A Mobile Ad Hoc Network (MANET) is a shared wireless network without any infrastructure, consisting of mobile nodes connected by wireless links. The nodes are free to move and organize themselves arbitrarily. The nodes in the network are therefore depending on each other in order to communicate over multiple hops. Due to the physical characteristics of wireless networks, the channel is time-varying, which makes it hard to both predict and sustain a bit rate level. The nodes’ mobility causes topology changes, and further load and capacity variations. Traditional usage areas are battlefield and disaster areas, while new areas like extended network coverage and gaming are emerging. Quality of Service (QoS) is needed in every network in order to differentiate traffic with different performance requirements, e.g. voice and e-mail applications. Providing QoS in wireless environments with varying conditions is complex, and hard guarantees can not be given. Consequently, the aim is to give differentiated treatment to traffic with different performance requirements. In addition, we can not study the MANET without considering fixed networks. Communication with fixed networks is important, for example by accessing the Internet. In this thesis the Differentiated Services (DiffServ) architecture is applied and adapted to MANETs. Using the same QoS architecture will ease the transition between the wireless and wired domain. But the special characteristics of wireless networks require modifications to the original DiffServ architecture. In investigations there was found restrictions on the number of classes to use, and this number was dependent on the type of traffic in the network. A QoS architecture based on the DiffServ framework is proposed, with an admission control based on the concept of shadow classes, and Explicit Congestion Notification (ECN) to avoid congestion. New flows are tested in a shadow class before getting admission to the network and its designated class. The shadow class has the same scheduling properties as the designated class, but is differentiated by a higher drop probability in the buffers. Both the admission control and ECN are thus build on the same principle by controlling the load from probabilistic functions in the buffers, and are studied to find their individual and combined effects. In wireless environments the probability of a packet loss increases with the number of hops, which gives services an unpredictable performance for users. A predictable service, independent of number of hops, is provided by scheduling based on the path information; the packets are differentiated based on the number of hops made or left to make, increasing the predictability at the cost of performance.

Der probiotische Stamm E. coli Nissle 1917 ist ein Fäkalisolat, das in der Medizin traditionell zur Behandlung verschiedener gastrointestinaler Erkrankungen eingesetzt wird. Durch erfolgversprechende klinische Studien zur Remissionserhaltung bei Colitis ulcerosa, bei denen EcN als therapeutische Alternative zur Standardmedikation eingesetzt wird, ist das Interesse an den Wirkmechanismen von Probiotika stark gestiegen. EcN gehört derzeit zu den am besten untersuchten Probiotika. Einige Wirkmechanismen konnten dadurch schon aufgeklärt werden. So sind vermutlich Strukturkomponenten und stammspezifische Syntheseleistungen an der Ausprägung des probiotischen Phänotyps von EcN beteiligt. Schlüssige Konzepte, die über Gene, Genprodukte und molekulare Mechanismen den probiotischen Effekt von EcN erklären, fehlen bislang. Im Rahmen dieser Arbeit wird das Genom von EcN analysiert und auf der Basis der Genomsequenz mit anderen E. coli-Stämmen verglichen. Mit Hilfe einer Promotor-Reporter-Fusionsbibliothek (Promotorbank) werden intestinal in vivo regulierte Gene identifiziert und dadurch neue Ansätze zur Untersuchung der probiotischen Eigenschaften von EcN geschaffen. Die Grundlage für die molekulare Analyse von EcN ist die manuelle Nachannotation seines sequenzierten Genoms. Die EcN-Sequenz wird mit 13 weiteren annotierten E. coli-Sequenzen verglichen. Nach dieser Analyse kodiert EcN derzeit 121 stammspezifische Gene. Die Genomstruktur ist mit den enthaltenen genomischen Inseln und Prophagen dem Genom des uropathogenen E. coli CFT073 sehr ähnlich. Mit wenigen Ausnahmen kodiert EcN alle in E. coli CFT073 vorhandenen Virulenz- und Fitnessfaktoren, so dass auf der Nukleotidebene die nahe Verwandschaft dieser beiden Stämme bestätigt werden kann. Zudem kann gezeigt werden, dass EcN in artifiziellen Systemen wie der Zellkultur oder gnotobiotischen Mäusen ein pathogenes Potenzial hat, obgleich die Kolonisierungsfähigkeit pathogener Bakterien durch Inkubation mit EcN herabgesetzt wird. Eine wichtige Rolle bei der Besiedlung des Intestinaltrakts und der Immunstimulation von Darmepithelzellen spielt auch die globale Regulation der Genaktivität bei EcN durch den alternativen Sigma-Faktor RpoS, der im Gegensatz zu rpoS-Deletionsmutanten zu einer gesteigerten mRNA-Expression des Tight-junction Proteins ZO-1 führt. Des Weiteren führte die Untersuchung von EcN-Deletionsmutanten zu der Schlussfolgerung, dass einige genomische Inseln für Eigenschaften, die das probiotische Verhalten erklären können, eine Rolle spielen. Durch den Einsatz einer Promotorbank von EcN in konventionellen und gnotobiotischen Mäusen werden erstmalig Sequenzen von intestinal in vivo aktiven Promotoren identifiziert. Der Aufbau eines Promotor-Reportergen-Assays mit dem Biolumineszenz erzeugenden luxCDABE-Operon ermöglichte die Untersuchung ausgewählter Promotoren in vitro. Mit einem In Vivo Imaging System (IVIS) kann in weiteren Experimenten die Aktivität dieser Promotoren in lebenden Mäusen untersucht werden. Im Rahmen dieser Arbeit wird gezeigt, dass EcN kein vollkommen harmloser probiotischer Stamm ist. Weitere Informationen über EcN sind dehalb wichtig für eine optimierte Anwendung als Therapeutikum. Die molekulare Analyse ist somit eine unbedingt notwendige Grundlage für weiterführende Untersuchungen der Eigenschaften von EcN, die für seinen probiotischen Charakter verantwortlich sind. / The probiotic E. coli Nissle 1917 is a fecal isolate which is traditionally used for treatment of various gastrointestinal disorders. In clinical trials where EcN was used as therapeutic alternative for remission maintenance of ulcerative colitis compared to standard medication, promising results led to an increased interest in probiotics. Today, EcN is one of the best studied probiotics. Therefore, several mechanisms of action could be enlightened. Structural components and strain-specific products are responsible for its probiotic effects. But conclusive concepts about genes, gene products and molecular mechanisms that really contribute to the probiotic character of EcN have not been offered so far. In order to create new possibilities to elucidate the probiotic traits of EcN the genome is analysed by taking this as a basis for comparison to other E. coli genomes and identification of intestinal in vivo regulated genes using a promoter-trap-library. The sequenced EcN genome is annotated and compared to 13 other so far annotated E. coli genomes. Concerning these analyses EcN encodes 121 strain-specific genes. The genome structure including the genomic islands and prophages is highly homolog to the uropathogenic E. coli CFT073. EcN encodes most of the virulence and fitness factors that are present in E. coli CFT073. Therefore, the close relationship of these two strains is confirmed at nucleotide level. Furthermore, it is shown that in artificial systems like cell culture assays and gnotobiotic mice EcN reveals a pathogenic potential although EcN is able to decrease colonization efficiency of pathogenic bacteria. The alternative sigma factor RpoS that is responsible for global regulation and activity of several genes seems to play an important role during colonization of EcN in the intestine and its immunostimulatory effects on intestinal epithelial cells. Investigation of EcN-deletion mutants lacking genomic islands and prophages lead to the conclusion that some genomic islands may play a role for specific probiotic traits. This is the first time where a promoter-trap-library was used in conventional and gnotobiotic mice for collection of intestinal in vivo active promoters. Constructing and establishing a promoter-reporter gene assay with the bioluminescent luxCDABE operon made the investigation of selected promoters in vitro possible as well as establishing a bioluminescence assay using an In Vivo Imaging System (IVIS) for investigation of promoter activity in living mice. In this research project was shown that EcN is not a completely harmless probiotic. The genome structure and regulatory mechanisms of gene expression are the strain’s molecular traits that lead to probiotic activity and immunostimulatory effects. Therefore, the molecular analyses presented here, together with the complete genome sequence, are a basis for further investigations of mechanisms that are responsible for the probiotic effects of EcN.

Der probiotische Stamm E. coli Nissle 1917 ist ein Fäkalisolat, das in der Medizin traditionell zur Behandlung verschiedener gastrointestinaler Erkrankungen eingesetzt wird. Durch erfolgversprechende klinische Studien zur Remissionserhaltung bei Colitis ulcerosa, bei denen EcN als therapeutische Alternative zur Standardmedikation eingesetzt wird, ist das Interesse an den Wirkmechanismen von Probiotika stark gestiegen. EcN gehört derzeit zu den am besten untersuchten Probiotika. Einige Wirkmechanismen konnten dadurch schon aufgeklärt werden. So sind vermutlich Strukturkomponenten und stammspezifische Syntheseleistungen an der Ausprägung des probiotischen Phänotyps von EcN beteiligt. Schlüssige Konzepte, die über Gene, Genprodukte und molekulare Mechanismen den probiotischen Effekt von EcN erklären, fehlen bislang. Im Rahmen dieser Arbeit wird das Genom von EcN analysiert und auf der Basis der Genomsequenz mit anderen E. coli-Stämmen verglichen. Mit Hilfe einer Promotor-Reporter-Fusionsbibliothek (Promotorbank) werden intestinal in vivo regulierte Gene identifiziert und dadurch neue Ansätze zur Untersuchung der probiotischen Eigenschaften von EcN geschaffen. Die Grundlage für die molekulare Analyse von EcN ist die manuelle Nachannotation seines sequenzierten Genoms. Die EcN-Sequenz wird mit 13 weiteren annotierten E. coli-Sequenzen verglichen. Nach dieser Analyse kodiert EcN derzeit 121 stammspezifische Gene. Die Genomstruktur ist mit den enthaltenen genomischen Inseln und Prophagen dem Genom des uropathogenen E. coli CFT073 sehr ähnlich. Mit wenigen Ausnahmen kodiert EcN alle in E. coli CFT073 vorhandenen Virulenz- und Fitnessfaktoren, so dass auf der Nukleotidebene die nahe Verwandschaft dieser beiden Stämme bestätigt werden kann. Zudem kann gezeigt werden, dass EcN in artifiziellen Systemen wie der Zellkultur oder gnotobiotischen Mäusen ein pathogenes Potenzial hat, obgleich die Kolonisierungsfähigkeit pathogener Bakterien durch Inkubation mit EcN herabgesetzt wird. Eine wichtige Rolle bei der Besiedlung des Intestinaltrakts und der Immunstimulation von Darmepithelzellen spielt auch die globale Regulation der Genaktivität bei EcN durch den alternativen Sigma-Faktor RpoS, der im Gegensatz zu rpoS-Deletionsmutanten zu einer gesteigerten mRNA-Expression des Tight-junction Proteins ZO-1 führt. Des Weiteren führte die Untersuchung von EcN-Deletionsmutanten zu der Schlussfolgerung, dass einige genomische Inseln für Eigenschaften, die das probiotische Verhalten erklären können, eine Rolle spielen. Durch den Einsatz einer Promotorbank von EcN in konventionellen und gnotobiotischen Mäusen werden erstmalig Sequenzen von intestinal in vivo aktiven Promotoren identifiziert. Der Aufbau eines Promotor-Reportergen-Assays mit dem Biolumineszenz erzeugenden luxCDABE-Operon ermöglichte die Untersuchung ausgewählter Promotoren in vitro. Mit einem In Vivo Imaging System (IVIS) kann in weiteren Experimenten die Aktivität dieser Promotoren in lebenden Mäusen untersucht werden. Im Rahmen dieser Arbeit wird gezeigt, dass EcN kein vollkommen harmloser probiotischer Stamm ist. Weitere Informationen über EcN sind dehalb wichtig für eine optimierte Anwendung als Therapeutikum. Die molekulare Analyse ist somit eine unbedingt notwendige Grundlage für weiterführende Untersuchungen der Eigenschaften von EcN, die für seinen probiotischen Charakter verantwortlich sind. / The probiotic E. coli Nissle 1917 is a fecal isolate which is traditionally used for treatment of various gastrointestinal disorders. In clinical trials where EcN was used as therapeutic alternative for remission maintenance of ulcerative colitis compared to standard medication, promising results led to an increased interest in probiotics. Today, EcN is one of the best studied probiotics. Therefore, several mechanisms of action could be enlightened. Structural components and strain-specific products are responsible for its probiotic effects. But conclusive concepts about genes, gene products and molecular mechanisms that really contribute to the probiotic character of EcN have not been offered so far. In order to create new possibilities to elucidate the probiotic traits of EcN the genome is analysed by taking this as a basis for comparison to other E. coli genomes and identification of intestinal in vivo regulated genes using a promoter-trap-library. The sequenced EcN genome is annotated and compared to 13 other so far annotated E. coli genomes. Concerning these analyses EcN encodes 121 strain-specific genes. The genome structure including the genomic islands and prophages is highly homolog to the uropathogenic E. coli CFT073. EcN encodes most of the virulence and fitness factors that are present in E. coli CFT073. Therefore, the close relationship of these two strains is confirmed at nucleotide level. Furthermore, it is shown that in artificial systems like cell culture assays and gnotobiotic mice EcN reveals a pathogenic potential although EcN is able to decrease colonization efficiency of pathogenic bacteria. The alternative sigma factor RpoS that is responsible for global regulation and activity of several genes seems to play an important role during colonization of EcN in the intestine and its immunostimulatory effects on intestinal epithelial cells. Investigation of EcN-deletion mutants lacking genomic islands and prophages lead to the conclusion that some genomic islands may play a role for specific probiotic traits. This is the first time where a promoter-trap-library was used in conventional and gnotobiotic mice for collection of intestinal in vivo active promoters. Constructing and establishing a promoter-reporter gene assay with the bioluminescent luxCDABE operon made the investigation of selected promoters in vitro possible as well as establishing a bioluminescence assay using an In Vivo Imaging System (IVIS) for investigation of promoter activity in living mice. In this research project was shown that EcN is not a completely harmless probiotic. The genome structure and regulatory mechanisms of gene expression are the strain’s molecular traits that lead to probiotic activity and immunostimulatory effects. Therefore, the molecular analyses presented here, together with the complete genome sequence, are a basis for further investigations of mechanisms that are responsible for the probiotic effects of EcN.

<p>Målet med projektet var att skapa en applikation för Ericsson AB R&D som kan hjälpa till att analysera datatrafiken i deras nätverk (ECN). Det finns tre stycken accesspunkter till ECN som skyddas av brandväggar. Alla datauppkopplingar genom brandväggarna lagras dygnvis i loggar. Genom loggarna kan obehörig trafik upptäckas. Ett verktyg som analyserar brandväggsloggarna underlättar arbetet.</p><p>Resultatet av mitt examensarbete är en applikation som är skriven i Perl. Programmeringsspråket Perl valdes för dess effektiva texthantering. Programmet exekveras genom terminalen (Solaris) / kommandoraden (Windows). De två viktigaste funktionerna är Searchlog och Check. Searchlog hanterar sökning av IP-adresser och Check kontrollerar att det inte finns några säkerhetsöverträdelser i brandväggsloggarna. Funktionerna har konstruerats så att största vikt är lagd på exekveringstiden och korrekt utdata.</p><p>Slutsatsen av arbetet med brandväggsloggar är att det kräver testning för att få programmet att uppnå optimalt resultat. Perls reguljära uttryck var till stor hjälp i mitt arbete. De är bra vid behandling av stora mängder text. Minnesanvändningen kanske kan göras effektivare. Eftersom att exekveringstiden prioriterades kom det i andra hand.</p> / <p>The goal of this project was to construct an application that can analyze the traffic through the network (ECN) at Ericsson. There are three accesspoints to ECN protected by firewalls. The connections through the firewalls are logged daily. With the help from firewall logs unauthorized access can be found. A tool which analyzes the logs is therefore needed.</p><p>The program is made in the computer language Perl. Perl was chosen because of its superior text handling capabilities. The application is executed through the terminal/command line. The two most important functions are Searchlog and Check. Searchlog handles the IP-searching and the Check function searches for unauthorized connections in the firewall logs. Execution time and data integrity were the main goals that were strived for.</p><p>My conclusion is that working with firewall logs requires a lot of testing to achieve the best result. I realized that regular expressions is the easiest and most powerful tool to use when working with large amounts of text. Since the speed was prioritized and not memory usage there is room for memory improvement.</p>

Durchfallerkrankungen unterschiedlicher Genese sind eine der häufigsten Vorstellungsgründe in der Kleintierpraxis. Neben den Folgen für das betroffene Tier selbst, ist die Erkrankung oft auch eine enorme Belastung für den Besitzer. Im Rahmen der vorliegenden Arbeit wurden erste grundlegende Erkenntnisse zum Einsatz des probiotisch wirksamen Escherichia coli Stamm Nissle 1917 (EcN) als Arzneimittel bei gastrointestinalen Störungen mit der Leitsymtomatik "Diarrhöe" bei der Tierart Hund gewonnen. Aus den vorliegenden Ergebnissen lässt sich ableiten, dass EcN in der Lage ist, die Magen-Darm-Passage bei solch erkrankten Hunden lebensfähig zu überwinden. Es wurde weiter gezeigt, dass EcN einem Placebo in der Behandlung eines akuten Durchfalls bei der Tierart Hund signifikant überlegen ist.

INTRODUCCIÓN. La enterocolitis necrotizante (ECN) es una enfermedad digestiva neonatal grave, multifactorial y de etiología diversa, caracterizada por inflamación e isquemia del intestino delgado y colon que progresa hacia la necrosis transmural y perforación. La prevalencia se sitúa alrededor de uno a tres por cada mil recién nacidos vivos siendo mayor en prematuros con un peso inferior a 1500 gramos (g), es decir de muy bajo peso al nacer. HIPÓTESIS. Los cambios de flujo mesentérico medidos por Ecografía Doppler color tienen correlación con las lesiones intestinales macroscópicas y microscópicas en un modelo experimental de ECN. MATERIAL Y MÉTODO. Se estudiaron 2 grupos de 10 (control: 1 / isquemia: 2) y un grupo de 16 (reperfusión: 3) ratas (Sprague-Dawley) de ambos sexos de 17 días de vida con un peso promedio de 21 a 36 g. Las variables ecográficas a comparar fueron: velocidad sistólica máxima (VSM), velocidad media (Vm), flujo diastólico (FD), pico de flujo diastólico reverso (PFDR), índice de pulsatilidad (IP), índice de resistencia (IR) y proporción o índice sístole/diástole (S/D). Las variables de histología a comparar fueron: lesión intestinal (escala de Wallace/Keenan/ Chiu delgado), altura media de vellosidades (AMV), hipertrofia glandular, células caliciformes y mitosis. El modelo de isquemia-reperfusión consiste en clampar la arteria mesentérica superior en su raíz por 60 minutos (grupo 2) y reperfundir por 24 horas (grupo 3). La ecografía intra-abdominal se practico en los grupos 1, 2 y 3 previo al sacrificio. Tras la necropsia se procede a identificar el intestino delgado y grueso para tomar biopsias, las mismas que serán procesadas en hematoxilina-eosina para su estudio microscópico. El estudio descriptivo fue expresado en mediana (rangos). De los resultados significativos a la Prueba de Kruskal-Wallis se realizó la comparación mediante la Prueba U-Mann-Whiney y la correlación de rangos de Sperman. Posteriormente en el caso de encontrar una correlación significativa se realizó el estudio de regresión no lineal. Consideramos significativo una p<0,01. RESULTADOS. Las variables ecográficas y de anatomía patológica que tienen un grado de asociación significativo (p<0,01) fueron: la VSM, el IP y S/D (ecografía Doppler color) señalando una relación con la escala de Wallace/Keenan, promedio de Chiu en el intestino delgado, AMV, hipertrofia glandular del intestino grueso y células caliciformes del intestino grueso. El grupo 3 comparado con los grupos 1 y 2, la VSM, IP y S/D encontró 5 asociaciones significativas (p<0,01) las cuales guardan relación con escala macroscópica de Wallace/Keenan, la escala microscópica de Chiu delgado, la AMV el porcentaje de hipertrofia glandular del intestino grueso y el número de células caliciformes de intestino grueso. CONCLUSIONES. El modelo de isquemia - reperfusión intestinal en la rata de 17 días de vida logra unas lesiones histopatológicas similares a las de la enterocolitis necrotizante descritas en el recién nacido humano. La velocidad sistólica máxima (VSM) y los índices de resistencia vascular (pulsatilidad [IP] - sístole/diástole [S/D]) medidos por Ecografía Doppler color en la arteria mesentérica superior de rata neonata se encuentran aumentados en la ECN. Existe una correlación directa entre la VSM, el IP y S/D y el grado de lesión intestinal macroscópico (Wallace/Keenan) y microscópico (Chiu). Existe una correlación inversa entre la VSM, el IP y S/D y la altura media de vellosidades (AMV). Existe una correlación directa entre la VSM, el IP y S/D y la hipertrofia glandular en el colon. Existe una correlación inversa entre la VSM, el IP y S/D y el número de células caliciformes del colon. PALABRAS CLAVE: Flujo mesentérico, Ecografía Doppler, Rata neonata, Isquemia - Reperfusión, ECN. / INTRODUCTION. Enterocolitis Necrotizing (NEC) is a digestive disease neonatal severe multifactorial and diverse etiology, characterized by inflammation and ischemia of the small intestine and colon progresses towards transmural necrosis and perforation. Prevalence is around one to three per every 1,000 newly births being greater in preterm infants weighing less than 1500 grams (g), is of very low birth. HYPOTHESIS. Mesenteric workflow changes by Doppler ultrasound color have correlation with intestinal macroscopic and microscopic lesions in an experimental model of ECN. MATERIALS AND METHODS. Studied two groups of 10 (control: 1 / ischemia: 2) and a group of 16 (reperfusion: 3) rats (Sprague-Dawley) 17 days with an average weight of 21 to 36 g boys. The variable ultrasound to compare were: maximum systolic velocity (MSV), average velocity (Va), diastolic flow (DF), peak reverse diastolic flow (PRDF), pulsatility index (PI), index of resistance (RI) and proportion or index systole/diastole (S/D). Histology to compare variables was: intestinal lesion (Wallace/Keenan scale/thin Chiu), average villous height (AVH), glandular hypertrophic and goblet cell mitosis. Ischemia-reperfusion model clamp is superior in its root mesenteric artery by 60 minutes (Group 2) and 24 hours for reperfusion (Group 3). Intra-abdominal ultrasound practical groups (1, 2 and 3) prior to slaughter. After the post mortem is identifying thin and thick bowel to take biopsies, they will be processed in hematoxilina-eosina for microscopic examination. The descriptive study was expressed in median (ranges). The significant results to the test of Kruskal - Wallis was using test U-Mann-Whiney comparison and correlation of Sperman ranges. Later in the case of finding a significant correlation was the study of nonlinear regression. We consider significant p<0,01. RESULTED. The variable sonogram and pathological anatomy that have a significant degree of Association (p<0,01) were: the MSV, the PI and S/D (Doppler ultrasound color) by pointing out a relationship with the scale of Wallace/Keenan, average Chiu in the small intestine, AVH, glandular hypertrophic of the large intestine and goblet cells of the large intestine. Group 3 compared groups 1 and 2, the VSM, IP and S/D found 5 significant associations (p<0,01) which relate to macroscopic scale of Wallace/Keenan, the microscopic scale of thin Chiu, the percentage of glandular hyperplasia of the large intestine AVH and number of goblet colon cells. CONCLUSIONS. Ischemia - reperfusion intestinal rat 17 days of life model achieves a similar to the of the Necrotizing enterocolitis described in the newborn human histopathological lesions. Systolic velocity (MSV) and vascular resistance rates (pulsatility [PI] - systole/diastole [S/D]) by Doppler ultrasound color in the superior mesenteric artery neonatal rat are increased in the NEC. There is a direct correlation between the MSV, the PI and S/D and the degree of intestinal lesion macroscopic (Wallace/Keenan) and microscopic (Chiu). There is an inverse correlation between the MSV, the PI and S/D and the average villous height (AVH). There is a direct correlation between the MSV, the PI and S/D and glandular hypertrophic in the colon. There is an inverse correlation between the MSV, the PI and S/D and the number of goblet colon cells. KEY WORD: mesenteric flow, ultrasound Doppler, Neonatal rat, Ischemia - Reperfusion, NEC.

Målet med projektet var att skapa en applikation för Ericsson AB R&amp;D som kan hjälpa till att analysera datatrafiken i deras nätverk (ECN). Det finns tre stycken accesspunkter till ECN som skyddas av brandväggar. Alla datauppkopplingar genom brandväggarna lagras dygnvis i loggar. Genom loggarna kan obehörig trafik upptäckas. Ett verktyg som analyserar brandväggsloggarna underlättar arbetet. Resultatet av mitt examensarbete är en applikation som är skriven i Perl. Programmeringsspråket Perl valdes för dess effektiva texthantering. Programmet exekveras genom terminalen (Solaris) / kommandoraden (Windows). De två viktigaste funktionerna är Searchlog och Check. Searchlog hanterar sökning av IP-adresser och Check kontrollerar att det inte finns några säkerhetsöverträdelser i brandväggsloggarna. Funktionerna har konstruerats så att största vikt är lagd på exekveringstiden och korrekt utdata. Slutsatsen av arbetet med brandväggsloggar är att det kräver testning för att få programmet att uppnå optimalt resultat. Perls reguljära uttryck var till stor hjälp i mitt arbete. De är bra vid behandling av stora mängder text. Minnesanvändningen kanske kan göras effektivare. Eftersom att exekveringstiden prioriterades kom det i andra hand. / The goal of this project was to construct an application that can analyze the traffic through the network (ECN) at Ericsson. There are three accesspoints to ECN protected by firewalls. The connections through the firewalls are logged daily. With the help from firewall logs unauthorized access can be found. A tool which analyzes the logs is therefore needed. The program is made in the computer language Perl. Perl was chosen because of its superior text handling capabilities. The application is executed through the terminal/command line. The two most important functions are Searchlog and Check. Searchlog handles the IP-searching and the Check function searches for unauthorized connections in the firewall logs. Execution time and data integrity were the main goals that were strived for. My conclusion is that working with firewall logs requires a lot of testing to achieve the best result. I realized that regular expressions is the easiest and most powerful tool to use when working with large amounts of text. Since the speed was prioritized and not memory usage there is room for memory improvement.

Today, data centers host a wide variety of applications which generate a mix of diverse internal data center traffic. In a data center environment 90% of the traffic flows, though they constitute only 10% of the data carried around, are short flows with sizes up to a maximum of 1MB. The rest 10% constitute long flows with sizes in the range of 1MB to 1GB. Throughput matters for the long flows whereas short flows are latency sensitive. This thesis studies various data center transport mechanisms aimed at either improving flow completion time for short flows or throughput for long flows. Thesis puts forth two data center transport mechanisms: (1) for improving flow completion time for short flows (2) for improving throughput for long flows. The first data center transport mechanism proposed in this thesis, FA-DCTCP (Flow Aware DCTCP), is based on Data Center Transmission Control Protocol (DCTCP). DCTCP is a Transmission Control Protocol (TCP) variant for data centers pioneered by Microsoft, which is being deployed widely in data centers today. DCTCP congestion control algorithm treats short flows and long flows equally. This thesis demonstrate that, treating them differently by reducing the congestion window for short flows at a lower rate compared to long flows, at the onset of congestion, 99th percentile of flow completion time for short flows could be improved by up to 32.5%, thereby reducing their tail latency by up to 32.5%. As per data center traffic measurement studies, data center internal traffic often exhibit predefined patterns with respect to the traffic flow mix. The second data center transport mechanism proposed in this thesis shows that, insights into the internal data center traffic composition could be leveraged to achieve better throughput for long flows. The mechanism for the same is implemented by adopting the Software Defined Networking paradigm, which offers the ability to dynamically adapt network configuration parameters based on network observations. The proposed solution achieves up to 22% improvement in long flow throughput, by dynamically adjusting network element’s QoS configurations, based on the observed traffic pattern.

The thesis focuses on the control of data flow in networks of Internet service providers. The problem of aggregation and related overload network elements are shown. Theoretical section describes the standardized methods for managing data flow. The parameters associated with managing data flow are described for devices selected devices. The thesis displays measurements depicting to which extent the ECN algorithm occurs in practice. In the thesis is theoretically described HTB program, which is complemented by a newly described algorithm. The new algorithm is implemented into the program and tested on a real network ISP.

No description available.