We have been using OpenJMS for sending messages and have found it to be great. 

However, one of the members of our team recently changed his router and is experiencing long delays in getting a Session. 

On most systems the line 

javax.jms.Session session = s_JmsConnection.createSession(false, javax.jms.Session.AUTO_ACKNOWLEDGE);

returns in about 4 seconds. 

For servers in a single location that are behind a new router, it consistently takes 189 seconds. 

The server is configured with only the TCP connector. 

<ServerConfiguration host="*.*.*.*" embeddedJNDI="true" />
  <TcpConfiguration port="3035" jndiPort="3035" />
    <Connector scheme="tcp">
        <ConnectionFactory name="ConnectionFactory" />

Its truly baffling how changing a router is causing this huge delay in getting a session. Any help is greatly appreciated.