while (1) {
    warn "Waiting for PDU";
    $pdu = $smpp->read_pdu() or die "$$: PDU not read. Closing connection";
    print "Received #$pdu->{seq} $pdu->{cmd}:". Net::SMPP::pdu_tab->{$pdu->{cmd}}{cmd} ."\n"
	;
    warn Dumper($pdu) if $trace;

    if (defined reply_tab->{$pdu->{cmd}}) {
	&{reply_tab->{$pdu->{cmd}}{reply}}($c, $pdu);
	warn "Replied";
    } else {
	warn "Don't know to reply to $pdu->{cmd}";
	sleep 1;
    }
}