JMS max-pool-size in JBoss-EAP-5

Issue

I see the following configuration in the file deploy\messaging\jms-ds.xml

   <tx-connection-factory>
      <jndi-name>JmsXA</jndi-name>
      <xa-transaction/>
      <rar-name>jms-ra.rar</rar-name>
      <connection-definition>org.jboss.resource.adapter.jms.JmsConnectionFactory</connection-definition>
      <config-property name="SessionDefaultType" type="java.lang.String">javax.jms.Topic</config-property>
      <config-property name="JmsProviderAdapterJNDI" type="java.lang.String">java:/DefaultJMSProvider</config-property>
      <max-pool-size>100</max-pool-size>
      <security-domain-and-application>JmsXARealm</security-domain-and-application>
      <depends>jboss.messaging:service=ServerPeer</depends>
   </tx-connection-factory>

What does the "max-pool-size" mean?

<max-pool-size>100</max-pool-size>

What should be the value here and how it relates to the JMS datasource which is used for persisting the messages ?
what should be then the in the datasource ?