text stringlengths 0 73.6k | source stringclasses 4
values |
|---|---|
Ethanol fermentation-Byproducts of fermentation-Ethanol fermentation produces unharvested byproducts such as heat, carbon dioxide, food for livestock, water, methanol, fuels, fertilizer and alcohols. The cereal unfermented solid residues from the fermentation process, which can be used as livestock feed or in the produ... | milkshake721/2.1M-wiki-STEM |
Ethanol fermentation-Microbes used in ethanol fermentation-Yeast Saccharomyces cerevisiae Schizosaccharomyces Zymomonas mobilis (a bacterium) | milkshake721/2.1M-wiki-STEM |
Peroxide process-Peroxide process-The peroxide process is a method for the industrial production of hydrazine. | milkshake721/2.1M-wiki-STEM |
Peroxide process-Peroxide process-In this process hydrogen peroxide is used as an oxidant instead of sodium hypochlorite, which is traditionally used to generate hydrazine. The main advantage of the peroxide process to hydrazine relative to the traditional Olin Raschig process is that it does not coproduce salt. In thi... | milkshake721/2.1M-wiki-STEM |
Peroxide process-Production-Ketazine formation In the usual implementation, hydrogen peroxide is used together with acetamide. This mixture does not react with ammonia directly but does so in the presence of methyl ethyl ketone to give the oxaziridine. | milkshake721/2.1M-wiki-STEM |
Peroxide process-Production-Balanced equations for the individual steps are as follows. Imine formation through condensation: Me(Et)C=O + NH3 → Me(Et)C=NH + H2OOxidation of the imine to the oxaziridine: Me(Et)C=NH + H2O2 → Me(Et)CONH + H2OCondensation of the oxaziridine with a second molecule of ammonia to give the hyd... | milkshake721/2.1M-wiki-STEM |
Peroxide process-Production-Ketazine to hydrazine The final stage involves hydrolysis of the purified ketazine: Me(Et)C=NN=C(Et)Me + 2 H2O → 2 Me(Et)C=O + N2H4The hydrolysis of the azine is acid-catalyzed, hence the need to isolate the azine from the initial ammonia-containing reaction mixture. It is also endothermic, ... | milkshake721/2.1M-wiki-STEM |
Peroxide process-History-The peroxide process, also called the Pechiney–Ugine–Kuhlmann process, was developed in the early 1970s by Produits Chimiques Ugine Kuhlmann. Originally the process used acetone instead of methyl ethyl ketone. Methyl ethyl ketone is advantageous because the resulting ketazine is immiscible in t... | milkshake721/2.1M-wiki-STEM |
Peroxide process-History-Bayer ketazine process Before invention of the peroxide process, the Bayer ketazine process had been commercialized. In the Bayer process, the oxidation of ammonia by sodium hypochlorite is conducted in the presence of acetone. The process generates the ketazine but also sodium chloride: 2 Me2C... | milkshake721/2.1M-wiki-STEM |
SKF-91488-SKF-91488-SKF-91488 is a histamine N-methyltransferase inhibitor. It prevents the degradation of histamine, leading to increased histamine levels. | milkshake721/2.1M-wiki-STEM |
IAmaze-IAmaze-iAmaze is an Internet company that specializes in web applications created in dynamic HTML. Applications created by the company are designed to run on all browsers and operating systems, without downloads or plug-ins.
AOL purchased the company on September 5, 2000, and commented that "iAmaze will help fur... | milkshake721/2.1M-wiki-STEM |
Time/memory/data tradeoff attack-Time/memory/data tradeoff attack-A time/memory/data tradeoff attack is a type of cryptographic attack where an attacker tries to achieve a situation similar to the space–time tradeoff but with the additional parameter of data, representing the amount of data available to the attacker. A... | milkshake721/2.1M-wiki-STEM |
Time/memory/data tradeoff attack-History-Tradeoff attacks on symmetric cryptosystems date back to 1980, when Martin Hellman suggested a time/memory tradeoff method to break block ciphers with N possible keys in time T and memory M related by the tradeoff curve TM2=N2 where 1≤T≤N . Later, in 1995, Babbage and Golic... | milkshake721/2.1M-wiki-STEM |
Time/memory/data tradeoff attack-Attack mechanics-This attack is a special version of the general cryptanalytic time/memory tradeoff attack, which has two main phases: Preprocessing: During this phase, the attacker explores the structure of the cryptosystem and is allowed to record their findings in large tables. This... | milkshake721/2.1M-wiki-STEM |
Time/memory/data tradeoff attack-Attack mechanics-Realtime: In this phase, the cryptanalyst is granted real data obtained from a specific unknown key. They then try to use this data with the precomputed table from the preprocessing phase to find the particular key in as little time as possible.Any time/memory/data trad... | milkshake721/2.1M-wiki-STEM |
Time/memory/data tradeoff attack-Hellman's attack on block ciphers-For block ciphers, let N be the total number of possible keys and also assume the number of possible plaintexts and ciphertexts to be N . Also let the given data be a single ciphertext block of a specific plaintext counterpart. If we consider the mapp... | milkshake721/2.1M-wiki-STEM |
Time/memory/data tradeoff attack-Babbage-and-Golic attack on stream ciphers-For stream ciphers, N is specified by the number of internal states of the bit generator—probably different from the number of keys. D is the count of the first pseudorandom bits produced from the generator. Finally, the attacker's goal is to... | milkshake721/2.1M-wiki-STEM |
Time/memory/data tradeoff attack-Babbage-and-Golic attack on stream ciphers-Store the pairs (xi,yi) in increasing order of yi in a large table.
During the realtime phase, you have D+log(N)−1 generated bits. Calculate from them all D possible combinations of y1,y2,...,yD, of consecutive bits with length log(N) Sea... | milkshake721/2.1M-wiki-STEM |
Time/memory/data tradeoff attack-Babbage-and-Golic attack on stream ciphers-By the Birthday Paradox, you are guaranteed that two subsets of a space with N points have an intersection if the product of their sizes is greater than N .This result from the Birthday attack gives the condition DM=N with attack time T=D a... | milkshake721/2.1M-wiki-STEM |
Time/memory/data tradeoff attack-Shamir and Biryukov's attack on stream ciphers-This novel idea introduced in 2000 combines the Hellman and Babbage-and-Golic tradeoff attacks to achieve a new tradeoff curve with better bounds for stream cipher cryptoanalysis. Hellman's block cipher technique can be applied to a stream ... | milkshake721/2.1M-wiki-STEM |
Time/memory/data tradeoff attack-Shamir and Biryukov's attack on stream ciphers-Eventually, we again use the matrix stopping rule to obtain the tradeoff curve TM2D2=t2⋅(m2t2/D2)⋅D2=m2t4=N2 for D2≤T≤N (because t≥D ).
Attacks on stream ciphers with low sampling resistance This attack, invented by Biryukov, Shamir, and... | milkshake721/2.1M-wiki-STEM |
Time/memory/data tradeoff attack-Shamir and Biryukov's attack on stream ciphers-Let the stream cipher be of N=2n states each has a full name of n bits and a corresponding output name which is the first n bits in the output sequence of bits. If this stream cipher has sampling resistance R=2−k , then an efficient enu... | milkshake721/2.1M-wiki-STEM |
System console-System console-One meaning of system console, computer console, root console, operator's console, or simply console is the text entry and display device for system administration messages, particularly those from the BIOS or boot loader, the kernel, from the init system and from the system logger. It is ... | milkshake721/2.1M-wiki-STEM |
System console-History-Prior to the development of alphanumeric CRT system consoles, some computers such as the IBM 1620 had console typewriters and front panels while the very first programmable computer, the Manchester Baby, used a combination of electromechanical switches and a CRT to provide console functions—the C... | milkshake721/2.1M-wiki-STEM |
System console-History-Some early operating systems supported either a single keyboard/print or keyboard/display device for controlling the OS. Some also supported a single alternate console, and some supported a hardcopy console for retaining a record of commands, responses and other console messages. However, in the ... | milkshake721/2.1M-wiki-STEM |
System console-History-On early minicomputers, the console was a serial console, an RS-232 serial link to a terminal such as a ASR-33 or later a DECWriter or DEC VT100. This terminal was usually kept in a secured room since it could be used for certain privileged functions such as halting the system or selecting which ... | milkshake721/2.1M-wiki-STEM |
System console-History-On PCs and workstations, the computer's attached keyboard and monitor have the equivalent function. Since the monitor cable carries video signals, it cannot be extended very far. Often, installations with many servers therefore use keyboard/video multiplexers (KVM switches) and possibly video amp... | milkshake721/2.1M-wiki-STEM |
System console-History-Some PC BIOSes, especially in servers, also support serial consoles, giving access to the BIOS through a serial port so that the simpler and cheaper serial console infrastructure can be used. Even where BIOS support is lacking, some operating systems, e.g. FreeBSD and Linux, can be configured for... | milkshake721/2.1M-wiki-STEM |
Biotechnology Heritage Award-Biotechnology Heritage Award-The Biotechnology Heritage Award recognizes individuals who have made significant contributions to the development of biotechnology through discovery, innovation, and public understanding. It is presented annually at the Biotechnology Innovation Organization (BI... | milkshake721/2.1M-wiki-STEM |
Biotechnology Heritage Award-Recipients-The award is given yearly and was first presented in 1999. | milkshake721/2.1M-wiki-STEM |
Biotechnology Heritage Award-Recipients-Ivor Royston, 2020 Janet Woodcock, 2019 William Rastetter, 2018 John C. Martin, 2017 Stanley Norman Cohen, 2016 Moshe Alafi and William K. Bowes, 2015 Robert S. Langer, 2014 George Rosenkranz, 2013 Nancy Chang, 2012 Joshua S. Boger, 2011 Arthur D. Levinson, 2010 Robert T. Fraley,... | milkshake721/2.1M-wiki-STEM |
Varimax rotation-Varimax rotation-In statistics, a varimax rotation is used to simplify the expression of a particular sub-space in terms of just a few major items each. The actual coordinate system is unchanged, it is the orthogonal basis that is being rotated to align with those coordinates. The sub-space found with ... | milkshake721/2.1M-wiki-STEM |
Varimax rotation-Varimax rotation-One way of expressing the varimax criterion formally is this: arg max R(1p∑j=1k∑i=1p(ΛR)ij4−∑j=1k(1p∑i=1p(ΛR)ij2)2).
Suggested by Henry Felix Kaiser in 1958, it is a popular scheme for orthogonal rotation (where all factors remain uncorrelated with one another). | milkshake721/2.1M-wiki-STEM |
Varimax rotation-Rotation in factor analysis-A summary of the use of varimax rotation and of other types of factor rotation is presented in this article on factor analysis. | milkshake721/2.1M-wiki-STEM |
Varimax rotation-Implementations-In the R programming language the varimax method is implemented in several packages including stats (function varimax( )), or in contributed packages including GPArotation or psych.
In SAS varimax rotation is available in PROC FACTOR using ROTATE = VARIMAX. | milkshake721/2.1M-wiki-STEM |
Rack card-Rack card-A rack card is a document used for commercial advertising, frequently in convenience stores, hotels, landmarks, restaurants, rest areas and other locations that enjoy significant foot traffic. Rack cards are typically 4 by 9 inches in size and sport high-impact graphic design. | milkshake721/2.1M-wiki-STEM |
Door-to-balloon-Door-to-balloon-Door-to-balloon is a time measurement in emergency cardiac care (ECC), specifically in the treatment of ST segment elevation myocardial infarction (or STEMI). The interval starts with the patient's arrival in the emergency department, and ends when a catheter guidewire crosses the culpri... | milkshake721/2.1M-wiki-STEM |
Door-to-balloon-Improving door-to-balloon times-Door to Balloon (D2B) Initiative The benefit of prompt, expertly performed primary percutaneous coronary intervention over thrombolytic therapy for acute ST elevation myocardial infarction is now well established. Few hospitals can provide PCI within the 90 minute interva... | milkshake721/2.1M-wiki-STEM |
Door-to-balloon-Improving door-to-balloon times-EMS-to-balloon (E2B) Although incorporating a prehospital 12 lead ECG into critical pathways for STEMI patients is listed as an optional strategy by the D2B Alliance, the fastest median door-to-balloon times have been achieved by hospitals with paramedics who perform 12 l... | milkshake721/2.1M-wiki-STEM |
Door-to-balloon-Common themes in hospitals achieving rapid door-to-balloon times-Bradley et al. (Circulation 2006) performed a qualitative analysis of 11 hospitals in the National Registry of Myocardial Infarction that had median door-to-balloon times = or < 90 minutes. They identified 8 themes that were present in all... | milkshake721/2.1M-wiki-STEM |
Door-to-balloon-Criteria for an ideal primary PCI center-Granger et al. (Circulation 2007) identified the following criteria of an ideal primary PCI center. | milkshake721/2.1M-wiki-STEM |
Door-to-balloon-Criteria for an ideal primary PCI center-Institutional resources Primary PCI is the routine treatment for eligible STEMI patients 24 hours a day, 7 days a week Primary PCI is performed as soon as possible Institution is capable of providing supportive care to STEMI patients and handling complications Wr... | milkshake721/2.1M-wiki-STEM |
Door-to-balloon-Gaps and barriers to timely access to primary PCI-Granger et al. (Circulation 2007) identified the following barriers to timely access to primary PCI. | milkshake721/2.1M-wiki-STEM |
Door-to-balloon-Gaps and barriers to timely access to primary PCI-Busy PCI hospitals may have to divert patients Significant delays in ED diagnosis of STEMI may occur, particularly when patient does not arrive by EMS Manpower and financial considerations may prevent smaller PCI programs from providing primary PCI for S... | milkshake721/2.1M-wiki-STEM |
Damerau–Levenshtein distance-Damerau–Levenshtein distance-In information theory and computer science, the Damerau–Levenshtein distance (named after Frederick J. Damerau and Vladimir I. Levenshtein) is a string metric for measuring the edit distance between two sequences. Informally, the Damerau–Levenshtein distance bet... | milkshake721/2.1M-wiki-STEM |
Damerau–Levenshtein distance-Damerau–Levenshtein distance-The Damerau–Levenshtein distance differs from the classical Levenshtein distance by including transpositions among its allowable operations in addition to the three classical single-character edit operations (insertions, deletions and substitutions).In his semin... | milkshake721/2.1M-wiki-STEM |
Damerau–Levenshtein distance-Definition-To express the Damerau–Levenshtein distance between two strings a and b , a function da,b(i,j) is defined, whose value is a distance between an i -symbol prefix (initial substring) of string a and a j -symbol prefix of b The restricted distance function is defined recursiv... | milkshake721/2.1M-wiki-STEM |
Damerau–Levenshtein distance-Definition-Each recursive call matches one of the cases covered by the Damerau–Levenshtein distance: da,b(i−1,j)+1 corresponds to a deletion (from a to b), da,b(i,j−1)+1 corresponds to an insertion (from a to b), da,b(i−1,j−1)+1(ai≠bj) corresponds to a match or mismatch, depending on whethe... | milkshake721/2.1M-wiki-STEM |
Damerau–Levenshtein distance-Algorithm-Presented here are two algorithms: the first, simpler one, computes what is known as the optimal string alignment distance or restricted edit distance, while the second one computes the Damerau–Levenshtein distance with adjacent transpositions. Adding transpositions adds significa... | milkshake721/2.1M-wiki-STEM |
Damerau–Levenshtein distance-Algorithm-Take for example the edit distance between CA and ABC. The Damerau–Levenshtein distance LD(CA, ABC) = 2 because CA → AC → ABC, but the optimal string alignment distance OSA(CA, ABC) = 3 because if the operation CA → AC is used, it is not possible to use AC → ABC because that would... | milkshake721/2.1M-wiki-STEM |
Damerau–Levenshtein distance-Algorithm-Optimal string alignment distance Optimal string alignment distance can be computed using a straightforward extension of the Wagner–Fischer dynamic programming algorithm that computes Levenshtein distance. In pseudocode: algorithm OSA-distance is input: strings a[1..length(a)], b[... | milkshake721/2.1M-wiki-STEM |
Damerau–Levenshtein distance-Algorithm-for i := 0 to length(a) inclusive do d[i, 0] := i for j := 0 to length(b) inclusive do d[0, j] := j for i := 1 to length(a) inclusive do for j := 1 to length(b) inclusive do if a[i] = b[j] then cost := 0 else cost := 1 d[i, j] := minimum(d[i-1, j] + 1, // deletion d[i, j-1] + 1, /... | milkshake721/2.1M-wiki-STEM |
Damerau–Levenshtein distance-Algorithm-maxdist := length(a) + length(b) d[−1, −1] := maxdist for i := 0 to length(a) inclusive do d[i, −1] := maxdist d[i, 0] := i for j := 0 to length(b) inclusive do d[−1, j] := maxdist d[0, j] := j for i := 1 to length(a) inclusive do db := 0 for j := 1 to length(b) inclusive do k := ... | milkshake721/2.1M-wiki-STEM |
Damerau–Levenshtein distance-Algorithm-It is interesting that the bitap algorithm can be modified to process transposition. See the information retrieval section of[1] for an example of such an adaptation. | milkshake721/2.1M-wiki-STEM |
Damerau–Levenshtein distance-Applications-Damerau–Levenshtein distance plays an important role in natural language processing. In natural languages, strings are short and the number of errors (misspellings) rarely exceeds 2. In such circumstances, restricted and real edit distance differ very rarely. Oommen and Loke ev... | milkshake721/2.1M-wiki-STEM |
Damerau–Levenshtein distance-Applications-DNA Since DNA frequently undergoes insertions, deletions, substitutions, and transpositions, and each of these operations occurs on approximately the same timescale, the Damerau–Levenshtein distance is an appropriate metric of the variation between two strands of DNA. More comm... | milkshake721/2.1M-wiki-STEM |
Damerau–Levenshtein distance-Applications-Fraud detection The algorithm can be used with any set of words, like vendor names. Since entry is manual by nature, there is a risk of entering a false vendor. A fraudster employee may enter one real vendor such as "Rich Heir Estate Services" versus a false vendor "Rich Hier S... | milkshake721/2.1M-wiki-STEM |
Damerau–Levenshtein distance-Applications-Export control The U.S. Government uses the Damerau–Levenshtein distance with its Consolidated Screening List API. | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions for the IP Multimedia Subsystem-The Session Initiation Protocol (SIP) is the signaling protocol selected by the 3rd Generation Partnership Project (3GPP) to create and control multimedia sessions with two or more participants in the IP Multimedia Subsystem (... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions for the IP Multimedia Subsystem-SIP was developed by the Internet Engineering Task Force (IETF) as a standard for controlling multimedia communication sessions in Internet Protocol (IP) networks, working in the application layer of the Internet Protocol Suit... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions for the IP Multimedia Subsystem-The 3GPP, which is a collaboration between groups of telecommunications associations aimed at developing and maintaining the IMS, stated a series of requirements for SIP to be successfully used in the IMS. Some of them could b... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-3GPP requirements for SIP-The 3GPP has stated several general requirements for operation of the IMS. These include an efficient use of the radio interface by minimizing the exchange of signaling messages between the mobile terminal and the network, a minimum session setup ... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-3GPP requirements for SIP-Other requirements involve protocol extensions, such as SIP header fields to exchange user or server information, and SIP methods to support new network functionality: requirement for registration, re-registration, de-registration, event notificat... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-3GPP requirements for SIP-Identification of users for authentication, authorization and accounting purposes. Security between users and the network and among network nodes is a major issue to be addressed by using mutual authentication mechanisms such as private and public... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-3GPP requirements for SIP-Protection of SIP signaling with integrity and confidentiality support based on initial authentication and symmetric cryptographic keys; error recovery and verification are also needed.
Session release initiated by the network (e.g. in case the us... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-Extension negotiation mechanism-There is a mechanism in SIP for extension negotiation between user agents (UA) or servers, consisting of three header fields: supported, require and unsupported, which UAs or servers (i.e. user terminals or call session control function (CSC... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-Caller preferences and user agent capabilities These two extensions allow users to specify their preferences about the service the IMS provides. | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-With the caller preferences extension, the calling party is able to indicate the kind of user agent they want to reach (e.g. whether it is fixed or mobile, a voicemail or a human, personal or for business, which services it is capable to provide, or which me... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-By using the user agent capabilities extension, user agents (terminals) can describe themselves when they register so that others can search for them according to their caller preferences extension headers. For this purpose, they list their capabilities in t... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-Event notification is necessary in the IMS framework to inform about the presence of a user (i.e. "online" or "offline") to others that may be waiting to contact them, or to notify a user and its P-CSCF of its own registration state, so that they know if the... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-To this end, the specific event notification extension defines a framework for event notification in SIP, with two new methods: SUBSCRIBE and NOTIFY, new header fields and response codes and two roles: the subscriber and the notifier. The entity interested i... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-There is also an allow-events header to indicate event notification capabilities, and the 202 accepted and 489 bad event response codes to indicate if a subscription request has been preliminary accepted or has been turned down because the notifier does not ... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-In order to make an efficient use of the signaling messages, it is also possible to establish a limited notification rate (not real-time notifications) through a mechanism called event throttling. Moreover, there is also a mechanism for conditional event not... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-State publication The event notification framework defines how a user agent can subscribe to events about the state of a resource, but it does not specify how that state can be published. The SIP extension for event state publication was defined to allow use... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-The state publication framework defines a new method: PUBLISH, which is used to request the publication of the state of the resource specified in the request-URI, with reference to the event stated in the Event header, and with the information carried in the... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-Call transfer The REFER method extension defines a mechanism to request a user agent to contact a resource which is identified by a URI in the Refer-To header field of the request message. A typical use of this mechanism is call transfer: during a call, the ... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-However, this mechanism is not restricted to call transfer, since the Refer-To header field can be any kind of URI, for instance, an HTTP URI, to require the recipient to visit a web page. | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-Reliability of provisional responses In the basic SIP specification, only requests and final responses (i.e. 2XX response codes) are transmitted reliably, this is, they are retransmitted by the sender until the acknowledge message arrives (i.e. the correspon... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-However, in such an scenario as the IMS framework, it is necessary to extend this reliability to provisional responses to INVITE requests (for session establishment, this is, to start a call). The reliability of provisional responses extension provides a mec... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-Session description updating The aim of the UPDATE method extension is to allow user agents to provide updated session description information within a dialog, before the final response to the initial INVITE request is generated. This can be used to negotiat... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-Preconditions In the IMS framework, it is required that once the callee is alerted, the chances of a session failure are minimum. An important source of failure is the inability to reserve network resources to support the session, so these resources should b... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-The preconditions SIP extension affects both SIP, with a new option tag (precondition) and defined offer/answer exchanges, and Session Description Protocol (SDP), which is a format used to describe streaming media initialization parameters, carried in the bo... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-The SDP offer/answer model using PRACK and UPDATE requests In the IMS, the initial session parameter negotiation can be done by using the provisional responses and session description updating extensions, along with SDP in the body of the messages. | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-The first offer, described by means of SDP, can be carried by the INVITE request and will deal with the caller's supported codecs. This request will be answered by the provisional reliable response code 183 Session Progress, that will carry the SDP list of s... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-The QoS negotiation is supported by the PRACK request, that starts resource reservation in the calling party network, and it is answered by a 2XX response code. Once this response has been sent, the called party has selected the codec too, and starts resourc... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-Identification and charging In the IMS framework it is fundamental to handle user identities for authentication, authorization and accounting purposes. The IMS is meant to provide multimedia services over IP networks, but also needs a mechanism to charge use... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-These header fields are used for a variety of purposes including charging and information about the networks a call traverses: P-Charging-Vector: A collection of charging information, such as the IMS Charging Identity (ICID) value, the address of the SIP pro... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-P-Charging-Function-Address: The addresses of the charging functions (functional entities that receive the charging records or events) in the user's home network. It also may be filled during the establishment of a dialog or as a standalone transaction, and ... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-P-Access-Network-Info: Information about the access technology (the network providing the connectivity), such as the radio access technology and cell identity. It is used to inform service proxies and the home network, so that they can optimize services or s... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-P-Associated-URI: Additional URIs that are associated with a user that is registering. It is included in the 200 OK response to a REGISTER request to inform a user which other URIs the service provider has associated with an address-of-record (AOR) URI.More ... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-P-Profile-Key: The key to be used to query the user database (HSS) for a profile corresponding to the destination SIP URI of a particular SIP request. It is transmitted among proxies to perform faster database queries: the first proxy finds the key and the o... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-Asserted identity The private extensions for asserted identity within trusted networks are designed to enable a network of trusted SIP servers to assert the identity of authenticated users, only within an administrative domain with previously agreed policies... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-The P-Preferred-Identity extension header is also defined, so that a user with several public identities is able to tell the proxy which public identity should be included in the P-Asserted-Identity header when the user is authenticated.
Finally, when privac... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-There exist analogous extension headers for handling the identification of services of users, instead of the users themselves. In this case, Uniform Resource Names are used to identify a service (e.g. a voice call, an instant messaging session, an IPTV strea... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-HTTP digest access authentication using AKA, a more secure version of the previous mechanism for cellular networks that uses the information from the user's smart card and commonly creates two IPsec security associations between the P-CSCF and the terminal.T... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-Then, the P-CSCF adds a security-server header field to the response that contains the same information as the client's but with reference to the P-CSCF. In case there are more than one mechanism, they are associated with a priority value. | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-Finally, the user agent sends a new REGISTER request over the just created secure connection with the negotiated parameters, including a security-verify header field that carries the same contents as the previously received security-server header field. This... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-Media authorization The necessity in the IMS of reserving resources to provide quality of service (QoS) leads to another security issue: admission control and protection against denial-of-service attacks. To obtain transmission resources, the user agent must... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-The private extensions for media authorization link session signaling to the QoS mechanisms applied to media in the network, by defining the mechanisms for obtaining authorization tokens and the P-Media-Authorization header field to carry these tokens from t... | milkshake721/2.1M-wiki-STEM |
SIP extensions for the IP Multimedia Subsystem-SIP extensions-Source-routing mechanisms Source routing is the mechanism that allows the sender of a message to specify partially or completely the route the message traverses. In SIP, the route header field, filled by the sender, supports this functionality by listing a s... | milkshake721/2.1M-wiki-STEM |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.