When we try out the VTN Example socumented in thie page (https://wiki.opendaylight.org/view/OpenDaylight_Virtual_Tenant_Network_(VTN):VTN_Manager:Release/Lithium/VTN/HowTos/How_to_configure_L2_network_with_VTN_virtualization) . We observe the following error in our karaf .log

ation - 0.4.0.SNAPSHOT | Routing table has been updated.
2015-11-10 08:37:26,054 | WARN | entLoopGroup-7-2 | ResponseExpectedRpcListener | 146 - org.opendaylight.openflowjava.openflow-protocol-impl - 0.7.0.SNAPSHOT | Request for RpcResultKey [xid=3235, outputClazz=org.opendaylight.yang.gen.v1.urn.opendaylight.openflow.protocol.rev130731.BarrierOutput] did not receive a response
2015-11-10 08:37:26,055 | WARN | entLoopGroup-7-2 | ResponseExpectedRpcListener | 146 - org.opendaylight.openflowjava.openflow-protocol-impl - 0.7.0.SNAPSHOT | Request for RpcResultKey [xid=3460, outputClazz=org.opendaylight.yang.gen.v1.urn.opendaylight.openflow.protocol.rev130731.BarrierOutput] did not receive a response
2015-11-10 08:37:26,056 | WARN | entLoopGroup-7-1 | ResponseExpectedRpcListener | 146 - org.opendaylight.openflowjava.openflow-protocol-impl - 0.7.0.SNAPSHOT | Request for RpcResultKey [xid=3235, outputClazz=org.opendaylight.yang.gen.v1.urn.opendaylight.openflow.protocol.rev130731.BarrierOutput] did not receive a response
2015-11-10 08:37:26,060 | ERROR | TN Flow Thread-0 | FlowRemoveContext | 311 - org.opendaylight.vtn.manager.implementation - 0.4.0.SNAPSHOT | remove-flow: RPC returned error: errors=[RpcError [message=barrier sending failed, severity=WARNING, errorType=RPC, tag=TIMOUT, applicationTag=OPENFLOW_PLUGIN, info=switch failed to respond on barrier request, barrier.xid = 3235, cause=null], RpcError [message=check switch connection, severity=ERROR, errorType=RPC, tag=OPENFLOW, applicationTag=OPENFLOW_LIBRARY, info=barrier-input sending failed, cause=java.util.concurrent.TimeoutException: Request timed out]]
java.util.concurrent.TimeoutException: Request timed out
at org.opendaylight.openflowjava.protocol.impl.core.connection.ResponseExpectedRpcListener.discard(ResponseExpectedRpcListener.java:33)[146:org.opendaylight.openflowjava.openflow-protocol-impl:0.7.0.SNAPSHOT]
at org.opendaylight.openflowjava.protocol.impl.core.connection.ConnectionAdapterImpl$1.onRemoval(ConnectionAdapterImpl.java:105)[146:org.opendaylight.openflowjava.openflow-protocol-impl:0.7.0.SNAPSHOT]
at com.google.common.cache.LocalCache.processPendingNotifications(LocalCache.java:1956)[39:com.google.guava:18.0.0]
at com.google.common.cache.LocalCache$Segment.runUnlockedCleanup(LocalCache.java:3460)[39:com.google.guava:18.0.0]
at com.google.common.cache.LocalCache$Segment.postWriteCleanup(LocalCache.java:3436)[39:com.google.guava:18.0.0]
at com.google.common.cache.LocalCache$Segment.put(LocalCache.java:2891)[39:com.google.guava:18.0.0]
at com.google.common.cache.LocalCache.put(LocalCache.java:4149)[39:com.google.guava:18.0.0]
at com.google.common.cache.LocalCache$LocalManualCache.put(LocalCache.java:4754)[39:com.google.guava:18.0.0]
at org.opendaylight.openflowjava.protocol.impl.core.connection.ResponseExpectedRpcListener.operationSuccessful(ResponseExpectedRpcListener.java:44)[146:org.opendaylight.openflowjava.openflow-protocol-impl:0.7.0.SNAPSHOT]
at org.opendaylight.openflowjava.protocol.impl.core.connection.AbstractRpcListener.operationComplete(AbstractRpcListener.java:63)[146:org.opendaylight.openflowjava.openflow-protocol-impl:0.7.0.SNAPSHOT]
at io.netty.util.concurrent.DefaultPromise.notifyListener0(DefaultPromise.java:680)[99:io.netty.common:4.0.30.Final]
at io.netty.util.concurrent.DefaultPromise.notifyListeners(DefaultPromise.java:567)[99:io.netty.common:4.0.30.Final]
at io.netty.util.concurrent.DefaultPromise.trySuccess(DefaultPromise.java:406)[99:io.netty.common:4.0.30.Final]
at io.netty.channel.DefaultChannelPromise.trySuccess(DefaultChannelPromise.java:82)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.ChannelOutboundBuffer.safeSuccess(ChannelOutboundBuffer.java:672)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.ChannelOutboundBuffer.remove(ChannelOutboundBuffer.java:262)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.ChannelOutboundBuffer.removeBytes(ChannelOutboundBuffer.java:342)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.socket.nio.NioSocketChannel.doWrite(NioSocketChannel.java:318)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.AbstractChannel$AbstractUnsafe.flush0(AbstractChannel.java:761)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.flush0(AbstractNioChannel.java:311)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.AbstractChannel$AbstractUnsafe.flush(AbstractChannel.java:729)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.DefaultChannelPipeline$HeadContext.flush(DefaultChannelPipeline.java:1127)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeFlush(AbstractChannelHandlerContext.java:663)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.AbstractChannelHandlerContext.flush(AbstractChannelHandlerContext.java:644)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.ChannelOutboundHandlerAdapter.flush(ChannelOutboundHandlerAdapter.java:115)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeFlush(AbstractChannelHandlerContext.java:663)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.AbstractChannelHandlerContext.flush(AbstractChannelHandlerContext.java:644)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.DefaultChannelPipeline.flush(DefaultChannelPipeline.java:897)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.AbstractChannel.flush(AbstractChannel.java:192)[98:io.netty.transport:4.0.30.Final]
at org.opendaylight.openflowjava.protocol.impl.core.connection.ChannelOutboundQueue.flush(ChannelOutboundQueue.java:212)[146:org.opendaylight.openflowjava.openflow-protocol-impl:0.7.0.SNAPSHOT]
at org.opendaylight.openflowjava.protocol.impl.core.connection.ChannelOutboundQueue.access$000(ChannelOutboundQueue.java:37)[146:org.opendaylight.openflowjava.openflow-protocol-impl:0.7.0.SNAPSHOT]
at org.opendaylight.openflowjava.protocol.impl.core.connection.ChannelOutboundQueue$1.run(ChannelOutboundQueue.java:81)[146:org.opendaylight.openflowjava.openflow-protocol-impl:0.7.0.SNAPSHOT]
at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:327)[99:io.netty.common:4.0.30.Final]
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:350)[98:io.netty.transport:4.0.30.Final]
at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:110)[99:io.netty.common:4.0.30.Final]
at io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:137)[99:io.netty.common:4.0.30.Final]
at java.lang.Thread.run(Thread.java:745)[:1.8.0_65]
2015-11-10 08:37:26,062 | ERROR | TN Flow Thread-0 | FlowRemoveContext | 311 - org.opendaylight.vtn.manager.implementation - 0.4.0.SNAPSHOT | remove-flow: RPC returned error: errors=[RpcError [message=barrier sending failed, severity=WARNING, errorType=RPC, tag=TIMOUT, applicationTag=OPENFLOW_PLUGIN, info=switch failed to respond on barrier request, barrier.xid = 3460, cause=null], RpcError [message=check switch connection, severity=ERROR, errorType=RPC, tag=OPENFLOW, applicationTag=OPENFLOW_LIBRARY, info=barrier-input sending failed, cause=java.util.concurrent.TimeoutException: Request timed out]]
java.util.concurrent.TimeoutException: Request timed out
at org.opendaylight.openflowjava.protocol.impl.core.connection.ResponseExpectedRpcListener.discard(ResponseExpectedRpcListener.java:33)[146:org.opendaylight.openflowjava.openflow-protocol-impl:0.7.0.SNAPSHOT]
at org.opendaylight.openflowjava.protocol.impl.core.connection.ConnectionAdapterImpl$1.onRemoval(ConnectionAdapterImpl.java:105)[146:org.opendaylight.openflowjava.openflow-protocol-impl:0.7.0.SNAPSHOT]
at com.google.common.cache.LocalCache.processPendingNotifications(LocalCache.java:1956)[39:com.google.guava:18.0.0]
at com.google.common.cache.LocalCache$Segment.runUnlockedCleanup(LocalCache.java:3460)[39:com.google.guava:18.0.0]
at com.google.common.cache.LocalCache$Segment.postWriteCleanup(LocalCache.java:3436)[39:com.google.guava:18.0.0]
at com.google.common.cache.LocalCache$Segment.put(LocalCache.java:2891)[39:com.google.guava:18.0.0]
at com.google.common.cache.LocalCache.put(LocalCache.java:4149)[39:com.google.guava:18.0.0]
at com.google.common.cache.LocalCache$LocalManualCache.put(LocalCache.java:4754)[39:com.google.guava:18.0.0]
at org.opendaylight.openflowjava.protocol.impl.core.connection.ResponseExpectedRpcListener.operationSuccessful(ResponseExpectedRpcListener.java:44)[146:org.opendaylight.openflowjava.openflow-protocol-impl:0.7.0.SNAPSHOT]
at org.opendaylight.openflowjava.protocol.impl.core.connection.AbstractRpcListener.operationComplete(AbstractRpcListener.java:63)[146:org.opendaylight.openflowjava.openflow-protocol-impl:0.7.0.SNAPSHOT]
at io.netty.util.concurrent.DefaultPromise.notifyListener0(DefaultPromise.java:680)[99:io.netty.common:4.0.30.Final]
at io.netty.util.concurrent.DefaultPromise.notifyListeners(DefaultPromise.java:567)[99:io.netty.common:4.0.30.Final]
at io.netty.util.concurrent.DefaultPromise.trySuccess(DefaultPromise.java:406)[99:io.netty.common:4.0.30.Final]
at io.netty.channel.DefaultChannelPromise.trySuccess(DefaultChannelPromise.java:82)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.ChannelOutboundBuffer.safeSuccess(ChannelOutboundBuffer.java:672)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.ChannelOutboundBuffer.remove(ChannelOutboundBuffer.java:262)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.ChannelOutboundBuffer.removeBytes(ChannelOutboundBuffer.java:342)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.socket.nio.NioSocketChannel.doWrite(NioSocketChannel.java:318)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.AbstractChannel$AbstractUnsafe.flush0(AbstractChannel.java:761)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.flush0(AbstractNioChannel.java:311)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.AbstractChannel$AbstractUnsafe.flush(AbstractChannel.java:729)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.DefaultChannelPipeline$HeadContext.flush(DefaultChannelPipeline.java:1127)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeFlush(AbstractChannelHandlerContext.java:663)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.AbstractChannelHandlerContext.flush(AbstractChannelHandlerContext.java:644)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.ChannelOutboundHandlerAdapter.flush(ChannelOutboundHandlerAdapter.java:115)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeFlush(AbstractChannelHandlerContext.java:663)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.AbstractChannelHandlerContext.flush(AbstractChannelHandlerContext.java:644)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.DefaultChannelPipeline.flush(DefaultChannelPipeline.java:897)[98:io.netty.transport:4.0.30.Final]
at io.netty.channel.AbstractChannel.flush(AbstractChannel.java:192)[98:io.netty.transport:4.0.30.Final]
at org.opendaylight.openflowjava.protocol.impl.core.connection.ChannelOutboundQueue.flush(ChannelOutboundQueue.java:212)[146:org.opendaylight.openflowjava.openflow-protocol-impl:0.7.0.SNAPSHOT]
at org.opendaylight.openflowjava.protocol.impl.core.connection.ChannelOutboundQueue.access$000(ChannelOutboundQueue.java:37)[146:org.opendaylight.openflowjava.openflow-protocol-impl:0.7.0.SNAPSHOT]
at org.opendaylight.openflowjava.protocol.impl.core.connection.ChannelOutboundQueue$1.run(ChannelOutboundQueue.java:81)[146:org.opendaylight.openflowjava.openflow-protocol-impl:0.7.0.SNAPSHOT]
at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:327)[99:io.netty.common:4.0.30.Final]
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:350)[98:io.netty.transport:4.0.30.Final]
at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:110)[99:io.netty.common:4.0.30.Final]
at io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:137)[99:io.netty.common:4.0.30.Final]
at java.lang.Thread.run(Thread.java:745)[:1.8.0_65]
2015-11-10 08:37:26,309 | INFO | ult-dispatcher-5 | VTNInventoryManager | 311 - org.opendaylight.vtn.manager.implementation - 0.4.0.SNAPSHOT | Port has been removed: {id=openflow:2:1