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System in package

A system in package (SiP) or system-in-a-package is a number of integrated circuits enclosed in a single module (package). The SiP performs all or most of the functions of an electronic system, and is typically used inside a mobile phone, digital music player, etc. Dies containing integrated circuits may be stacked vertically on a substrate. They are internally connected by fine wires that are bonded to the package. Alternatively, with a flip chip technology, solder bumps are used to join stacked chips together.

SiP dies can be stacked vertically or tiled horizontally, unlike slightly less dense multi-chip modules, which place dies horizontally on a carrier. SiP connects the dies with standard off-chip wire bonds or solders bumps, unlike slightly denser three-dimensional integrated circuits which connect stacked silicon dies with conductors running through the die.

Many different 3-D packaging techniques have been developed for stacking many more-or-less standard chip dies into a compact area.

An example SiP can contain several chips –such as a specialized processor, DRAM, flash memory – combined with passive components– resistors and  capacitors – all mounted on the same substrate. This means that a complete functional unit can be built in a multi-chip package, so that few external components need to be added to make it work.

Systemon a chip

A system on a chip or system on chip (SoC or SOC) is an integrated circuit (IC) that integrates all components of a computer or other electronic system into a single chip. It may contain digital, analog, mixed-signal, and often radio-frequency functions – all on a single chip substrate. SoCs are very common in the mobile electronics market because of their low power consumption. A typical application is in the area of embedded systems.

Locator/Identifier Separation Protocol

Locator/ID Separation Protocol (LISP) is a “map-and-encapsulate” protocol which is developed by the Internet Engineering Task Force LISP WorkingGroup. The basic idea behind the separation is that the Internet architecture combines two functions, routing locators (where a client is attached to the network) and identifiers (who the client is) in one number space: the IP address. LISP supports the separation of the IPv4 and IPv6 address space following a network-based map-and-encapsulate scheme. In LISP, both identifiers and locators can be IP addresses or  arbitrary elements like a set of GPS coordinates or MAC address.

Dictionary attack

In cryptanalysis and computer security, adictionary attack is a technique for defeating a cipher or authentication mechanism by trying to determine its decryption key or pass phrase by trying hundreds or sometimes millions of likely possibilities, such as words in a dictionary.

Pre-computed dictionary attack/ Rainbow table attack

It is possible to achieve a time-space trade off by pre-computing a list of hashes of dictionary words, and storing these in a database using the hash as the key. This requires a considerable amount of preparation time, but allows the actual attack to be executed faster.

Denial-of-service attack

In computing, a denial-of-service (DoS)attack is an attempt to make a machine or network resource unavailable to itsintended users, such as to temporarily or indefinitely interrupt or suspendservices of a host connected to the Internet. Denial of service is typicallyaccomplished by flooding the targeted machine or resource with superfluousrequests in an attempt to overload systems and prevent some or all legitimaterequests from being fulfilled.

A distributed denial-of-service (DDos) iswhere the attack source is more than one, often thousands of, unique IPaddresses. It is analogous to a group of people crowding the entry door or gateto a shop or business, and not letting legitimate parties enter into the shopor business, disrupting normal operations. The scale of DDoS attacks hascontinued to rise over recent years, even reaching over 400Gbit/s.

Criminal perpetrators of DoS and DDoSattacks often target sites or services hosted on high-profile web servers suchas banks, credit card payment gateways.

Attacktechniques

A denial-of-service attack is characterizedby an explicit attempt by attackers to prevent legitimate users of a servicefrom using that service. There are two general forms of DoS attacks: those thatcrash services and those that flood services.

The most serious attacks are distributedand in many or most cases involve forging of IP sender addresses so that thelocation of the attacking machines cannot easily be identified, nor canfiltering be done based on the source address.

Defensetechniques

Defensive responses of denial-of-service attackstypically involve the use of a combination of attack detection, trafficclassification and response tools, aiming to block traffic that they identifyas illegitimate and allow traffic that they identify as legitimate.

Single-board computer

A single-board computer (SBC) is a completecomputer built on a single circuit board, with microprocessor, memory,input/output and other features required of a functional computer.

Single-board computers were made asdemonstration or development systems, for educational systems, or for use asembedded computer controllers. Many types of home computer or portable computerintegrated all their functions onto a single printed circuit board.

Unlike a desktop personal computer, singleboard computers often do not rely on expansion slots for peripheral functionsor expansion. Some single-board computers are made to plug into a backplane forsystem expansion. Single board computers have been built using a wide range ofmicroprocessors. Simple designs, such as built by computer hobbyists, often usestatic RAM and low-cost 8 or 16 bit processors.

Software-definednetworking

Software-defined networking (SDN) is anapproach to computer networking that allows network administrators is managenetwork services through abstraction of lower-level functionality. SDN is meantto address the fact that the static architecture of traditional networks doesn’tsupport the dynamic, scalable computing and storage needs of more moderncomputing environments such as data centers. This is done by decoupling ordisassociating the system that makes decisions about where traffic is sent fromthe underlying systems that forward traffic to the selected destination.

Concept

Software-defined networking (SDN) is an architecturepurporting to be dynamic, manageable, cost-effective, and adaptable, seeking tobe suitable for the high-bandwidth, dynamic nature of today’s applications. SDNarchitectures decouple network control and forwarding functions, enablingnetwork control to become directly programmable and the underlying infrastructureto be abstracted from applications and network services.

Content delivery network

A content delivery network or contentdistribution network (CDN) is a globally distributed network of proxy servers deployedin multiple data centers. The goal of a CDN is to serve content to end-userswith high availability and high performance. CDNs serve a large fraction of theInternet content today, including web objects (text, graphics and scripts),downloadable objects (media files, software, documents), applications(e-commerce, portals), live streaming media, on-demand streaming media, andsocial networks.

Content providers such as media companiesand e-commerce vendors pay CDN operators to deliver their content to theiraudience of end-users. In turn, a CDN pays ISPs, carriers, and networkoperators for hosting its servers in their data centers. Besides betterperformance and availability, CDNs also offload the traffic served directlyfrom the content provider’s origin infrastructure, resulting in possible costsavings for the content provider. In addition, CDNs provide the contentprovider a degree of protection from DoS attack by using their largedistributed server infrastructure to absorb the attack traffic.

Voice over IP

Voice over Internet Protocol (Voice overIP, VoIP and IP telephony) is a methodology and group of technologies for thedelivery of voice communications and multimedia sessions over Internet Protocol(IP) networks, such as the Internet. The terms Internet telephony, broadbandtelephony, and broadband phone service specifically refer to the provisioningof communications services (voice, fax, SMS, voice-messaging) over the publicInternet, rather than via the public switched telephone network (PSTN).

The steps ad principles involved inoriginating VoIP telephone calls are similar to traditional digital telephonyand involve signaling, channel setup, digitization of the analog voice signals,and encoding. Instead of being transmitted over a circuit-switch network,however, the digital information is packetized, and transmission occurs as IPpackets over a packet-switched network.

Early providers of voice-over-IP servicesoffered business models and technical solutions that mirrored the architectureof the legacy telephone network. Second-generation providers, such as Skype,have built closed networks for private user bases, offering the benefit of freecalls and convenience while poetically charging for access to othercommunication networks, such as the PSTN. This has limited the freedom of usersto mix-and-match third-party hardware and software. Third-generation providers,such as Google Talk, have adopted the concept of federated VoIP – which is adeparture from the architecture of the legacy networks. These solutionstypically allow dynamic interconnection between users on any two domains on theInternet when a user wishes to place a call.

Push-to-talk

Push-to-talk (PTT), also known aspress-to-transmit, is a method of having conversations or talking onhalf-duplex communication lines, including two-way radio, using a momentarybutton to switch from voice reception mode to transmit mode.