Hello all, I have a classical receive handling structure for an asynchronous UDP socket: void receiver::receive(){ mySocket->async_receive_from( boost::asio::buffer(input, maxInputLength), senderEndpoint, boost::bind(&receiver::handleReceiveFrom, this, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred)); } void receiver::handleReceiveFrom(const boost::system::error_code &error, size_t bytes_recvd) { // SPECIFIC CODE HERE AND FINAK CALL OF RECEIVE FUNCTION this->receive(); } Besides this my app works with several realtime threads I have assigned maximum priority to via: pthread_t threadID = (pthread_t) sendThread.native_handle(); struct sched_param param; int policy = SCHED_FIFO; int max = sched_get_priority_max(policy); param.sched_priority = max; pthread_setschedparam(threadID, policy, ¶m); Now I wonder in how far these realtime threads can have an impact on the performance of my receiver process: So far I assumed that the receiver handle code is executed immediately when a packet arrives at the NIC but I am not sure if other realtime threads might possibly delay this process when scheduled first. In other words: If we think of the receiver handling process as a thread that is triggered by incoming packets does this thread also have realtime capabilities that can suffer from competing processes ? Thanks in advance for clarification, best Alex -- http://www.carot.de Email : Alexander@Carot.de Tel.: +49 (0)177 5719797