protocol.MessageEncoder;
 import net.sf.briar.api.protocol.MessageId;
 import net.sf.briar.api.protocol.Offer;
 import net.sf.briar.api.protocol.ProtocolReader;
@@ -37,12 +38,11 @@ import net.sf.briar.api.protocol.TransportUpdate;
 import net.sf.briar.api.protocol.UniqueId;
 import net.sf.briar.api.protocol.writers.AckWriter;
 import net.sf.briar.api.protocol.writers.BatchWriter;
-import net.sf.briar.api.protocol.writers.MessageEncoder;
 import net.sf.briar.api.protocol.writers.OfferWriter;
 import net.sf.briar.api.protocol.writers.ProtocolWriterFactory;
 import net.sf.briar.api.protocol.writers.RequestWriter;
-import net.sf.briar.api.protocol.writers.SubscriptionWriter;
-import net.sf.briar.api.protocol.writers.TransportWriter;
+import net.sf.briar.api.protocol.writers.SubscriptionUpdateWriter;
+import net.sf.briar.api.protocol.writers.TransportUpdateWriter;
 import net.sf.briar.api.transport.ConnectionReader;
 import net.sf.briar.api.transport.ConnectionReaderFactory;
 import net.sf.briar.api.transport.ConnectionWriter;
@@ -167,15 +167,16 @@ public class ProtocolIntegrationTest extends TestCase {
 		requested.set(3);
 		r.writeRequest(requested, 4);
 
-		SubscriptionWriter s =
-			protocolWriterFactory.createSubscriptionWriter(out1);
+		SubscriptionUpdateWriter s =
+			protocolWriterFactory.createSubscriptionUpdateWriter(out1);
 		// Use a LinkedHashMap for predictable iteration order
 		Map<Group, Long> subs = new LinkedHashMap<Group, Long>();
 		subs.put(group, 0L);
 		subs.put(group1, 0L);
 		s.writeSubscriptions(subs, timestamp);
 
-		TransportWriter t = protocolWriterFactory.createTransportWriter(out1);
+		TransportUpdateWriter t =
+			protocolWriterFactory.createTransportUpdateWriter(out1);
 		t.writeTransports(transports, timestamp);
 
 		out1.close();
diff --git a/test/net/sf/briar/db/DatabaseComponentTest.java b/test/net/sf/briar/db/DatabaseComponentTest.java
index 8cabf9a2c1b1b07c0c4547b2508c89d74c18cd47..cf68411585ed4f29b977d21b10cea5a4c99c4be6 100644
--- a/test/net/sf/briar/db/DatabaseComponentTest.java
+++ b/test/net/sf/briar/db/DatabaseComponentTest.java
@@ -40,8 +40,8 @@ import net.sf.briar.api.protocol.writers.AckWriter;
 import net.sf.briar.api.protocol.writers.BatchWriter;
 import net.sf.briar.api.protocol.writers.OfferWriter;
 import net.sf.briar.api.protocol.writers.RequestWriter;
-import net.sf.briar.api.protocol.writers.SubscriptionWriter;
-import net.sf.briar.api.protocol.writers.TransportWriter;
+import net.sf.briar.api.protocol.writers.SubscriptionUpdateWriter;
+import net.sf.briar.api.protocol.writers.TransportUpdateWriter;
 import net.sf.briar.api.transport.ConnectionWindow;
 
 import org.jmock.Expectations;
@@ -488,10 +488,10 @@ public abstract class DatabaseComponentTest extends TestCase {
 		final AckWriter ackWriter = context.mock(AckWriter.class);
 		final BatchWriter batchWriter = context.mock(BatchWriter.class);
 		final OfferWriter offerWriter = context.mock(OfferWriter.class);
-		final SubscriptionWriter subscriptionWriter =
-			context.mock(SubscriptionWriter.class);
-		final TransportWriter transportWriter =
-			context.mock(TransportWriter.class);
+		final SubscriptionUpdateWriter subscriptionUpdateWriter =
+			context.mock(SubscriptionUpdateWriter.class);
+		final TransportUpdateWriter transportUpdateWriter =
+			context.mock(TransportUpdateWriter.class);
 		final Ack ack = context.mock(Ack.class);
 		final Batch batch = context.mock(Batch.class);
 		final Offer offer = context.mock(Offer.class);
@@ -537,12 +537,12 @@ public abstract class DatabaseComponentTest extends TestCase {
 		} catch(NoSuchContactException expected) {}
 
 		try {
-			db.generateSubscriptionUpdate(contactId, subscriptionWriter);
+			db.generateSubscriptionUpdate(contactId, subscriptionUpdateWriter);
 			fail();
 		} catch(NoSuchContactException expected) {}
 
 		try {
-			db.generateTransportUpdate(contactId, transportWriter);
+			db.generateTransportUpdate(contactId, transportUpdateWriter);
 			fail();
 		} catch(NoSuchContactException expected) {}
 
@@ -771,8 +771,8 @@ public abstract class DatabaseComponentTest extends TestCase {
 		@SuppressWarnings("unchecked")
 		final Database<Object> database = context.mock(Database.class);
 		final DatabaseCleaner cleaner = context.mock(DatabaseCleaner.class);
-		final SubscriptionWriter subscriptionWriter =
-			context.mock(SubscriptionWriter.class);
+		final SubscriptionUpdateWriter subscriptionUpdateWriter =
+			context.mock(SubscriptionUpdateWriter.class);
 		context.checking(new Expectations() {{
 			allowing(database).startTransaction();
 			will(returnValue(txn));
@@ -787,7 +787,7 @@ public abstract class DatabaseComponentTest extends TestCase {
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, cleaner);
 
-		db.generateSubscriptionUpdate(contactId, subscriptionWriter);
+		db.generateSubscriptionUpdate(contactId, subscriptionUpdateWriter);
 
 		context.assertIsSatisfied();
 	}
@@ -802,8 +802,8 @@ public abstract class DatabaseComponentTest extends TestCase {
 		@SuppressWarnings("unchecked")
 		final Database<Object> database = context.mock(Database.class);
 		final DatabaseCleaner cleaner = context.mock(DatabaseCleaner.class);
-		final SubscriptionWriter subscriptionWriter =
-			context.mock(SubscriptionWriter.class);
+		final SubscriptionUpdateWriter subscriptionUpdateWriter =
+			context.mock(SubscriptionUpdateWriter.class);
 		context.checking(new Expectations() {{
 			allowing(database).startTransaction();
 			will(returnValue(txn));
@@ -821,13 +821,13 @@ public abstract class DatabaseComponentTest extends TestCase {
 			oneOf(database).setSubscriptionsSent(with(txn), with(contactId),
 					with(any(long.class)));
 			// Add the subscriptions to the writer
-			oneOf(subscriptionWriter).writeSubscriptions(
+			oneOf(subscriptionUpdateWriter).writeSubscriptions(
 					with(Collections.singletonMap(group, 0L)),
 					with(any(long.class)));
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, cleaner);
 
-		db.generateSubscriptionUpdate(contactId, subscriptionWriter);
+		db.generateSubscriptionUpdate(contactId, subscriptionUpdateWriter);
 
 		context.assertIsSatisfied();
 	}
@@ -839,8 +839,8 @@ public abstract class DatabaseComponentTest extends TestCase {
 		@SuppressWarnings("unchecked")
 		final Database<Object> database = context.mock(Database.class);
 		final DatabaseCleaner cleaner = context.mock(DatabaseCleaner.class);
-		final TransportWriter transportWriter =
-			context.mock(TransportWriter.class);
+		final TransportUpdateWriter transportUpdateWriter =
+			context.mock(TransportUpdateWriter.class);
 		context.checking(new Expectations() {{
 			allowing(database).startTransaction();
 			will(returnValue(txn));
@@ -855,7 +855,7 @@ public abstract class DatabaseComponentTest extends TestCase {
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, cleaner);
 
-		db.generateTransportUpdate(contactId, transportWriter);
+		db.generateTransportUpdate(contactId, transportUpdateWriter);
 
 		context.assertIsSatisfied();
 	}
@@ -870,8 +870,8 @@ public abstract class DatabaseComponentTest extends TestCase {
 		@SuppressWarnings("unchecked")
 		final Database<Object> database = context.mock(Database.class);
 		final DatabaseCleaner cleaner = context.mock(DatabaseCleaner.class);
-		final TransportWriter transportWriter =
-			context.mock(TransportWriter.class);
+		final TransportUpdateWriter transportUpdateWriter =
+			context.mock(TransportUpdateWriter.class);
 		context.checking(new Expectations() {{
 			allowing(database).startTransaction();
 			will(returnValue(txn));
@@ -889,12 +889,12 @@ public abstract class DatabaseComponentTest extends TestCase {
 			oneOf(database).setTransportsSent(with(txn), with(contactId),
 					with(any(long.class)));
 			// Add the properties to the writer
-			oneOf(transportWriter).writeTransports(with(transports),
+			oneOf(transportUpdateWriter).writeTransports(with(transports),
 					with(any(long.class)));
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, cleaner);
 
-		db.generateTransportUpdate(contactId, transportWriter);
+		db.generateTransportUpdate(contactId, transportUpdateWriter);
 
 		context.assertIsSatisfied();
 	}
diff --git a/test/net/sf/briar/protocol/ProtocolReadWriteTest.java b/test/net/sf/briar/protocol/ProtocolReadWriteTest.java
index 5efbfdc1aa6f471614be768e8f07c51f14ce8bc0..d196ab368f56b58c71f49b10f3d8545765dd1a15 100644
--- a/test/net/sf/briar/protocol/ProtocolReadWriteTest.java
+++ b/test/net/sf/briar/protocol/ProtocolReadWriteTest.java
@@ -15,6 +15,7 @@ import net.sf.briar.api.protocol.BatchId;
 import net.sf.briar.api.protocol.Group;
 import net.sf.briar.api.protocol.GroupFactory;
 import net.sf.briar.api.protocol.Message;
+import net.sf.briar.api.protocol.MessageEncoder;
 import net.sf.briar.api.protocol.Offer;
 import net.sf.briar.api.protocol.ProtocolReader;
 import net.sf.briar.api.protocol.ProtocolReaderFactory;
@@ -26,12 +27,11 @@ import net.sf.briar.api.protocol.TransportIndex;
 import net.sf.briar.api.protocol.TransportUpdate;
 import net.sf.briar.api.protocol.writers.AckWriter;
 import net.sf.briar.api.protocol.writers.BatchWriter;
-import net.sf.briar.api.protocol.writers.MessageEncoder;
 import net.sf.briar.api.protocol.writers.OfferWriter;
 import net.sf.briar.api.protocol.writers.ProtocolWriterFactory;
 import net.sf.briar.api.protocol.writers.RequestWriter;
-import net.sf.briar.api.protocol.writers.SubscriptionWriter;
-import net.sf.briar.api.protocol.writers.TransportWriter;
+import net.sf.briar.api.protocol.writers.SubscriptionUpdateWriter;
+import net.sf.briar.api.protocol.writers.TransportUpdateWriter;
 import net.sf.briar.crypto.CryptoModule;
 import net.sf.briar.protocol.writers.ProtocolWritersModule;
 import net.sf.briar.serial.SerialModule;
@@ -99,10 +99,12 @@ public class ProtocolReadWriteTest extends TestCase {
 		RequestWriter r = writerFactory.createRequestWriter(out);
 		r.writeRequest(bitSet, 10);
 
-		SubscriptionWriter s = writerFactory.createSubscriptionWriter(out);
+		SubscriptionUpdateWriter s =
+			writerFactory.createSubscriptionUpdateWriter(out);
 		s.writeSubscriptions(subscriptions, timestamp);
 
-		TransportWriter t = writerFactory.createTransportWriter(out);
+		TransportUpdateWriter t =
+			writerFactory.createTransportUpdateWriter(out);
 		t.writeTransports(transports, timestamp);
 
 		// Read
diff --git a/test/net/sf/briar/protocol/writers/ConstantsTest.java b/test/net/sf/briar/protocol/writers/ConstantsTest.java
index d158040b39435f3e1796c11502731bc5efa9c740..387cd6d1e6ed1011b64f1321dd15b403d5dad7aa 100644
--- a/test/net/sf/briar/protocol/writers/ConstantsTest.java
+++ b/test/net/sf/briar/protocol/writers/ConstantsTest.java
@@ -27,6 +27,7 @@ import net.sf.briar.api.protocol.BatchId;
 import net.sf.briar.api.protocol.Group;
 import net.sf.briar.api.protocol.GroupFactory;
 import net.sf.briar.api.protocol.Message;
+import net.sf.briar.api.protocol.MessageEncoder;
 import net.sf.briar.api.protocol.MessageId;
 import net.sf.briar.api.protocol.Transport;
 import net.sf.briar.api.protocol.TransportId;
@@ -34,10 +35,9 @@ import net.sf.briar.api.protocol.TransportIndex;
 import net.sf.briar.api.protocol.UniqueId;
 import net.sf.briar.api.protocol.writers.AckWriter;
 import net.sf.briar.api.protocol.writers.BatchWriter;
-import net.sf.briar.api.protocol.writers.MessageEncoder;
 import net.sf.briar.api.protocol.writers.OfferWriter;
-import net.sf.briar.api.protocol.writers.SubscriptionWriter;
-import net.sf.briar.api.protocol.writers.TransportWriter;
+import net.sf.briar.api.protocol.writers.SubscriptionUpdateWriter;
+import net.sf.briar.api.protocol.writers.TransportUpdateWriter;
 import net.sf.briar.api.serial.SerialComponent;
 import net.sf.briar.api.serial.WriterFactory;
 import net.sf.briar.crypto.CryptoModule;
@@ -61,8 +61,7 @@ public class ConstantsTest extends TestCase {
 	public ConstantsTest() throws Exception {
 		super();
 		Injector i = Guice.createInjector(new CryptoModule(),
-				new ProtocolModule(), new ProtocolWritersModule(),
-				new SerialModule());
+				new ProtocolModule(), new SerialModule());
 		writerFactory = i.getInstance(WriterFactory.class);
 		crypto = i.getInstance(CryptoComponent.class);
 		serial = i.getInstance(SerialComponent.class);
@@ -191,7 +190,8 @@ public class ConstantsTest extends TestCase {
 		// Add the subscriptions to an update
 		ByteArrayOutputStream out =
 			new ByteArrayOutputStream(MAX_PACKET_LENGTH);
-		SubscriptionWriter s = new SubscriptionWriterImpl(out, writerFactory);
+		SubscriptionUpdateWriter s =
+			new SubscriptionUpdateWriterImpl(out, writerFactory);
 		s.writeSubscriptions(subs, Long.MAX_VALUE);
 		// Check the size of the serialised update
 		assertTrue(out.size() > MAX_GROUPS *
@@ -218,7 +218,8 @@ public class ConstantsTest extends TestCase {
 		// Add the transports to an update
 		ByteArrayOutputStream out =
 			new ByteArrayOutputStream(MAX_PACKET_LENGTH);
-		TransportWriter t = new TransportWriterImpl(out, writerFactory);
+		TransportUpdateWriter t =
+			new TransportUpdateWriterImpl(out, writerFactory);
 		t.writeTransports(transports, Long.MAX_VALUE);
 		// Check the size of the serialised update
 		assertTrue(out.size() > MAX_TRANSPORTS * (UniqueId.LENGTH + 4 +
diff --git a/test/net/sf/briar/transport/batch/BatchConnectionReadWriteTest.java b/test/net/sf/briar/transport/batch/BatchConnectionReadWriteTest.java
index c3e17d8d31891fdc9fe7e5fa507dc49c3d05c820..74b739f89103d807ad02bb75c793a6552e36c97d 100644
--- a/test/net/sf/briar/transport/batch/BatchConnectionReadWriteTest.java
+++ b/test/net/sf/briar/transport/batch/BatchConnectionReadWriteTest.java
@@ -19,12 +19,12 @@ import net.sf.briar.api.db.event.DatabaseEvent;
 import net.sf.briar.api.db.event.DatabaseListener;
 import net.sf.briar.api.db.event.MessagesAddedEvent;
 import net.sf.briar.api.protocol.Message;
+import net.sf.briar.api.protocol.MessageEncoder;
 import net.sf.briar.api.protocol.ProtocolReaderFactory;
 import net.sf.briar.api.protocol.Transport;
 import net.sf.briar.api.protocol.TransportId;
 import net.sf.briar.api.protocol.TransportIndex;
 import net.sf.briar.api.protocol.TransportUpdate;
-import net.sf.briar.api.protocol.writers.MessageEncoder;
 import net.sf.briar.api.protocol.writers.ProtocolWriterFactory;
 import net.sf.briar.api.transport.BatchTransportReader;
 import net.sf.briar.api.transport.BatchTransportWriter;