Abstract: A method of managing a packet administration map for data packets to be received via a network. A receiver in the network monitors sequence numbers and stores missing sequence numbers within an internal data structure, called a packet administration map. A reversed keying is used which means that the upper limit of the range of contiguous missing data packets is used as the key entry in the administration map.

Abstract: The invention relates to a method for transporting data over a data connection between a sending network component and a receiving network component via a network. The method solves a problem with the reliable data transport protocol according to which a number of data transport packets will be acknowledged in regular time intervals. When such an acknowledge message is lost, the sending network component will have to keep the data for the purpose of retransmission and cannot free its sending buffer. The invention proposes to repeat such an acknowledge message as a precaution for the case that it gets lost after a short time. The time for repeating is set to be less than an RTT (round trip time for the connection). The solution disregards the fact that no statement about the reception of the acknowledge message can get back to the receiver before the RTT has elapsed.

Abstract: A method and apparatus for file access in a storage access network (SAN) wherein a portion of a first file is accessed and an access rate computed based on time and amount of data accessed. If the computed access rate is less than an expected rate, a problem is identified and analysis performed. A first analysis accesses the first file through a second link to determine if the link is the problem. If the first file is accessed at an expected rate, the first link is identified as the problem and the file is accessed through an alternate link. A second analysis accesses a second file through the first link. If the second file is accessed at an expected rate, the first file is identified as the problem and the second file is accessed through the first link.

Abstract: The invention relates to a method for managing a data connection between a sending network component and a receiving network component via a network, and a network component, the method comprising the following steps: sending an initiating message to the receiving network component by the sending network component, to initiate a data connection between the sending network component and the receiving network component; receiving the initiating message by the receiving network component; sending further messages to the receiving network component by the sending network component; receiving the further messages by the receiving network component; calculating a transmission delay for at least one of the further messages received by the receiving network component; estimating optimal transmission parameters for transmitting messages between the sending network component and the receiving network component based on the calculated transmission delay, wherein estimating of the optimal transmission parameters substant

Abstract: A method for converting video data comprises providing video data in a first format, selecting consecutive pixel data corresponding to a line or fraction of a line of an image, and adapting a maximum length of a data packet to accommodate the selected pixel data. The payload section of a data packet exclusively carries pixel data originating from one single line of the source image. The method further comprises calculating a start address for a memory in a receiver beginning at which address the pixel data is to be written. The start address is added to a header section of the data packet in the transmitter. The data packet is transmitted via a network. In the receiver the pixel data is written to the memory beginning at the start address indicated in the header section. Video data is read from the target memory in accordance with a second format.

Abstract: The invention concerns the technical field of a so-called Path MTU (Maximum Transmission Unit) Discovery process between two computing nodes over packet switched networks. On the path between two hosts (H1, H2, H3) in the network may exist various hops, e.g. routers (R1, R2), a packet needs to pass. Each link between two hops has its own MTU which may differ on each link. Some path MTU discovery algorithms are based on sending probe packets with the DF (don't fragment) bit set in the IP header. However, security devices, e.g. firewalls, often block ICMP messages, including the ICMP error messages that are needed for these path MTU discovery algorithms to work. In order to deal with connections, on which ICMP messages are blocked within the network nodes, the invention relies on acknowledgements of probe packets with MTU sizes of common network technology based MTU values sent back by the destination host.

Abstract: Modern computers (10, 20) come with different timers having different attributes like time resolution, supported time range and time reference. Some are local timers, representing relative time values like the TSC counter (11, 21) counting CPU cycles from the power on or reset of the computer. Some are global timers, representing an absolute or real time. Having different classes of timers in the computer (10, 20), a number of computations need to be performed to tie the different timers to each other. It is the idea of the invention to define a single high resolution timer structure wherein the time value is represented with a digital number and a flag clarifies whether the timer is a global timer or local timer. The invention enables a much faster processing of the time values. The global time, tied to a high-resolution timer can be tracked much faster. This means better precision of scheduling of time critical jobs, like packet scheduling for data transport.

Abstract: A method of managing a packet administration map for data packets to be received via a network. A receiver in the network monitors sequence numbers and stores missing sequence numbers within an internal data structure, called a packet administration map. A reversed keying is used which means that the upper limit of the range of contiguous missing data packets is used as the key entry in the administration map.

Abstract: A method for converting video data comprises providing video data in a first format, selecting consecutive pixel data corresponding to a line or fraction of a line of an image, and adapting a maximum length of a data packet to accommodate the selected pixel data. The payload section of a data packet exclusively carries pixel data originating from one single line of the source image. The method further comprises calculating a start address for a memory in a receiver beginning at which address the pixel data is to be written. The start address is added to a header section of the data packet in the transmitter. The data packet is transmitted via a network. In the receiver the pixel data is written to the memory beginning at the start address indicated in the header section. Video data is read from the target memory in accordance with a second format.

Abstract: A method for sending data over a network from a host computer. The host computer includes an operating system comprising at least a user space and a kernel space. The amount of data provided from the user space to the kernel space within one system call exceeds the size of an IP packet. A loop function in an application in the user space sends multiple packets to the kernel space within a single system call containing IO vectors which contain pointers to the data in the user space. A last data unit being processed may be designated using a flag included in the message header. In the kernel space a second loop function is used to reassemble the vector groups and pass them down the network stack. The data may then be passed to the network hardware using a direct memory access transfer directly from the user space to the network hardware.

Abstract: The invention relates to a method and a device for controlling access to multiple applications which are each implemented as a client application in an operating system environment of a data processing device from a shared memory system. The problem addressed by the invention is that of providing an improved method and an improved device for controlling access to multiple applications which are each implemented as a client application in an operating system environment of a data processing device from a shared memory system, which allow an efficient exchange of data for input/output. In particular, interaction with multimedia data in such an operating environment should be optimized.

Abstract: A method and apparatus for file access in a storage access network (SAN) wherein a portion of a first file is accessed and an access rate computed based on time and amount of data accessed. If the computed access rate is less than an expected rate, a problem is identified and analysis performed. A first analysis accesses the first file through a second link to determine if the link is the problem. If the first file is accessed at an expected rate, the first link is identified as the problem and the file is accessed through an alternate link. A second analysis accesses a second file through the first link. If the second file is accessed at an expected rate, the first file is identified as the problem and the second file is accessed through the first link.