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H-TCP
H-TCP is another implementation of TCP with an optimized congestion control algorithm for high speed networks with high latency (LFN: Long Fat Networks). It was created by researchers at the Hamilton Institute in Ireland. H-TCP is an optional module in Linux since kernel version 2.6, and has been implemented for FreeBSD 7. Principles of operation H-TCP is a loss-based algorithm, using additive-increase/multiplicative-decrease (AIMD) to control TCP's congestion window. It is one of many TCP congestion avoidance algorithms which seeks to increase the aggressiveness of TCP on high bandwidth-delay product (BDP) paths, while maintaining "TCP friendliness" for small BDP paths. H-TCP increases its aggressiveness (in particular, the rate of additive increase) as the time since the previous loss increases. This avoids the problem encountered by HSTCP and BIC TCP of making flows more aggressive if their windows are already large. Thus, new flows can be expected to converge to fai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TCP Reno
Transmission Control Protocol (TCP) uses a network congestion-avoidance algorithm that includes various aspects of an additive increase/multiplicative decrease (AIMD) scheme, along with other schemes including slow start and congestion window (CWND), to achieve congestion avoidance. The TCP congestion-avoidance algorithm is the primary basis for congestion control in the Internet. Per the end-to-end principle, congestion control is largely a function of internet hosts, not the network itself. There are several variations and versions of the algorithm implemented in protocol stacks of operating systems of computers that connect to the Internet. To avoid congestive collapse, TCP uses multi-faceted congestion-control strategy. For each connection, TCP maintains a CWND, limiting the total number of unacknowledged packets that may be in transit end-to-end. This is somewhat analogous to TCP's sliding window used for flow control. Additive increase/multiplicative decrease The addi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TCP Congestion Avoidance Algorithms
Transmission Control Protocol (TCP) uses a network congestion-avoidance algorithm that includes various aspects of an additive increase/multiplicative decrease (AIMD) scheme, along with other schemes including slow start and congestion window (CWND), to achieve congestion avoidance. The TCP congestion-avoidance algorithm is the primary basis for congestion control in the Internet. Per the end-to-end principle, congestion control is largely a function of internet hosts, not the network itself. There are several variations and versions of the algorithm implemented in protocol stacks of operating systems of computers that connect to the Internet. To avoid congestive collapse, TCP uses multi-faceted congestion-control strategy. For each connection, TCP maintains a CWND, limiting the total number of unacknowledged packets that may be in transit end-to-end. This is somewhat analogous to TCP's sliding window used for flow control. Additive increase/multiplicative decrease The addi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TCP Congestion Avoidance Algorithm
Transmission Control Protocol (TCP) uses a network congestion-avoidance algorithm that includes various aspects of an additive increase/multiplicative decrease (AIMD) scheme, along with other schemes including slow start and congestion window (CWND), to achieve congestion avoidance. The TCP congestion-avoidance algorithm is the primary basis for congestion control in the Internet. Per the end-to-end principle, congestion control is largely a function of internet hosts, not the network itself. There are several variations and versions of the algorithm implemented in protocol stacks of operating systems of computers that connect to the Internet. To avoid congestive collapse, TCP uses multi-faceted congestion-control strategy. For each connection, TCP maintains a CWND, limiting the total number of unacknowledged packets that may be in transit end-to-end. This is somewhat analogous to TCP's sliding window used for flow control. Additive increase/multiplicative decrease The ad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HTCP
Hypertext Caching Protocol (abbreviated to HTCP) is used for discovering HTTP caches and cached data, managing sets of HTTP caches and monitoring cache activity. It permits full request and response headers to be used in cache management and expands the domain of cache management to include monitoring a remote cache's additions and deletions, requesting immediate deletions and sending hints about web objects such as the third party locations of cacheable objects or unavailability of web objects. Features All multi-octet HTCP protocol elements are transmitted in network byte order. All reserved fields should be set to binary zero by senders and left unexamined by receivers. Headers must be presented with the CRLF line termination, as in HTTP. Any hostnames specified should be compatible between sender and receiver, such that if a private naming scheme (such as HOSTS.TXT or NIS) is in use, names depending on such schemes will only be sent to HTCP neighbors who are known to parti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hamilton Institute
The Hamilton Institute is a multi-disciplinary research centre at Maynooth University, named after William Rowan Hamilton, arguably Ireland's most distinguished mathematician. The Hamilton Institute was formally established in November 2001 under the first round of funding, by Science Foundation Ireland (SFI). It was officially opened by Bill Harris, SFI Director-General with the inaugural lecture being given by Kevin Warwick. Since 2001 the institute grew to a size to around 45 full-time researchers in 2008. From 2001 until 2014 the institute Director was Prof. Douglas Leith. From 2015 to 2017 Prof. Fiona Lyddy was director and in 2017, Prof. Ken Duffy became the Institute's director. Since its founding, the institute has been successful in winning a number of large research grants, in addition to the original seed funding grant from SFI, including the €4.7M National Communications Network Research Centre, a €2.5M Systems Biology initiative, the €2.7M Next Generation Int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FAST TCP
FAST TCP (also written FastTCP) is a TCP congestion avoidance algorithm especially targeted at long-distance, high latency links, developed at the Netlab, California Institute of Technology and now being commercialized by FastSoft. FastSoft was acquired by Akamai Technologies in 2012. FastTCP is compatible with existing TCP algorithms, requiring modification only to the computer which is sending data. Name The name FAST is a recursive acronym for FAST AQM Scalable TCP, where AQM stands for Active Queue Management, and TCP stands for Transmission Control Protocol. Principles of operation The role of congestion control is to moderate the rate at which data is transmitted, "congestion", according to the capacity of the network and the rate at which other users are transmitting. Like TCP Vegas, FAST TCP uses queueing delay instead of loss probability as a congestion signal. Most current congestion control algorithms detect congestion and slow down when they discover that packe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmission Control Protocol
The Transmission Control Protocol (TCP) is one of the main protocols of the Internet protocol suite. It originated in the initial network implementation in which it complemented the Internet Protocol (IP). Therefore, the entire suite is commonly referred to as TCP/IP. TCP provides reliable, ordered, and error-checked delivery of a stream of octets (bytes) between applications running on hosts communicating via an IP network. Major internet applications such as the World Wide Web, email, remote administration, and file transfer rely on TCP, which is part of the Transport Layer of the TCP/IP suite. SSL/TLS often runs on top of TCP. TCP is connection-oriented, and a connection between client and server is established before data can be sent. The server must be listening (passive open) for connection requests from clients before a connection is established. Three-way handshake (active open), retransmission, and error detection adds to reliability but lengthens latency. Applica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Congestion Control Algorithm
Network congestion in data networking and queueing theory is the reduced quality of service that occurs when a network node or link is carrying more data than it can handle. Typical effects include queueing delay, packet loss or the blocking of new connections. A consequence of congestion is that an incremental increase in offered load leads either only to a small increase or even a decrease in network throughput. Network protocols that use aggressive retransmissions to compensate for packet loss due to congestion can increase congestion, even after the initial load has been reduced to a level that would not normally have induced network congestion. Such networks exhibit two stable states under the same level of load. The stable state with low throughput is known as congestive collapse. Networks use congestion control and congestion avoidance techniques to try to avoid collapse. These include: exponential backoff in protocols such as CSMA/CA in 802.11 and the similar CSMA/CD i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linux
Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which includes the kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name "GNU/Linux" to emphasize the importance of GNU software, causing some controversy. Popular Linux distributions include Debian, Fedora Linux, and Ubuntu, the latter of which itself consists of many different distributions and modifications, including Lubuntu and Xubuntu. Commercial distributions include Red Hat Enterprise Linux and SUSE Linux Enterprise. Desktop Linux distributions include a windowing system such as X11 or Wayland, and a desktop environment such as GNOME or KDE Plasma. Distributions intended for ser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kernel (computer Science)
The kernel is a computer program at the core of a computer's operating system and generally has complete control over everything in the system. It is the portion of the operating system code that is always resident in memory and facilitates interactions between hardware and software components. A full kernel controls all hardware resources (e.g. I/O, memory, cryptography) via device drivers, arbitrates conflicts between processes concerning such resources, and optimizes the utilization of common resources e.g. CPU & cache usage, file systems, and network sockets. On most systems, the kernel is one of the first programs loaded on startup (after the bootloader). It handles the rest of startup as well as memory, peripherals, and input/output (I/O) requests from software, translating them into data-processing instructions for the central processing unit. The critical code of the kernel is usually loaded into a separate area of memory, which is protected from access by applicati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Packet Loss
Packet loss occurs when one or more packets of data travelling across a computer network fail to reach their destination. Packet loss is either caused by errors in data transmission, typically across wireless networks, or network congestion.Kurose, J.F. & Ross, K.W. (2010). ''Computer Networking: A Top-Down Approach''. New York: Addison-Wesley. Packet loss is measured as a percentage of packets lost with respect to packets sent. The Transmission Control Protocol (TCP) detects packet loss and performs retransmissions to ensure reliable messaging. Packet loss in a TCP connection is also used to avoid congestion and thus produces an intentionally reduced throughput for the connection. In real-time applications like streaming media or online games, packet loss can affect a user's quality of experience (QoE). Causes The Internet Protocol (IP) is designed according to the end-to-end principle as a best-effort delivery service, with the intention of keeping the logic routers mus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HSTCP
HighSpeed TCP (HSTCP) is a congestion control algorithm protocol defined in RFC 3649 for Transport Control Protocol (TCP). Standard TCP performs poorly in networks with a large bandwidth-delay product. It is unable to fully utilize available bandwidth. HSTCP makes minor modifications to standard TCP's congestion control mechanism to overcome this limitation. Algorithm When an ACK is received (in congestion avoidance), the window is increased by a(w)/w and when a loss is detected through triple duplicate acknowledgments, the window equals (1-b(w))w, where w is the current window size. When the congestion window is small, HSTCP behaves exactly like standard TCP so a(w) is 1 and b(w) is 0.5. When TCP's congestion window is beyond a certain threshold, a(w) and b(w) become functions of the current window size. In this region, as the congestion window increases, the value of a(w) increases and the value of b(w) decreases. This means that HSTCP's window will grow faster than standard ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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