Function chaining

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OpenStack service function chaining interface

OpenStack service function chaining interface

This work proposes a solution to the problem of managing virtualized network functions (VNFs) in OpenStack 1 . Specifically, it suggests a solution for managing Service Function Chaining. The tools that are currently available are not user friendly, and require the usage of the command line interface (CLI). Furthermore, the administrator has to be familiar with the system, know the commands and the proper sequence in order to achieve the desired configuration. Any large scale network configuration is impractical as it requires a lot of human interaction with a somewhat exhausting command line interface. However this can be simplified and somewhat automated by creating scripts that configure the whole network, but it is only helpful in the case of initial configuration of the network. Even though it is not suitable when some parts of the network have to be reconfigured it is still used because of a lack of alternatives. This approach isn't changing the paradigm, with the administrator still using the command line interface. The other approach for managing networks in OpenStack is via a graphical user interface (GUI). By taking advantage of available APIs it should be possible to create a graphical user interface for managing virtualized network functions. A GUI solution for managing networks in OpenStack already exists, but it only provides basic functionality, e.g., virtual networks and subnetworks provisioning. It does not support Service Function Chaining management. A graphical user interface for Service Function Chaining
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Policy-driven vCPE through dynamic network service function chaining

Policy-driven vCPE through dynamic network service function chaining

Abstract—Virtual CPEs address the low agility, slow time-to- market and high costs (of development, deployment and support) that are inheritable to traditional CPEs. They take advantage of the economics of Cloud Computing and the ability to run Virtual Network Functions in a general computing platform to build richer services, with faster development and deployment times, all whilst reducing costs. When coupled together with Service Function Chaining and the ability to build/enter chains dynamically, an opportunity arises to enhance this system by making the whole vCPE’s functionality policy-driven. We will start by constructing the vCPE within an OpenSource cloud platform (OpenStack), which will have dynamic SFC capablities added through own extensions. Then we will make the traffic classification through a DPI (ntop’s nDPI), which will mark flows according to a configurable policy (REST interface) that will determine which service chain that flow must follow. Some virtual functions within a chain may trigger events (such as reaching the traffic quota for a certain service), being the policy immediately enforced at the VNFs and an “on-the-fly” policy change possible through the REST interface (for instance, change the throttle amount to a given application traffic). A live Proof-of-Concept was made which allowed real devices to connect to the vCPE.
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SFC path tracer : a troubleshooting tool for service function chaining

SFC path tracer : a troubleshooting tool for service function chaining

Network operators spend significant effort in ensuring that network meets their intent behavior [21], with the lack of tools to check network functions in the path. The increasing scale and dynamism that NFV introduces add, even more, challenges to detect possible misconfiguration. OAM for SFC [12] provides a reference framework for Operations, Administration and Maintenance (OAM) for Service Function Chaining (SFC). It indicates the aspects of SFC that should be monitored. The monitoring element should have capabilities to monitor aware and unaware service functions, service function performance, service functions forwarders and the classifier. OAM for SFC highlights monitoring functions such as connectivity, continuity, trace and performance measurements. Packet trace function enables the detection of above common problems. Once a packet trace is generated, a path can be monitored to detect connectivity and performance issues such as packet losses and overloaded SFs. Packet traces give informations such as prof of transit of network packets and then pinpointing the problematic location when traffic is delayed or does not reach its destination.
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Service function chaining for NFV in cloud environments

Service function chaining for NFV in cloud environments

Given the vDHCP also performs session control with the DHCP protocol (through the module that follows in the next subsection), it is required to provide a way outside of the port creatio[r]

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Programmable, expressive, scalable, and agile service function chaining for edge data centers

Programmable, expressive, scalable, and agile service function chaining for edge data centers

To enable the integration of KAR’s fast failure reaction mechanism in our SFC proto- type, we developed a simple control plane application that causes link failures and makes port failure information available to the dataplane by populating a table of faulty ports in affected switches. In addition, we modified the program of the core nodes to check this table before transmitting the packet to the output port that was obtained via the modulo operation. If there is a hit, the packet is randomly deflected to one of the other healthy ports. Otherwise, the packet is transmitted normally. The generation of a ran- dom value within a interval is provided by v1model and could also be replaced by a hash function if the objective is to always select the same port per flow. More sophisticated mechanisms for failure detection and other P4 targets can be explored in future works [ Cascone et al. 2017 ], as this is not the scope of this thesis.
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Composição de serviços em network function virtualization

Composição de serviços em network function virtualization

Buscando a padronização de conceitos, criação de uma arquitetura e implementação de protocolos, a Internet Engineering Task Force (IETF) criou o Service Function Chaining Work Group (IETF SFCWG) 1 com a finalidade de integrar a comunidade acadêmica junto aos desafios existentes e às questões abertas referentes a SFC. A Figura 2.3 ilustra a representação de um serviço de rede fim-a-fim. A camada física é formada pelos nós físicos representadas pelos vértices de A a I. Enquanto que SF-1, SF-2 e SF-3 estão conectadas entre si através de links virtuais, camada virtual, formando uma cadeia abstrata de SFs. Portanto, sendo SC um serviço oferecido por um PST, SC = {SF-1, SF-2, SF-3} representa o encadeamento de funções necessárias para que o serviço SC ocorra.
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The Conditional Sequence Information Function

The Conditional Sequence Information Function

Currently many researchers are investigating bioinformation using very complex mathematical functions. Of particular interest to us is the information function defined by Shannon (1948). Both Khinchin (1957) and Shannon (1948) have investigated the properties of this information function. Brown (1976) and Gray and Davidson (1970) defined the entropy function of dynamical systems and investigated its properties. Tok (1986) defined the fuzzy information function and investigated its properties. Moreover, Newton (1970a; 1970b); Walters (1975; 2000) and Guzide (1990) (in Turkish) defined conditional sequence entropy and sequence entropy functions and investigated their properties.
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Function theory for fractional Dirac operators

Function theory for fractional Dirac operators

The function theory for null-solutions of the Dirac operator defines the so-called classic Clifford analysis, or the theory of monogenic functions, that is, solutions of the mass-less Dirac operator. The motivation for studying this subject is due the fact that Clifford analysis, among other things, represents one of the most remarkable field of modern mathematics with a higher dimensional generalization of Complex Analysis. These null-solutions, also called monogenic functions, replace the notion of a holomorphic function, i.e. the Dirac operator D on R d , a conformally invariant first-order differential operator, plays the same role in classical Clifford analysis as the Cauchy-Riemann operator ∂ z does in the complex analysis.
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Gene function diversification upon duplication

Gene function diversification upon duplication

Gene duplication facilitates the evolution of new gene functions by relaxing evolutionary pressure on the duplicates. Besides pseudogenization, three outcomes can occur: both copies keep the ancestral function (e.g., Positive dosage); one maintains the ancestral function and the other gains a new function (Neofunctionalization); ancestral functions are partitioned between the copies (Subfunctionalization). Cis-regulatory evolution, mainly enhancers, has gained weight in explaining this process, due to its lesser pleiotropic nature relative to protein evolution. However, knowledge on the cis-regulatory changes responsible for duplicate functional diversification is still lacking. In our lab, we use clusters III and V of the Ly6 gene family of Drosophila melanogaster, which underwent sequential duplications during the dipteran evolution, as a gene duplication evolutionary model. At each duplication event, one of the duplicates maintained the ancestral expression pattern while the other acquired novel expression domains (Neofunctionalization). CG9336 and CG9338, found in D. melanogaster, are the most recent duplicates, having already divergent expression patterns. An interesting fact is that expression divergence is not only seen between these duplicates and the unduplicated orthologue found in Ceratitis capitata, but also between duplicates in different species of Drosophilids. Given the high frequency of duplication events within a short time-scale observed in these genes, they are a good model to study cis-regulatory evolution.
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Monounsaturated fats and immune function

Monounsaturated fats and immune function

Animal studies suggest that olive oil is capable of modulating func- tions of cells of the immune system in a manner similar to, albeit weaker than, fish oils. There is some evidence that the effects of olive oil on immune function in animal studies are due to oleic acid rather than to trace elements or antioxidants. Importantly, several studies have demonstrated effects of oleic acid-containing diets on in vivo immune responses. In contrast, consumption of a monounsaturated fatty acid (MUFA)-rich diet by humans does not appear to bring about a general suppression of immune cell functions. The effects of this diet in humans are limited to decreasing aspects of adhesion of peripheral blood mononuclear cells, although there are trends towards decreases in natural killer cell activity and proliferation. The lack of a clear effect of MUFA in humans may be attributable to the higher level of monounsaturated fat used in the animal studies, although it is ulti- mately of importance to examine the effects of intakes which are in no way extreme. The effects of MUFA on adhesion molecules are poten- tially important, since these molecules appear to have a role in the pathology of a number of diseases involving the immune system. This area clearly deserves further exploration.
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The health production function revisited

The health production function revisited

The present study aimed at widening the knowledge on health production factors. Particularly, we were concerned in comprehending how social network contacts and the share of liquid wealth interact in the production of health, for individuals aged 50 years or more. A novel extension of the Grossman model, which encompasses the role of social network interactions as well as that of wealth portfolio’s composition, predicts that both the time allocated to social networks and the share of liquid wealth positively impact the production of health. In order to empirically test these hypotheses, we estimated the health production function with a recursive system of equations, which allowed us to control for potential sources of endogeneity associated with the main variables of interest – social network contacts and share of liquid wealth – as well as for the endogeneity of health care demand. The empirical results endorse the theoretical preditions and unveil a substitutability relation between social networks and the share of liquid wealth in the production of health.
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Regucalcin evolution and gene function

Regucalcin evolution and gene function

It should be noted that the accumulation of mutations in genes resulting from duplication events, is the main source of new genes appearance. Indeed, an entirely redundant duplicate copy will not be kept in a genome for long periods, due to the existence of deleterious mutations, which accumulate over time and turn that gene nonfunctional (Zhang, 2003). A functional divergence is needed between duplicates for their long-term genome retention (He and Zhang, 2005). The neofunctionalization (NF) hypothesis of Ohno, (2014) says that after duplication, one descendant gene retains the ancestral function, whereas the other acquires new functions, experiencing a period of complete functional relaxation, behaving like a pseudogene. As an alternative to this theory, there is the subfunctionalization (SF), which implies that duplicate genes experience degenerate mutations that reduce their joint levels and patterns of activity to that of the single ancestral gene (He and Zhang, 2005).
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Certain Aspects of Univalent Function with Negative Coefficients Defined by Bessel Function

Certain Aspects of Univalent Function with Negative Coefficients Defined by Bessel Function

Many important functions in applied sciences are defined via improper integrals or series (or infïnite products). The general name of these important functions are called special functions. Bessel functions are important special functions which are playing the important role in studying solutions of differential equations. Especially, the linear PDE describing various chemical transfer processes, allow the exact solution expressed in terms of one special kind of Bessel’s functions and they are associated with a wide range of problems in important areas of mathematical physics, modelling of transfer processes in chemical engineering as well as in the related fields like hydrodynamics, heat transfer, diffusion, bioprocesses and so on. By using the method of seperation of variables, exact solution in terms of Bessel function can be used to calculate several important parameters which are needed in design and construction of chemical engineering apparatuses and equipment like heat exchangers and their components. Typical example for the efficiency calculation is applied in Brazilian powdered milk plant [11]. In another case when the Bessel functions arises is heat transfer modelling which considered in [6]. Here the problem of cross-flow streaming of heated object with large value of length to diameter ratio (like thermoanemometer) is solved for small Pe numbers using the theory of analytic functions.
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Gut form and function

Gut form and function

houses a complex microbiota, which out-number host eukaryotic cells ten-fold (Shanahan 2002). The gas- trointestinal tract is responsible for nutrient absorption and digestion, excretion of non-digestible material and, seemingly paradoxically, excluding the entry of lumen- derived unprocessed dietary or microbial antigen and mi- croorganisms into the mucosa. The efficient functioning of the gut requires the coordinated activity of structural/ stromal cells and regulatory elements (i.e. neuroendocrine and immune-derived factors) (Perdue & McKay 1994). Similarly, while it is instinctive to consider the microbiota as inherently bad and potentially pathogenic, the former is not true as it is quite clear that a normal intestinal flora is a requirement for normal intestinal function (Rook & Stanford 1998). For instance, intestinal morphology of gnotobiotic-raised animals is different from animals main- tained under conventional housing, and bacteria-liberated short-chain fatty acids are an important energy source for colonocytes.
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Swallowing function in advanced age

Swallowing function in advanced age

Early results reflect previ- ous studies of age-related swallowing changes between dichotomous younger (<65 years old) and older age groups (e.g., increased pharyngeal transit times, [r]

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Structure-function relationship of immunostimulatory polysaccharides

Structure-function relationship of immunostimulatory polysaccharides

The previous search in the Scopus Database revealed that glucans, mannans, pectic polysaccharides, arabinogalactans, fucoidans, sulfated galactans, hyaluronans, fructans, and xylans are the most studied types of polysaccharides. In order to find structure-function relationships, a further database search was performed adding the structural feature topic to the previous ones (“polysaccharides AND (immuno OR immune OR immunostimulatory OR immunomodulatory) AND type of polysaccharide”). From this search it was found that in addition to the type of polysaccharide, conformation, molecular weight, presence of functional groups like acetyl and sulfate groups, charge and degree of branching are connected with the immuno topic (Figure 1.14). It can be noticed that some structural features have more relevance in some type of polysaccharides than in another’s and that in almost all type of polysaccharides the number of papers associated to a structural feature is lower than the number of papers without assigned structural features, supporting the lack of structure-function relationships. Furthermore, the combination of several structural features may impact the resulting immunostimulatory activity in different ways.
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LIVER FUNCTION TESTS AFTER HALOTHANE ANAESTHESIA

LIVER FUNCTION TESTS AFTER HALOTHANE ANAESTHESIA

countries, owing to its low cost, this study was conducted to compare liver function tests before and after Halothane anaesthesia. Results - Slight increase in serum bilirubin, SGOT, SGPT, serum calcium and slight rise in eosinophil count was found in both groups post-operatively, which was statistically not significant except the rise in SGPT levels in immediate post-operative period which was significant in both groups. Conclusion – Halothane anaesthesia with 100% or 40 % oxygen in adults does produce a slight alteration in Liver function tests with no correlation with duration of anaesthesia and gender. However, there was significant rise in SGPT in immediate post-operative period.
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HOXB genes function in Breast Cancer

HOXB genes function in Breast Cancer

After successful validation of HOXB7 knockdown in mRNA expression it would be likely to assume that siHOXB7-transfected cells would acquire the ability to form aggregates. This assumption is based on the preliminary results from our lab suggesting an increase on CDH1 expression concomitant with the decrease of HOXB7 expression in MDA-MB-231 cells. Thus, we next performed an aggregation assay using MDA-MB-231 cells non- manipulated (WT) or transfected with siHOXB7 or siRNA negative control (siC-) (Fig. 11). In this assay we used the MB2 antibody to block the function of CDH1 and, therefore, make evident the specificity of the aggregation effect. As positive control we used MCF-7 WT cells, which characteristically present compact aggregation as spheroids that grow larger with time. With the incorporation of MB2, MCF-7 cells grew as adhere clumps losing their ability to form spheroids. In contrast, MDA-MB-231 cells transfected with a negative control siRNA (siC-) with and without MB2 did not show any changes when compared to MDA-MB- 231 WT cells. The MDA-MB-231 siHOXB7-transfected cells did not display a change in the rate of aggregate formation in comparison to MDA-MB-231 siC- cells in any time point. Similarly, the MB2 added caused no effect in the aggregation ability of the cells.
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Lifestyle impact on human sperm function

Lifestyle impact on human sperm function

After being release to the seminiferous lumen, spermatozoa are conducted through the rete testis to the epididymis. The transport to the epididymis is assisted by the pressure exerted from sperm mass production in the testis, fluid secretion from Sertoli cells, contractive movements from testicular capsule and myoid layer and cilia movements present in epithelium of the efferent ducts (Sutovsky & Manandhar 2006). Epididymis is composed of three different regions (caput, corpus and cauda), each one with a diverse function. Early and late maturational events occur in caput and corpus region, respectively, and cauda region functions as a local to storage mature spermatozoa (Cornwall & Horsten 2007). During migration from caput to cauda region, spermatozoa suffer biochemical, morphological and physiological alterations to become motile and mature (fertile) spermatozoa. Changes in spermatozoa include modifications in plasmatic membrane, acquirement of proteins released by epididymal epithelium and phosphorylation of specific proteins important for maturational steps (Toshimori 2003; Cornwall & Horsten 2007; Cornwall 2009).
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Motion Control Function Blocks for IEC61131-3

Motion Control Function Blocks for IEC61131-3

In the development of the project, within the industrial automation, there are numerous deve- lopment environments launched by various brands of PLCs. But they have some disadvantages such as the fact that they are paid and they have various restrictions on the level of use platform and compatibility. Due to these factors, we used the Beremiz, software created by Lolitech. This envi- ronment is open-source, free, multiplatform and follows the restrictions imposed by IEC 61131-3. In order to validate and evaluate the Function Blocks created, numerous tests that verified if they communicate properly with the engine encouraging their movement were performed.
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