See my response to thread https://community.jboss.org/message/791782#791782.
Note that in AS 5, these parameters are configured in $JBOSS_HOME/server/$CONFIG/deploy/messaging/remoting-bisocket-service.xml.
And you can read more about configuration of the bisocket transport in the Remoting Guide: http://docs.jboss.org/jbossremoting/2.5.3.SP1/html/chapter-configuration.html#d0e2481. That's for Remoting version 2.5.3.SP1, which ships with AS 5.1.0.GA.
By the way, I changed the thread title because the original title was causing a problem with submitting a reply. Don't know why.