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Grease (networking)
Protocol ossification is the loss of flexibility, extensibility and evolvability of network protocols. This is largely due to middleboxes that are sensitive to the wire image (networking), wire image of the protocol, and which can interrupt or interfere with messages that are valid but which the middlebox does not correctly recognise. This is a violation of the end-to-end principle. Secondary causes include inflexibility in endpoint implementations of protocols. Ossification is a major issue in Internet protocol design and deployment, as it can prevent new protocols or extensions from being deployed on the Internet, or place strictures on the design of new protocols; new protocols may have to be encapsulation (networking), encapsulated in an already-deployed protocol or mimic the wire image of another protocol. Because of ossification, the Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) are the only practical choices for transport protocols on the Internet, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extensibility
Extensibility is a software engineering and systems design principle that provides for future growth. Extensibility is a measure of the ability to extend a system and the level of effort required to implement the extension. Extensions can be through the addition of new functionality or through modification of existing functionality. The principle provides for enhancements without impairing existing system functions. An extensible system is one whose internal structure and dataflow are minimally or not affected by new or modified functionality, for example recompiling or changing the original source code might be unnecessary when changing a system’s behavior, either by the creator or other programmers. Because software systems are long lived and will be modified for new features and added functionalities demanded by users, extensibility enables developers to expand or add to the software’s capabilities and facilitates systematic reuse. Some of its approaches include facilit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tragedy Of The Commons
The tragedy of the commons is the concept that, if many people enjoy unfettered access to a finite, valuable resource, such as a pasture, they will tend to overuse it and may end up destroying its value altogether. Even if some users exercised voluntary restraint, the other users would merely replace them, the predictable result being a "tragedy" for all. The concept has been widely discussed, and criticised, in economics, ecology and other sciences. The metaphorical term is the title of a 1968 essay by ecologist Garrett Hardin. The concept itself did not originate with Hardin but rather extends back to classical antiquity, being discussed by Aristotle. The principal concern of Hardin's essay was overpopulation of the planet. To prevent the inevitable tragedy (he argued) it was necessary to reject the principle (supposedly enshrined in the Universal Declaration of Human Rights) according to which every family has a right to choose the number of its offspring, and to replace it b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BSD Sockets API
A Berkeley (BSD) socket is an application programming interface (API) for Internet domain sockets and Unix domain sockets, used for inter-process communication (IPC). It is commonly implemented as a library of linkable modules. It originated with the 4.2BSD Unix operating system, which was released in 1983. A socket is an abstract representation (handle) for the local endpoint of a network communication path. The Berkeley sockets API represents it as a file descriptor in the Unix philosophy that provides a common interface for input and output to streams of data. Berkeley sockets evolved with little modification from a ''de facto'' standard into a component of the POSIX specification. The term POSIX sockets is essentially synonymous with ''Berkeley sockets'', but they are also known as BSD sockets, acknowledging the first implementation in the Berkeley Software Distribution. History and implementations Berkeley sockets originated with the 4.2BSD Unix operating system, released ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stream Control Transmission Protocol
The Stream Control Transmission Protocol (SCTP) is a computer networking communications protocol in the transport layer of the Internet protocol suite. Originally intended for Signaling System 7 (SS7) message transport in telecommunication, the protocol provides the message-oriented feature of the User Datagram Protocol (UDP), while ensuring reliable, in-sequence transport of messages with TCP congestion control, congestion control like the Transmission Control Protocol (TCP). Unlike UDP and TCP, the protocol supports multihoming and redundant paths to increase resilience and reliability. SCTP is standardized by the Internet Engineering Task Force (IETF) in . The SCTP reference implementation was released as part of FreeBSD version 7, and has since been widely ported to other platforms. Formal oversight The IETF Signaling Transport (SIGTRAN) working group defined the protocol (number 132) in October 2000, and the IETF Transport Area (TSVWG) working group maintains it. defines t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TCP Fast Open
In computer networking, TCP Fast Open (TFO) is an extension to speed up the opening of successive Transmission Control Protocol (TCP) connections between two endpoints. It works by using a ''TFO cookie'' (a TCP option), which is a cryptographic cookie stored on the client and set upon the initial connection with the server. When the client later reconnects, it sends the initial SYN packet along with the TFO cookie data to authenticate itself. If successful, the server may start sending data to the client even before the reception of the final ACK packet of the three-way handshake, thus skipping a round-trip delay and lowering the latency in the start of data transmission. The cookie is generated by applying a block cipher keyed on a key held secret by the server to the client's, generating an authentication tag that is difficult for third parties to spoof, even if they can forge a source IP address or make two-way connections to the same server from other IP addresses. Although it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MPTCP
Multipath TCP (MPTCP) is an ongoing effort of the Internet Engineering Task Force's (IETF) Multipath TCP working group, that aims at allowing a Transmission Control Protocol (TCP) connection to use multiple paths to maximize Network throughput, throughput and increase redundancy. In January 2013, the IETF published the Multipath specification as an Experimental standard in . It was replaced in March 2020 by the Multipath TCP v1 specification in . Benefits The redundancy offered by Multipath TCP enables inverse multiplexing of resources, and thus increases TCP throughput to the sum of all available link layer, link-level channels instead of using a single one as required by standard TCP. Multipath TCP is backward compatible with standard TCP. Multipath TCP is particularly useful in the context of wireless networks; using both Wi-Fi and a mobile network is a typical use case. In addition to the gains in throughput from inverse multiplexing, links may be added or dropped as the use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EDNS
Extension Mechanisms for DNS (EDNS) is a specification for expanding the size of several parameters of the Domain Name System (DNS) protocol which had size restrictions that the Internet engineering community deemed too limited for increasing functionality of the protocol. The first set of extensions was published in 1999 by the Internet Engineering Task Force as , also known as EDNS0 which was updated by in 2013 changing abbreviation slightly to EDNS(0). Motivation The Domain Name System was first developed in the early 1980s. Since then, it has been progressively enhanced with new features, while maintaining compatibility with earlier versions of the protocol. The restrictions in the size of several flags fields, return codes and label types available in the basic DNS protocol prevented the support of some desirable features. Moreover, DNS messages carried by UDP were restricted to 512 bytes, not considering the Internet Protocol (IP) and transport layer headers. Resorting t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flag Day (computing)
A flag day, as used in system administration, is a change which requires a complete restart or conversion of a sizable body of software or data. The change is large and expensive, and—in the event of failure—similarly difficult and expensive to reverse. The situation may arise if there are limitations on backward compatibility and forward compatibility among system components, which then requires that updates be performed almost simultaneously (during a "flag day cutover") for the system to function after the upgrade. This contrasts with the method of gradually phased-in upgrades, which avoids the disruption of service caused by ''en masse'' upgrades. This systems terminology originates from a major change in the Multics operating system's definition of ASCII, which was scheduled for the United States holiday, Flag Day, on June 14, 1966. Another historical flag day was January 1, 1983, when the ARPANET changed from NCP to the TCP/IP protocol suite. This major change required ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
User-space
A modern computer operating system usually uses virtual memory to provide separate address spaces or regions of a single address space, called user space and kernel space. This separation primarily provides memory protection and hardware protection from malicious or errant software behaviour. Kernel space is strictly reserved for running a privileged operating system kernel, kernel extensions, and most device drivers. In contrast, user space is the memory area where application software and some drivers execute, typically with one address space per process. Overview The term user space (or userland) refers to all code that runs outside the operating system's kernel. User space usually refers to the various programs and libraries that the operating system uses to interact with the kernel: software that performs input/output, manipulates file system objects, application software, etc. Each user space process usually runs in its own virtual memory space, and, unless explicitl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HTTP Headers
HTTP header fields are a list of strings sent and received by both the client program and server on every HTTP request and response. These headers are usually invisible to the end-user and are only processed or logged by the server and client applications. They define how information sent/received through the connection are encoded (as in Content-Encoding), the session verification and identification of the client (as in browser cookies, IP address, user-agent) or their anonymity thereof (VPN or proxy masking, user-agent spoofing), how the server should handle data (as in Do-Not-Track or Global Privacy Control), the age (the time it has resided in a shared cache) of the document being downloaded, amongst others. General format In HTTP version 1.x, header fields are transmitted after the request line (in case of a request HTTP message) or the response line (in case of a response HTTP message), which is the first line of a message. Header fields are colon-separated key-valu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chaos Engineering
Chaos engineering is the discipline of experimenting on a system in order to build confidence in the system's capability to withstand turbulent conditions in production. Concept In software development, the ability of a given software to tolerate failures while still ensuring adequate quality of service—often termed ''resilience''—is typically specified as a requirement. However, development teams may fail to meet this requirement due to factors such as short deadlines or lack of domain knowledge. Chaos engineering encompasses techniques aimed at meeting resilience requirements. Chaos engineering can be used to achieve resilience against infrastructure failures, network failures, and application failures. Operational readiness using chaos engineering Calculating how much confidence we have in the interconnected complex systems that are put into production environments requires operational readiness metrics. Operational readiness can be evaluated using chaos engineering s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Message Authentication
In information security, message authentication or data origin authentication is a property that a message has not been modified while in transit (data integrity) and that the receiving party can verify the source of the message. Description Message authentication or data origin authentication is an information security property that indicates that a message has not been modified while in transit (data integrity) and that the receiving party can verify the source of the message. Message authentication does not necessarily include the property of non-repudiation. Techniques Message authentication is typically achieved by using message authentication codes (MACs), authenticated encryption (AE), or digital signatures. The message authentication code, also known as digital authenticator, is used as an integrity check based on a secret key shared by two parties to authenticate information transmitted between them. It is based on using a cryptographic hash or symmetric encryptio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
