} else {
if (sipStack.isLoggingEnabled(LogWriter.TRACE_DEBUG)) {
sipStack.getStackLogger().logDebug(
"Dropping ACK - cannot find a transaction or dialog");
}
SIPServerTransaction ackTransaction = sipStack
.findTransactionPendingAck(sipRequest);
if (ackTransaction != null) {
if (sipStack.isLoggingEnabled(LogWriter.TRACE_DEBUG))
sipStack.getStackLogger().logDebug("Found Tx pending ACK");
try {