Packet loss

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

System and method for sequencing packets for multiprocessor parallelization in a computer network system

Abstract: Network input processing is distributed to multiple CPUs on multiprocessor systems to improve network throughput and take advantage of MP scalability. Packets received on the network are distributed to N high priority threads, wherein N is the number of CPUs on the system. N queues are provided to which the incoming packets are distributed. When one of the queues is started, one of the threads is scheduled to process packets on this queue at any one of the CPUs that is availableat the time. When all of the packets on the queue are processed, the thread becomes dormant. Packets are distributed to one of the N queues by using a hashing function based on the source MAC address, source IP address, or the packet's source and destination TCP port number, or all or a combination of the foregoing. The hashing mechanism ensures that the sequence of packets within a given communication session will be preserved. Distribution is effected by the device drivers of the system. Parallelism is thereby increased on network I/O processing, eliminating CPU bottleneck for high speed network I/Os, thereby improving network performance

Insertion of network data checksums by a network adapter

Abstract: A system implements checksumming of a network packet to be sent over a network. A processor constructs the network packet within a main memory. The network packet is transferred from the main memory to a packet storage memory within a network adapter. During the transfer, the network adapter calculates a checksum for the network packet. The network adapter then inserts the checksum into the network packet within the packet storage memory. The network adapter then sends the network packet to the network. In order to calculate the checksum for the network packet, hardware within the network adapter "snoops" an internal bus within the network adapter as the network packet is transported to the packet storage memory. Also, a checksum header is prepended to the network packet which includes control information for checksumming. This control information includes, for example, an indication whether the network adapter is to calculate a checksum and a specification of what data in the network packet is to be checksummed. The control information may additionally include a location within network packet where the checksum is to be inserted.

Network Mobility Protocol for Vehicular Ad Hoc Networks

Abstract: The goal of the network mobility (NEMO) management is to effectively reduce the complexity of handoff procedure and keep the mobile devices connected to the Internet Vehicle is moving so fast that it may cause the handoff and packet loss problems Both of the problems will lower down the throughput of the network To overcome these problems, we propose a novel NEMO protocol for vehicular ad hoc network (VANET) In freeway, since every car is moving in a fixed direction with high moving speed, the car adopting our protocol can acquire IP address from the VANET through vehicle to vehicle communications The vehicle can rely on the assistance of the front vehicle to execute the pre-handoff procedure or it may acquire its new IP address through multi-hop relays from the car on the lanes of the same or opposite direction and thus reduces the handoff delay and maintain the connectivity to the Internet Simulation results have shown that the proposed scheme is able to reduce both handoff delay and packet loss rate

Flow control system and method

Abstract: A flow control system include a congestion detecting section and control section. The congestion detecting section detects congestion in a packet switching network. The control section is arranged in a transmitting node. When the congestion detecting section detects congestion, the control section calculates a new transmission packet rate. When the new transmission packet rate is smaller than a current transmission packet rate, the control section changes the current transmission packet rate to the new transmission packet rate after transmission of data to be transmitted to a receiving node. A flow control method is also disclosed.

Systems and methods for performing debugging operations on networks using a controller

Abstract: A controller implemented on computing equipment may control switches in a network. The controller may provide flow tables that implement network policies to the switches to control packet forwarding through the network. The controller may provide debug table entries to the switches for use in a debug table that is separate from the flow table. The debug table entries may match incoming network packets and increment corresponding counters on the switches. The controller may retrieve count information from the counters for performing debugging operations on the network. For example, the controller may identify conflicts between fields of a selected flow table entry, determine whether elephant packet flows are present between switches, determine whether desired load balancing is being performed, determine whether a network path has changed, determine whether packet loss has occurred, and/or determine whether network packets are taking undesired paths based on the retrieved count information.