odl details:
org.opendaylight.controller.version = 0.1
org.opendaylight.controller.build.scm.version = 34bd6d37787f85ec228bd0dc5c1ff399ebd649b1
org.opendaylight.controller.build.user = jenkins-controller
org.opendaylight.controller.build.workspace = **********
org.opendaylight.controller.build.timestamp = 1406126629215
org.opendaylight.controller.build.machine = **********

A while after the bgp connection is established and updates are sent, odl initiates new session. I suspect that the following ex exceptions may cause it.

2014-07-24 00:51:44.631 PDT [nettyThreadgroupModule$NioEventLoopGroupCloseable-7-1] WARN i.n.channel.DefaultChannelPipeline - An exceptionCaught() event was fired, and it reached at the tail of the pipeline. It usually means the last handler in the pipeline did not handle the exception.
java.lang.NullPointerException: null
at org.opendaylight.protocol.bgp.rib.impl.BGPSynchronization.updReceived(BGPSynchronization.java:90) ~[na:na]
at org.opendaylight.protocol.bgp.rib.impl.BGPSessionImpl.handleMessage(BGPSessionImpl.java:187) ~[na:na]
at org.opendaylight.protocol.bgp.rib.impl.BGPSessionImpl.handleMessage(BGPSessionImpl.java:49) ~[na:na]
at org.opendaylight.protocol.framework.AbstractProtocolSession.channelRead0(AbstractProtocolSession.java:46) ~[na:na]
at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:103) ~[bundlefile:4.0.19.Final]
at io.netty.channel.DefaultChannelHandlerContext.invokeChannelRead(DefaultChannelHandlerContext.java:341) [bundlefile:4.0.19.Final]
at io.netty.channel.DefaultChannelHandlerContext.fireChannelRead(DefaultChannelHandlerContext.java:327) [bundlefile:4.0.19.Final]
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:163) [bundlefile:4.0.19.Final]
at io.netty.channel.DefaultChannelHandlerContext.invokeChannelRead(DefaultChannelHandlerContext.java:341) [bundlefile:4.0.19.Final]
at io.netty.channel.DefaultChannelHandlerContext.fireChannelRead(DefaultChannelHandlerContext.java:327) [bundlefile:4.0.19.Final]
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:163) [bundlefile:4.0.19.Final]
at io.netty.channel.DefaultChannelHandlerContext.invokeChannelRead(DefaultChannelHandlerContext.java:341) [bundlefile:4.0.19.Final]
at io.netty.channel.DefaultChannelHandlerContext.fireChannelRead(DefaultChannelHandlerContext.java:327) [bundlefile:4.0.19.Final]
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:785) [bundlefile:4.0.19.Final]
at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:126) [bundlefile:4.0.19.Final]
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:507) [bundlefile:4.0.19.Final]
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:464) [bundlefile:4.0.19.Final]
at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:378) [bundlefile:4.0.19.Final]
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:350) [bundlefile:4.0.19.Final]
at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:116) [bundlefile:4.0.19.Final]
at java.lang.Thread.run(Unknown Source) [na:1.7.0_55]

After commenting out the config part
<advertized-table>
<type xmlns:prefix="urn:opendaylight:params:xml:ns:yang:controller:bgp:rib:impl">prefix:bgp-table-type</type>
<name>ipv6-unicast</name>
</advertized-table>

i am getting
2014-07-24 01:18:32.395 PDT [nettyThreadgroupModule$NioEventLoopGroupCloseable-7-7] WARN i.n.channel.DefaultChannelPipeline - An exceptionCaught() event was fired, and it reached at the tail of the pipeline. It usually means the last handler in the pipeline did not handle the exception.
java.lang.NullPointerException: null
at org.opendaylight.protocol.bgp.rib.impl.BGPSynchronization.updReceived(BGPSynchronization.java:90) ~[na:na]
at org.opendaylight.protocol.bgp.rib.impl.BGPSessionImpl.handleMessage(BGPSessionImpl.java:187) ~[na:na]
at org.opendaylight.protocol.bgp.rib.impl.BGPSessionImpl.handleMessage(BGPSessionImpl.java:49) ~[na:na]
at org.opendaylight.protocol.framework.AbstractProtocolSession.channelRead0(AbstractProtocolSession.java:46) ~[na:na]
at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:103) ~[bundlefile:4.0.19.Final]
at io.netty.channel.DefaultChannelHandlerContext.invokeChannelRead(DefaultChannelHandlerContext.java:341) [bundlefile:4.0.19.Final]
at io.netty.channel.DefaultChannelHandlerContext.fireChannelRead(DefaultChannelHandlerContext.java:327) [bundlefile:4.0.19.Final]
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:163) [bundlefile:4.0.19.Final]
at io.netty.channel.DefaultChannelHandlerContext.invokeChannelRead(DefaultChannelHandlerContext.java:341) [bundlefile:4.0.19.Final]
at io.netty.channel.DefaultChannelHandlerContext.fireChannelRead(DefaultChannelHandlerContext.java:327) [bundlefile:4.0.19.Final]
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:163) [bundlefile:4.0.19.Final]
at io.netty.channel.DefaultChannelHandlerContext.invokeChannelRead(DefaultChannelHandlerContext.java:341) [bundlefile:4.0.19.Final]
at io.netty.channel.DefaultChannelHandlerContext.fireChannelRead(DefaultChannelHandlerContext.java:327) [bundlefile:4.0.19.Final]
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:785) [bundlefile:4.0.19.Final]
at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:126) [bundlefile:4.0.19.Final]
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:507) [bundlefile:4.0.19.Final]
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:464) [bundlefile:4.0.19.Final]
at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:378) [bundlefile:4.0.19.Final]
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:350) [bundlefile:4.0.19.Final]
at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:116) [bundlefile:4.0.19.Final]
at java.lang.Thread.run(Unknown Source) [na:1.7.0_55]

odl log and wireshark trace in attachment