private void SIPCancelTransaction_TransactionRequestReceived(SIPEndPoint localSIPEndPoint, SIPEndPoint remoteEndPoint, SIPTransaction sipTransaction, SIPRequest sipRequest)
        {
            try
            {
                //logger.Debug("CANCEL request received, attempting to locate and cancel transaction.");

                //UASInviteTransaction originalTransaction = (UASInviteTransaction)GetTransaction(GetRequestTransactionId(sipRequest.Header.Via.TopViaHeader.Branch, SIPMethodsEnum.INVITE));

                SIPResponse cancelResponse;

                if (m_originalTransaction != null)
                {
                    //logger.Debug("Transaction found to cancel " + originalTransaction.TransactionId + " type " + originalTransaction.TransactionType + ".");
                    m_originalTransaction.CancelCall();
                    cancelResponse = GetCancelResponse(sipRequest, SIPResponseStatusCodesEnum.Ok);
                }
                else
                {
                    cancelResponse = GetCancelResponse(sipRequest, SIPResponseStatusCodesEnum.CallLegTransactionDoesNotExist);
                }

                //UpdateTransactionState(SIPTransactionStatesEnum.Completed);
                SendFinalResponse(cancelResponse);
            }
            catch (Exception excp)
            {
                logger.Error("Exception SIPCancelTransaction GotRequest. " + excp.Message);
            }
        }