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Zeta-TCP
Zeta-TCP refers to a set of proprietary Transmission Control Protocol (TCP) algorithms aiming at improving the end-to-end performance of TCP, regardless of whether the peer is Zeta-TCP or any other TCP protocol stack, in other words, to be compatible with the existing TCP algorithms. It was designed and implemented by AppEx Networks Corporation. Zeta-TCP offers the following improvements primarily: * TCP congestion avoidance algorithm, Congestion avoidance based on both latency and loss measures. * Improved loss-detection algorithm. * Reverse control. Congestion avoidance Most of the TCP stack implementations today use TCP congestion avoidance algorithm#TCP New Reno, TCP New Reno or its variations (such as TCP SACRFC3517 as the congestion avoidance algorithm. The New Reno-based algorithms are loss-based. Loss-based algorithms treat the packet losses as the sole indication of the congestions in the network. As the Internet has since evolved, this assumption is often an overkill t ... [...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] |
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] |
Fading
In wireless communications, fading is variation of the attenuation of a signal with various variables. These variables include time, geographical position, and radio frequency. Fading is often modeled as a random process. A fading channel is a communication channel that experiences fading. In wireless systems, fading may either be due to multipath propagation, referred to as multipath-induced fading, weather (particularly rain), or shadowing from obstacles affecting the wave propagation, sometimes referred to as shadow fading. Key concepts The presence of reflectors in the environment surrounding a transmitter and receiver create multiple paths that a transmitted signal can traverse. As a result, the receiver sees the superposition of multiple copies of the transmitted signal, each traversing a different path. Each signal copy will experience differences in attenuation, delay and phase shift while traveling from the source to the receiver. This can result in either construc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Round-trip Delay Time
In telecommunications, round-trip delay (RTD) or round-trip time (RTT) is the amount of time it takes for a signal to be sent ''plus'' the amount of time it takes for acknowledgement of that signal having been received. This time delay includes propagation times for the paths between the two communication endpoints. In the context of computer networks, the signal is typically a data packet. RTT is also known as ping time, and can be determined with the ping command. End-to-end delay is the length of time it takes for a signal to travel in one direction and is often approximated as half the RTT. Protocol design Round-trip delay and bandwidth are independent of each other. As the available bandwidth of networks increases, the round trip time does not similarly decrease, as it depends primarily on constant factors such as physical distance and the speed of signal propagation. Networks with both high bandwidth and a high RTT (and thus high bandwidth-delay product) can have very larg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TCP Vegas
TCP Vegas is a TCP congestion avoidance algorithm that emphasizes packet delay, rather than packet loss, as a signal to help determine the rate at which to send packets. It was developed at the University of Arizona by Lawrence Brakmo and Larry L. Peterson and introduced in 1994. TCP Vegas detects congestion at an incipient stage based on increasing Round-Trip Time (RTT) values of the packets in the connection unlike other flavors such as Reno, New Reno, etc., which detect congestion only after it has actually happened via packet loss. The algorithm depends heavily on accurate calculation of the Base RTT value. If it is too small then throughput of the connection will be less than the bandwidth available while if the value is too large then it will overrun the connection. A lot of research is going on regarding the fairness provided by the linear increase/decrease mechanism for congestion control in Vegas. One interesting caveat is when Vegas is inter-operated with other version ... [...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] |
Netfilter
Netfilter is a framework provided by the Linux kernel that allows various networking-related operations to be implemented in the form of customized handlers. Netfilter offers various functions and operations for packet filtering, network address translation, and port translation, which provide the functionality required for directing packets through a network and prohibiting packets from reaching sensitive locations within a network. Netfilter represents a set of hooks inside the Linux kernel, allowing specific kernel modules to register callback functions with the kernel's networking stack. Those functions, usually applied to the traffic in the form of filtering and modification rules, are called for every packet that traverses the respective hook within the networking stack. History Rusty Russell started the ''netfilter/iptables project'' in 1998; he had also authored the project's predecessor, ipchains. As the project grew, he founded the ''Netfilter Core Team'' (or si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Network Driver Interface Specification
The Network Driver Interface Specification (NDIS) is an application programming interface (API) for network interface controllers (NICs). Specification It was jointly developed by Microsoft and 3Com Corporation and is mostly used in Microsoft Windows. However, the open-source NDISwrapper and Project Evil driver wrapper projects allow many NDIS-compliant NICs to be used with Linux, FreeBSD and NetBSD. magnussoft ZETA, a derivative of BeOS, supports a number of NDIS drivers. The NDIS forms the logical link control (LLC) sublayer, which is the upper sublayer of the OSI data link layer (layer 2). Therefore, the NDIS acts as the interface between the media access control (MAC) sublayer, which is the lower sublayer of the data link layer, and the network layer (layer 3). The NDIS is a library of functions often referred to as a " wrapper" that hides the underlying complexity of the NIC hardware and serves as a standard interface for level 3 network protocol drivers and hardware lev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internet Protocols
The Internet protocol suite, commonly known as TCP/IP, is a framework for organizing the set of communication protocols used in the Internet and similar computer networks according to functional criteria. The foundational protocols in the suite are the Transmission Control Protocol (TCP), the User Datagram Protocol (UDP), and the Internet Protocol (IP). In the development of this networking model, early versions of it were known as the Department of Defense (DoD) model because the research and development were funded by the United States Department of Defense through DARPA. The Internet protocol suite provides end-to-end data communication specifying how data should be packetized, addressed, transmitted, routed, and received. This functionality is organized into four abstraction layers, which classify all related protocols according to each protocol's scope of networking. An implementation of the layers for a particular application forms a protocol stack. From lowest to high ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
