If I preCalculate, the deliverLargeMessage will give up earlier even if you had already received credits during the deliverMessage Process. - before the ping changes, if you kept the channel used for a long time you would miss pings and pongs eventually, and that *was* a problem before. We would be sending packets to the client, as the client is sending credits back, and the old ping code would not work. Maybe we don' t need to preCalculate any more. The only thing I would be concerned is on the repplication. I don' t know if the replication credit would create any problems with synchronizing live and backup. I would need to evaluate it and test it. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4239129#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...