Packet loss

About: Packet loss is a research topic. Over the lifetime, 21235 publications have been published within this topic receiving 302453 citations.

Enhancement of explicit congestion notification (ecn) for wireless network applications

Abstract: A new and improved Explicit Congestion Notification (ECN) mechanism, and associated method, for wireless and/or mobile network applications to avoid network congestion in a TCP/IP packet-switched network. A method of avoiding congestion in such a network comprises the steps of: transmitting, at a source node, data packets to a destination node, via at least an intermediate mode; determining, at the intermediate node, if an incipient congestion is encountered, and if the incipient congestion is encountered, setting a Congestion Experienced (CE) flag in each data packet which indicates the incipient congestion to notify the congestion to the destination node; receiving, at the destination node, a CE data packet, setting an Explicit Congestion Notification-Echo (ECN-Echo) flag in an acknowledgement (ACK) packet subsequent to the CE data packet received, and sending an ECH-Echo ACK packet back to the source node to inform that the congestion was encountered in the network on the path from the source node to the destination node; upon receipt of the ECN-Echo ACK packet, reducing, at the source node, a congestion window and a transmission rate to avoid the congestion, and determining if a packet loss is due to congestion or due to a transmission error, when the incipient congestion is still encountered in the network; if the packet loss is due to congestion, retransmitting, at the source node, only a lost packet to the destination node, via the intermediate node; and if the packet loss is due to the transmission error, re-transmitting, at the source node, the lost packet to the destination node, via the intermediate node, while increasing a round-trip timeout (RTO) but maintaining the same congestion window in order to improve the throughput of connection.

Internet of Things application layer protocol analysis over error and delay prone links

Abstract: Internet of Things (IoT) application layer protocols are gaining popularity in a wide range of scenarios, where low-cost, low-power or resource constrained devices are present. The most diffused protocols are the Constrained Application Protocol (CoAP) and MQTT. In order to ensure message delivery, CoAP features a retransmission mechanism based on exponential back-off and a finite number of retransmissions, while MQTT relies on TCP. In remote areas lacking fixed terrestrial network infrastructure, the only available Internet access technology is often represented by wireless or satellite links, usually affected by losses and significant delay. At this time, there is no information about MQTT and CoAP performance over high delay links in the literature. The goal of this paper is to provide a quantitative performance analysis of the mentioned IoT protocols over various conditions of offered traffic, packet loss probability and delay. Our findings show that, with default protocol parameters, MQTT offers better performance in terms of throughput in any of the considered scenarios. As far as latency is concerned, CoAP slightly outperforms MQTT in case of low offered traffic, low loss probability and high delay. We suggest to tune CoAP parameters in order to cope with high traffic and high loss probability: the new parameters result in improved latency and throughput in those conditions.

System and method for streaming multimedia over packet networks

Abstract: A data transmission method and protocol includes progressive coding of a data set into time stamped data packets. The packets are ordered in importance, with some packets being more critical to received data quality than other packets from the same source. If packets are delayed in transit from a source to a receiver, packets of lesser importance are discarded after a set time, a transmission and decoding of a second set of time critical data begins.

Forwarding multi-destination packets in a network with virtual port channels

Abstract: In one embodiment, a method includes receiving a multi-destination packet at a switch in communication with a plurality of servers through a network device, identifying a port receiving the multi-destination packet at the switch or a forwarding topology for the multi-destination packet, selecting a bit value based on the identified port or forwarding topology, inserting the bit value into a field in a virtual network tag in the multi-destination packet, and forwarding the multi-destination packet with the virtual network tag to the network device. The network device is configured to forward the multi-destination packet to one or more of the servers based on the bit value in the multi-destination packet. An apparatus for forwarding multi-destination packets is also disclosed.

Scheduling packets for Event-triggered control

Abstract: For a single control loop with communication rate constraints, Event-triggered control often outperforms periodic control. When multiple loops are being controlled over a shared contention-based medium, however, the advantage of event-triggered policies is less well understood. In this paper, we consider event-triggered impulse control under lossy communication. The sampling events are determined by level crossings of the plant output. It is shown how a stochastic control criterion depends on the level thresholds and the packet loss probability for a class of integrator plants. For multiple control loops, this result is used to derive a design guideline on how to assign the levels that lead to optimal use of the available communication resources. It is shown that the structure of the event generator depends critically on the loss probability.