This document is a cover sheet for an assignment submitted by Abid Afsar, a student with number 2823134 studying Computing Science in the faculty of TNS at stage/year 1. The assignment is titled "TNS", is 20 pages long, and was submitted on December 23, 2011 to the lecturer Faheem Bukhatwa. The cover sheet includes a plagiarism disclaimer signed by Abid Afsar and notes that students must retain copies of their assignments.
ATM stands for Asynchronous Transfer Mode, which is a connection-oriented switching technique that uses time division multiplexing to transmit voice, video, and data communications in fixed-size cells. ATM networks encode data into 53-byte cells with a 5-byte header and 48-byte payload to allow for time division multiplexing over physical mediums. The ATM reference model has physical, ATM, and adaptation layers to convert data into cells, route cells through the network, and provide interfaces between ATM and other networks.
The OSI model is a conceptual model that characterizes and standardizes the communication functions of a telecommunication or computing system without regard to their underlying internal structure and technology. It defines seven layers of protocols for network communication: physical, data link, network, transport, session, presentation, and application. Each layer relies on the layer below it and provides services to the layer above it. The OSI model ensures compatibility between different systems and allows networks to work together.
This document contains questions about databases and networking concepts. It covers topics like database characteristics, roles, models, languages, and components. Regarding networks, it discusses transmission media, protocols, topologies, and applications like EDI and client/server computing. The questions are multiple choice designed to test understanding of fundamental database and networking concepts.
This document discusses different types of addressing modes used in instruction set architectures, including immediate addressing where the operand is present in the instruction, register or direct addressing where the address field directly contains the operand's address, indirect addressing where the address field refers to a word containing the operand's address, and displacement addressing which combines direct and indirect addressing by using a base register value and displacement value to calculate the operand's address. Displacement addressing provides more flexibility than direct addressing alone by allowing access to a larger address space.
The document discusses various topics related to computer networks including business applications, home applications, mobile users, and social issues. It then covers network hardware classifications including personal area networks, local area networks, metropolitan area networks, and wide area networks. The document also discusses network software topics such as protocol hierarchies, connection-oriented vs connectionless services, service primitives, and the relationship between services and protocols. It concludes with sections on reference models including the OSI and TCP/IP models.
Isolated Arabic Handwritten Character Recognition Using Linear CorrelationEditor IJCATR
Handwriting recognition systems have emerged and evolved significantly, especially in English language, but for the Arabic
language, such systems did not find that sufficient attention in comparison to other languages .Therefore, the aim of this paper to
highlight the Optical Character Recognition using linear correlation algorithm in two dimensions and then the programs can to identify
discrete Arabic letters application started manually, the program has been successfully applied.
The document provides information about the Bachelor of Computer Applications (BCA) program offered by Bharati Vidyapeeth Deemed University in Pune, India. The 3-year BCA degree program is divided into 6 semesters. To be eligible for admission, students must have passed the Higher Secondary Certificate (HSC) or equivalent exam with a minimum of 45% aggregate marks. The BCA examination consists of 4200 total marks divided across 3 parts over the 6 semesters. Coursework includes subjects like fundamentals of information technology, algorithms, C programming, database design, software engineering and more.
This document contains the questions and answers from a computer architecture and organization exam. It includes questions about the differences between computer architecture and organization, instruction formats, bus definitions, cache memory advantages, and virtual memory. The responses provide detailed explanations of concepts like locality of reference, thrashing, address mapping, cache hits and misses, and hierarchical memory systems. Justification is given for using a hierarchical approach to improve performance across different memory types. The differences between paging and segmentation in virtual memory are also distinguished.
ATM stands for Asynchronous Transfer Mode, which is a connection-oriented switching technique that uses time division multiplexing to transmit voice, video, and data communications in fixed-size cells. ATM networks encode data into 53-byte cells with a 5-byte header and 48-byte payload to allow for time division multiplexing over physical mediums. The ATM reference model has physical, ATM, and adaptation layers to convert data into cells, route cells through the network, and provide interfaces between ATM and other networks.
The OSI model is a conceptual model that characterizes and standardizes the communication functions of a telecommunication or computing system without regard to their underlying internal structure and technology. It defines seven layers of protocols for network communication: physical, data link, network, transport, session, presentation, and application. Each layer relies on the layer below it and provides services to the layer above it. The OSI model ensures compatibility between different systems and allows networks to work together.
This document contains questions about databases and networking concepts. It covers topics like database characteristics, roles, models, languages, and components. Regarding networks, it discusses transmission media, protocols, topologies, and applications like EDI and client/server computing. The questions are multiple choice designed to test understanding of fundamental database and networking concepts.
This document discusses different types of addressing modes used in instruction set architectures, including immediate addressing where the operand is present in the instruction, register or direct addressing where the address field directly contains the operand's address, indirect addressing where the address field refers to a word containing the operand's address, and displacement addressing which combines direct and indirect addressing by using a base register value and displacement value to calculate the operand's address. Displacement addressing provides more flexibility than direct addressing alone by allowing access to a larger address space.
The document discusses various topics related to computer networks including business applications, home applications, mobile users, and social issues. It then covers network hardware classifications including personal area networks, local area networks, metropolitan area networks, and wide area networks. The document also discusses network software topics such as protocol hierarchies, connection-oriented vs connectionless services, service primitives, and the relationship between services and protocols. It concludes with sections on reference models including the OSI and TCP/IP models.
Isolated Arabic Handwritten Character Recognition Using Linear CorrelationEditor IJCATR
Handwriting recognition systems have emerged and evolved significantly, especially in English language, but for the Arabic
language, such systems did not find that sufficient attention in comparison to other languages .Therefore, the aim of this paper to
highlight the Optical Character Recognition using linear correlation algorithm in two dimensions and then the programs can to identify
discrete Arabic letters application started manually, the program has been successfully applied.
The document provides information about the Bachelor of Computer Applications (BCA) program offered by Bharati Vidyapeeth Deemed University in Pune, India. The 3-year BCA degree program is divided into 6 semesters. To be eligible for admission, students must have passed the Higher Secondary Certificate (HSC) or equivalent exam with a minimum of 45% aggregate marks. The BCA examination consists of 4200 total marks divided across 3 parts over the 6 semesters. Coursework includes subjects like fundamentals of information technology, algorithms, C programming, database design, software engineering and more.
This document contains the questions and answers from a computer architecture and organization exam. It includes questions about the differences between computer architecture and organization, instruction formats, bus definitions, cache memory advantages, and virtual memory. The responses provide detailed explanations of concepts like locality of reference, thrashing, address mapping, cache hits and misses, and hierarchical memory systems. Justification is given for using a hierarchical approach to improve performance across different memory types. The differences between paging and segmentation in virtual memory are also distinguished.
This document outlines the syllabus for the second year of the BCA (Bachelor of Computer Applications) program for examinations from 2012-2014 at Jammu University. It includes details on 6 papers: Fundamentals of Discrete Mathematics, Data Structure using C/C++, Programming paradigm and C++, Circuits and Memory Organization, Database Management System, and Operating System & UNIX. For each paper, it lists the title, units of study, recommended textbooks, exam format, and % of changes compared to the previous syllabus.
The document provides information about the GPA and CGPA systems used at Universiti Sains Malaysia School of Computer Sciences. It outlines the grade point values assigned to different letter grades and lists courses that must be passed with a minimum grade of C. It also discusses the minor and elective packages available for computer science students, including popular minor options from other schools and elective courses within the school of computer sciences.
This document provides instructions for Assignment 2 of the course COIT20262 - Advanced Network Security. It consists of 4 questions related to firewall configuration, WiFi security, password schemes, and HTTPS certificate generation and analysis. Students must attempt all questions and submit their answers and any required files to the Moodle submission system. Collaboration is allowed for discussing approaches, but each student must develop their own answers and files. Copying of text or files from other sources is prohibited.
Here are the steps to launch Microsoft Visual Studio 2008 and create a project to edit the program P 2-1:
1. Launch Microsoft Visual Studio 2008.
2. Click "File" -> "New" -> "Project".
3. In the "New Project" dialog box, select "Visual C++" in the left pane and "Win32 Console Application" in the middle pane.
4. Click "OK".
5. In the "Win32 Application Wizard" dialog box, enter a name for the project (e.g. "AssemblyProgram") and click "OK".
6. This will create a new empty project in Visual Studio.
7. Right click on the
This document appears to be a project report template for a Master's student in Electronics and Telecommunication Engineering at SSBT's College of Engineering and Technology in Bambhori, Jalgaon, India. The summary includes:
1) The report is for a project titled "[Project Title]" submitted in partial fulfillment of a Master of Engineering degree in Electronics and Telecommunication (Digital Electronics).
2) Guidelines are provided for the report format including paper size, margins, fonts, chapter headings, references, and required sections.
3) The report must be a minimum of 40 pages and include an abstract, introduction, literature review, system design chapter(s), conclusions, and references.
4)
A NOVEL FEATURE SET FOR RECOGNITION OF SIMILAR SHAPED HANDWRITTEN HINDI CHARA...cscpconf
This document describes a study that uses machine learning algorithms to recognize similar shaped handwritten Hindi characters. It extracts 85 features from each character image based on geometry. Four machine learning algorithms (Bayesian Network, RBFN, MLP, C4.5 Decision Tree) are trained on datasets containing samples of a target character pair and evaluated based on precision, misclassification rate, and model build time. Feature selection techniques are also used to reduce the feature set dimensionality before classification. Experimental results show that different algorithms perform best depending on the feature set and number of samples used for training.
This document provides lecture notes on computer networks. It begins with an introduction to computer networks, defining them as interconnected autonomous computers that exchange information. It then discusses network models including the OSI reference model, which structures network communication across seven layers of abstraction. The document outlines the key concepts covered in each of the five units of an undergraduate course on computer networks.
Scheme g third semester (co,cm,cd,if, cw)anita bodke
This document outlines the teaching and examination scheme for the third semester of various diploma programs. It includes:
1. The subject Data Structure Using 'C' which has 4 hours of theory and 4 hours of practical classes per week. It will be examined through a theory paper worth 100 marks, a practical exam of 50 marks, and internal assessment of 25 marks.
2. Details of the Applied Mathematics subject including its objectives, learning structure, theory topics and contents across various engineering programs for the third semester.
3. Excerpts from documents providing more context on the Data Structure Using 'C' and Applied Mathematics subjects, including their objectives, importance, and learning outcomes for students.
The document discusses the teaching scheme and contents for the Operating System subject for the fifth semester of the Diploma in Computer Engineering course. It provides an overview of the subject, including its objectives, topics to be covered, teaching scheme with hours and marks allotted to each topic, and list of practical exercises. The subject aims to develop skills in understanding operating system concepts like processes, scheduling, memory management, file systems etc. It also provides an introduction to the UNIX operating system. The teaching scheme allocates 48 hours of theory classes and 18 hours of practical sessions.
Computer Organization and Assembly Languagefasihuddin90
This document provides an introduction to the CS-401 course on computer architecture and assembly language programming. It outlines the basic components of a computer, including the processor, memory, and buses that connect them, and describes how data is stored and addressed in memory at the basic level of binary digits.
This document provides an examination scheme for the M.Sc. (Computer Science) program from the previous 2012-13 session. It outlines the courses, papers, and distribution of marks for both semesters. Semester I includes 4 theory papers on topics like discrete mathematics, programming in C, computer organization & architecture, and windows & PC software. It also includes 2 practical exams and an internal project. Similarly, Semester II includes 4 theory papers covering data structures & algorithms, operating systems, computer networks, and Java & HTML, along with 2 practical exams and an external project. The document provides details on the distribution of marks for each course component and notes that projects will be internally assessed in Semester I and externally in Se
This document outlines the study and evaluation scheme for a Master of Technology degree in Computer Science/Information Technology at UPTU.
It provides the course codes, subjects, theory/tutorial/lab periods, and evaluation schemes for each semester. In semester 1, there are 4 core courses covering foundations of computer science, computer organization/architecture, operating systems, and data networks. Each has theory, tutorial, and lab components, with internal assessments worth 30-50 marks and end semester exams worth 100-150 marks.
Semester 2 covers 4 elective courses, with similar evaluation schemes. Semesters 3 and 4 include electives, a professional aspects course, seminar, and dissertation work. Evaluation includes internal and
This document describes the design of a three-layer knowledgebase for expert systems. The three layers are:
1) The logical/design layer, which processes input text to extract clauses, functional symbols, and predicate symbols.
2) The knowledge layer, which represents the extracted knowledge using techniques like first-order logic, frames, and description logic.
3) The storage layer, which stores the represented knowledge in an object-relational database for retrieval and use by the expert system.
The document provides details on each layer and discusses how the input text is processed in the logical layer before being represented and stored in the knowledge and storage layers, respectively.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This document proposes a model for classifying network troubleshooting issues according to the seven layers of the OSI model. It aims to standardize how network troubles are identified and expressed for more efficient network administration and troubleshooting. For each layer of the OSI model, the document categorizes the types of troubles that could occur on that layer. For example, on the Application layer troubles are divided into "Offline troubles" and "Online troubles", and on the Presentation layer they are divided into "Text troubles", "Audio troubles", and "Video-graphic troubles". The proposed model is intended to allow troubles to be identified at a more granular level for faster resolution of network issues.
This document provides an overview of key concepts from William Stallings' Computer Organization and Architecture textbook. It defines architecture as the attributes visible to a programmer, such as instruction set and data representation, while organization refers to how features are implemented internally, like control signals and memory technology. It notes that while instruction sets may be compatible across systems from the same manufacturer, the internal organization can differ between versions. The document also gives a high-level overview of the book's chapter topics and provides some recommended Internet resources for additional information on computer architecture topics.
Global TB remains a major health issue, with an estimated 9 million new cases and 1.5 million deaths in 2013. The African region accounts for a large proportion of HIV-positive TB cases and deaths. In 2013, an estimated 480,000 people developed MDR-TB globally. Egypt has made progress in reducing TB prevalence, incidence, and mortality rates since 1990, though case detection remains at 59%. Drug resistance surveys in Egypt found 3.4% of new cases and 32.1% of retreated cases had MDR-TB. New approaches are needed to improve treatment adherence and case detection.
SeRUPUT COLLECTION proudly presents a new product. They have developed a new line of goods that they are excited to share with customers. Details about the specific new product are not provided in the short document.
Este documento describe las características geográficas, climáticas y culturales de la región atlántica noroeste de Galicia, España. El clima es oceánico y templado, con abundantes precipitaciones. La cocina se centra en productos del mar ricos extraídos de las rías, y platos sencillos con menos de tres ingredientes. La cultura de la región se caracteriza por tradiciones, fiestas, autores como Alvaro Cunqueiro, e influencers actuales que promueven la identidad atlántica noroeste.
This document summarizes research analyzing the class relationship graphs of four Smalltalk systems. The researchers found that the degree distributions of the graphs follow power laws rather than a Poisson distribution, indicating the graphs have scale-free properties like many real-world complex networks. They conclude the object-oriented structures of the Smalltalk systems exhibit heavy-tailed distributions and regularities in their characteristic exponents. Further work is proposed to correlate graph properties with software quality and develop a growth theory to model software evolution.
This document outlines the syllabus for the second year of the BCA (Bachelor of Computer Applications) program for examinations from 2012-2014 at Jammu University. It includes details on 6 papers: Fundamentals of Discrete Mathematics, Data Structure using C/C++, Programming paradigm and C++, Circuits and Memory Organization, Database Management System, and Operating System & UNIX. For each paper, it lists the title, units of study, recommended textbooks, exam format, and % of changes compared to the previous syllabus.
The document provides information about the GPA and CGPA systems used at Universiti Sains Malaysia School of Computer Sciences. It outlines the grade point values assigned to different letter grades and lists courses that must be passed with a minimum grade of C. It also discusses the minor and elective packages available for computer science students, including popular minor options from other schools and elective courses within the school of computer sciences.
This document provides instructions for Assignment 2 of the course COIT20262 - Advanced Network Security. It consists of 4 questions related to firewall configuration, WiFi security, password schemes, and HTTPS certificate generation and analysis. Students must attempt all questions and submit their answers and any required files to the Moodle submission system. Collaboration is allowed for discussing approaches, but each student must develop their own answers and files. Copying of text or files from other sources is prohibited.
Here are the steps to launch Microsoft Visual Studio 2008 and create a project to edit the program P 2-1:
1. Launch Microsoft Visual Studio 2008.
2. Click "File" -> "New" -> "Project".
3. In the "New Project" dialog box, select "Visual C++" in the left pane and "Win32 Console Application" in the middle pane.
4. Click "OK".
5. In the "Win32 Application Wizard" dialog box, enter a name for the project (e.g. "AssemblyProgram") and click "OK".
6. This will create a new empty project in Visual Studio.
7. Right click on the
This document appears to be a project report template for a Master's student in Electronics and Telecommunication Engineering at SSBT's College of Engineering and Technology in Bambhori, Jalgaon, India. The summary includes:
1) The report is for a project titled "[Project Title]" submitted in partial fulfillment of a Master of Engineering degree in Electronics and Telecommunication (Digital Electronics).
2) Guidelines are provided for the report format including paper size, margins, fonts, chapter headings, references, and required sections.
3) The report must be a minimum of 40 pages and include an abstract, introduction, literature review, system design chapter(s), conclusions, and references.
4)
A NOVEL FEATURE SET FOR RECOGNITION OF SIMILAR SHAPED HANDWRITTEN HINDI CHARA...cscpconf
This document describes a study that uses machine learning algorithms to recognize similar shaped handwritten Hindi characters. It extracts 85 features from each character image based on geometry. Four machine learning algorithms (Bayesian Network, RBFN, MLP, C4.5 Decision Tree) are trained on datasets containing samples of a target character pair and evaluated based on precision, misclassification rate, and model build time. Feature selection techniques are also used to reduce the feature set dimensionality before classification. Experimental results show that different algorithms perform best depending on the feature set and number of samples used for training.
This document provides lecture notes on computer networks. It begins with an introduction to computer networks, defining them as interconnected autonomous computers that exchange information. It then discusses network models including the OSI reference model, which structures network communication across seven layers of abstraction. The document outlines the key concepts covered in each of the five units of an undergraduate course on computer networks.
Scheme g third semester (co,cm,cd,if, cw)anita bodke
This document outlines the teaching and examination scheme for the third semester of various diploma programs. It includes:
1. The subject Data Structure Using 'C' which has 4 hours of theory and 4 hours of practical classes per week. It will be examined through a theory paper worth 100 marks, a practical exam of 50 marks, and internal assessment of 25 marks.
2. Details of the Applied Mathematics subject including its objectives, learning structure, theory topics and contents across various engineering programs for the third semester.
3. Excerpts from documents providing more context on the Data Structure Using 'C' and Applied Mathematics subjects, including their objectives, importance, and learning outcomes for students.
The document discusses the teaching scheme and contents for the Operating System subject for the fifth semester of the Diploma in Computer Engineering course. It provides an overview of the subject, including its objectives, topics to be covered, teaching scheme with hours and marks allotted to each topic, and list of practical exercises. The subject aims to develop skills in understanding operating system concepts like processes, scheduling, memory management, file systems etc. It also provides an introduction to the UNIX operating system. The teaching scheme allocates 48 hours of theory classes and 18 hours of practical sessions.
Computer Organization and Assembly Languagefasihuddin90
This document provides an introduction to the CS-401 course on computer architecture and assembly language programming. It outlines the basic components of a computer, including the processor, memory, and buses that connect them, and describes how data is stored and addressed in memory at the basic level of binary digits.
This document provides an examination scheme for the M.Sc. (Computer Science) program from the previous 2012-13 session. It outlines the courses, papers, and distribution of marks for both semesters. Semester I includes 4 theory papers on topics like discrete mathematics, programming in C, computer organization & architecture, and windows & PC software. It also includes 2 practical exams and an internal project. Similarly, Semester II includes 4 theory papers covering data structures & algorithms, operating systems, computer networks, and Java & HTML, along with 2 practical exams and an external project. The document provides details on the distribution of marks for each course component and notes that projects will be internally assessed in Semester I and externally in Se
This document outlines the study and evaluation scheme for a Master of Technology degree in Computer Science/Information Technology at UPTU.
It provides the course codes, subjects, theory/tutorial/lab periods, and evaluation schemes for each semester. In semester 1, there are 4 core courses covering foundations of computer science, computer organization/architecture, operating systems, and data networks. Each has theory, tutorial, and lab components, with internal assessments worth 30-50 marks and end semester exams worth 100-150 marks.
Semester 2 covers 4 elective courses, with similar evaluation schemes. Semesters 3 and 4 include electives, a professional aspects course, seminar, and dissertation work. Evaluation includes internal and
This document describes the design of a three-layer knowledgebase for expert systems. The three layers are:
1) The logical/design layer, which processes input text to extract clauses, functional symbols, and predicate symbols.
2) The knowledge layer, which represents the extracted knowledge using techniques like first-order logic, frames, and description logic.
3) The storage layer, which stores the represented knowledge in an object-relational database for retrieval and use by the expert system.
The document provides details on each layer and discusses how the input text is processed in the logical layer before being represented and stored in the knowledge and storage layers, respectively.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This document proposes a model for classifying network troubleshooting issues according to the seven layers of the OSI model. It aims to standardize how network troubles are identified and expressed for more efficient network administration and troubleshooting. For each layer of the OSI model, the document categorizes the types of troubles that could occur on that layer. For example, on the Application layer troubles are divided into "Offline troubles" and "Online troubles", and on the Presentation layer they are divided into "Text troubles", "Audio troubles", and "Video-graphic troubles". The proposed model is intended to allow troubles to be identified at a more granular level for faster resolution of network issues.
This document provides an overview of key concepts from William Stallings' Computer Organization and Architecture textbook. It defines architecture as the attributes visible to a programmer, such as instruction set and data representation, while organization refers to how features are implemented internally, like control signals and memory technology. It notes that while instruction sets may be compatible across systems from the same manufacturer, the internal organization can differ between versions. The document also gives a high-level overview of the book's chapter topics and provides some recommended Internet resources for additional information on computer architecture topics.
Global TB remains a major health issue, with an estimated 9 million new cases and 1.5 million deaths in 2013. The African region accounts for a large proportion of HIV-positive TB cases and deaths. In 2013, an estimated 480,000 people developed MDR-TB globally. Egypt has made progress in reducing TB prevalence, incidence, and mortality rates since 1990, though case detection remains at 59%. Drug resistance surveys in Egypt found 3.4% of new cases and 32.1% of retreated cases had MDR-TB. New approaches are needed to improve treatment adherence and case detection.
SeRUPUT COLLECTION proudly presents a new product. They have developed a new line of goods that they are excited to share with customers. Details about the specific new product are not provided in the short document.
Este documento describe las características geográficas, climáticas y culturales de la región atlántica noroeste de Galicia, España. El clima es oceánico y templado, con abundantes precipitaciones. La cocina se centra en productos del mar ricos extraídos de las rías, y platos sencillos con menos de tres ingredientes. La cultura de la región se caracteriza por tradiciones, fiestas, autores como Alvaro Cunqueiro, e influencers actuales que promueven la identidad atlántica noroeste.
This document summarizes research analyzing the class relationship graphs of four Smalltalk systems. The researchers found that the degree distributions of the graphs follow power laws rather than a Poisson distribution, indicating the graphs have scale-free properties like many real-world complex networks. They conclude the object-oriented structures of the Smalltalk systems exhibit heavy-tailed distributions and regularities in their characteristic exponents. Further work is proposed to correlate graph properties with software quality and develop a growth theory to model software evolution.
Love can take many forms, from passionate romantic love to familial love. There are several types of love identified in ancient Greek - eros (passionate love), philia (friendship), agape (unconditional love), storge (familial love), and mania (obsessive love). Being in love is expressed through body language like making eye contact, smiling, leaning toward the other person, and constantly thinking about them. However, love can also be weakened by behaviors like misbehaving, ignoring, lying, breaking promises, avoiding contact, and doubting the other person. Different kinds of couples can also exist, such as romantic couples who plan things for each other, playful couples who joke around,
SeRUPUT COLLECTION proudly presents a new product. They have developed a new line of goods that they are excited to share with customers. Details about the specific new product are not provided in the short document.
Respiratory viruses 8 november 2014 wagdyWagdy Amin
This document discusses various epidemic viruses including SARS, avian influenza (H5N1), and influenza (H1N1, H3N2). It provides details on the origins, symptoms, treatment and global spread of these viruses. SARS originated in China in 2002 and had a mortality rate of around 10%. Avian influenza (H5N1) is endemic in birds and can be transmitted to humans, with a high mortality rate of 59%. Influenza viruses such as H1N1 have caused past pandemics and continue to mutate and spread globally.
Candle Heart is a faith-based nonprofit that runs a 3-6 month rehabilitation program for homeless individuals and families. It provides housing, food, job training, and Bible-based life skills education. 95% of participants successfully transition out of homelessness. However, Candle Heart relies heavily on government grants and lacks donations due to negative public perception of being a homeless shelter. The document recommends ways for Candle Heart to improve marketing and change public perception to focus on its success as a rehabilitation program in order to attract more donations.
This document is a report on Asynchronous Transfer Mode (ATM) switching that was written by Abid Afsar for an assignment. The 3-page report discusses several key topics in ATM switching including: ATM switch architecture types such as single bus, multiple bus, and self-routing [1]; functional components like input/output modules and switch fabrics [2]; and operations including routing, buffering, and connection admission control [3]. The report provides an overview of ATM switching technology.
The Pilgrims sailed from England to America on the Mayflower to escape religious persecution. They encountered hostility from some native tribes but received help from the Wampanoag Indians to survive their first harsh winter. The Pilgrims held a feast to thank God for helping them survive their first year, which became known as the first Thanksgiving.
This document presents an introduction to a thesis that compares the performance of routing protocols in wireless sensor networks. It provides background on wireless sensor networks and discusses routing as an important issue. The introduction defines the problem, motivation, research questions, methodology, aims, assumptions, contributions, and organization of the thesis. It includes figures to illustrate typical wireless sensor network components, different network topologies, deployment densities, and a bar chart on simulation pause time.
This document discusses the benefits of implementing a live shopping system for a department store. Live shopping allows customers to view and purchase products online in real-time without needing to be physically present in the store. The presentation outlines advantages like lower overhead costs, improved customer profiling and loyalty, and an expanded customer reach. It also details how the proposed system would integrate an online shopping module with the department store's existing infrastructure and private gateway. Key technologies like JSP, JavaScript, HTML, MySQL, JDBC, and Tomcat are presented as the tools that would power the front-end and back-end of the live shopping platform. The overall expected outcome is the development of a functional live shopping system for the department store.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive functioning. Exercise causes chemical changes in the brain that may help protect against mental illness and improve symptoms.
The ocean covers over 70% of Earth's surface and contains over 97% of the planet's water. However, less than 5% of the ocean has been explored by humans to date. As technology advances, scientists are discovering new species, ecosystems, and geological features in the deep ocean that were previously unknown. In summary, the ocean remains a vast, mysterious domain that holds many secrets still to be uncovered through continued exploration and research.
The document is a project proposal for developing a live shopping system. It outlines the goals of creating an online shopping application that provides features like product searching, wish lists, notifications, and tracking of deliveries. The proposal discusses the motivation to address problems with existing online shopping and the objectives to develop a reliable and functional virtual shopping experience. It also provides details on the technologies to be used like Java, MySQL, and Tomcat as well as a proposed project schedule.
This document provides an overview of Asynchronous Transfer Mode (ATM) networking. It begins by stating the objectives of explaining ATM and then provides background on ATM, noting that it transfers information in small, fixed-size cells. It describes the benefits of ATM, including dynamic bandwidth allocation and support for multimedia traffic. It then explains the basic components of an ATM network, including switches and endpoints, and describes the ATM cell format and header fields. Finally, it introduces the concept of virtual connections in ATM networks.
Question 1The OSI model has seven layers where each layer pe.docxssuser774ad41
Question 1
The OSI model has seven layers where each layer performs various functions that are integrated to ensure that the network performs efficiently. The layers are arranged as follows from the bottom to the top layer:
a) The physical layer:
This is the first layer of the model and it has several functions. These are:
i. Bit synchronization:
The physical layer is very crucial in terms of timing and synchronizing the period and the amount of bits that are transferred between the sender and the recipient of a message. It uses a clock to ensure accurate and reliable synchronization.
ii. Bit rate control:
The physical layer also controls the bandwidth in a network by determining the number of bits that are transferred over the network channel within the specified time which is seconds in most cases.
iii. Physical topologies:
The physical layer also determines the design which is used to connect all the devices that make up the network. These include routers, switches, hubs and other equipment used in a network.
iv. Transmission mode:
The connection of devices in the physical layer determines how data between the communicating devices flows. There are various transmission modes which are supported by the physical layer. These are simplex, half-duplex and full-duplex. In simplex, data flows in only one direction. In half-duplex data can flow in both directions but not simultaneously. In the full-duplex transmission mode, data flows in both directions at the same time.
b) Data Link Layer:
This is the second layer of the OSI model. Some of its functions include:
i. Framing:
Data that is being transmitted is segmented into pieces known as frames to make the transmission process easier. The Data link layer facilitates the framing process to ensure that the receiver acquires the accurate and relevant information within the shortest possible time.
ii. Physical addressing:
The frames require adequate data regarding the sender and the recipient to ensure that a message does not fail to reach the intended recipient. The Data Link Layer achieves this by adding a MAC address to the header section of each of the frames that are being transmitted.
iii. Error control:
The use of frames in the DLL enables the network layer to detect when frames do not reach the intended recipient. In return, the DLL is able to retransmit the lost or damaged frames using the details in the headers.
iv. Flow control:
The DLL ensures that the flow of data between the sender and the recipient is constant. This techniques ensures the stability of the communication channel that is established when transmitting data.
v. Access control:
The assigning of MAC addresses to all the computers in a network enables the Data Link Layer to determine the machines with access to certain resources.
c) Network layer:
The functions of the third OSI model layer are:
i. Routing:
The network layer assesses the different routes that a frame can use to reach its recipient and it chooses the best rou ...
The document discusses the history and development of ATM networks. It explains that ATM networks emerged from standardization activities around Integrated Services Digital Networks (ISDN) in the 1970s. This was driven by the trend toward an all-digital telephone network and the need to support digital connectivity for end users as well as non-voice applications like data and video. The document then provides details on the ATM cell header format and its various fields that are used to identify connections and support different types of traffic and services.
This document provides information about data communication networks for 4th year B.Tech ECE students at Ashoka Institute of Technology & Management in Varanasi, India. It covers topics like the criteria for effective networks, the OSI model layers grouped by function, how headers and trailers are added and removed in layers, the features provided by layering, why protocols are needed, the interfaces provided by protocols, different physical media, signals, wavelength, modulation, duplex types, CODECs, spread spectrum techniques, encoding, the differences between NRZ-L and NRZ-I, the responsibilities of the data link layer, ways to address framing, peer-to-peer vs. primary-secondary relationships, error types and detection
The document discusses the Open Systems Interconnection (OSI) model, which defines seven layers of network architecture - physical, data link, network, transport, session, presentation, and application. It describes the key functions of each layer, such as the physical layer dealing with physical connections and bits, the data link layer handling framing and addressing, and the application layer providing services to end users. The purpose of the OSI model is to facilitate communication between different computer systems by dividing the network communication process into standardized layers.
This document contains 16 important questions covering various topics related to computer networks across 5 units. The questions cover topics such as the ISO-OSI model, data encoding schemes, error detection and correction mechanisms, network layer protocols, transport layer protocols, network security, application layer protocols, and web technologies. Key topics include data link layer functions, error detection methods, flow control, network layer routing protocols, transport layer protocols TCP and UDP, network security concepts, and application layer protocols like HTTP, FTP, and DNS.
Asynchronous Transfer Mode (ATM) is a cell-switching and multiplexing technology that uses fixed-length packets called cells to carry different types of traffic like voice, video, and data. ATM works by segmenting data into these fixed-size cells which are then transmitted through virtual connections set up across an ATM network and reassembled at their destination. It provides benefits like high performance, Quality of Service guarantees, and the ability to handle different traffic types.
This document provides an overview of the syllabus for a Computer Networks course. It includes:
- An outline of the course units which cover data communication components, the OSI model, TCP/IP model, and each layer of the OSI model from layers 2 through 7.
- Evaluation criteria which includes continuous internal evaluation, semester end examination, and mandatory minimum marks.
- Suggested reading materials including textbooks and publications.
- An overview of the Computer Networks lab covering various experiments involving networking tools, protocols, programming, and simulation.
This includes description about what is ATM, its definition, layers, applications, working procedure, format type, available data bit rates, necessity of ATM, benefits & difference between Internet & ATM Network.
This document discusses layered network models, specifically the OSI model and TCP/IP model. It provides an overview of each layer in both models and their functions. The key points are:
- The OSI model defines 7 layers that break communication into smaller parts to simplify the process and allow different hardware/software to work together.
- The TCP/IP model has 4 layers - application, transport, internet, and network access. It is used widely on the internet.
- Each layer adds header information to data as it moves down the stack. This encapsulation allows communication between layers and across networks.
The document is an assignment for a Computer Networks course consisting of 10 multiple choice questions worth 6 marks each, for a total of 60 marks. The first question asks students to write about the ISO OSI model, describing its layered architecture and purpose in facilitating communication between different systems. Subsequent questions ask students to describe ISDN architecture and usage, discuss various LAN protocols including CSMA/CD and IEEE 802 standards, explain framing in the data link layer, summarize the TCP/IP protocol suite, and discuss various transmission and switching techniques.
This document provides an overview of the CS303: Computer Networks course, including the evaluation scheme, topics to be covered, and introductory information on data communications, networks, protocols, layered tasks, the OSI model, TCP/IP protocol suite, and addressing in networks. The key topics include data communication components and data flow, physical network structures and categories, elements of communication protocols, layered approaches to tasks, the seven layers of the OSI model and functions of each layer, comparison of OSI and TCP/IP models, and different types of addresses used including physical, logical, port, and specific addresses.
Dear students get fully solved assignments
Send your semester & Specialization name to our mail id :
help.mbaassignments@gmail.com
or
call us at : 08263069601
Dear students get fully solved assignments
Send your semester & Specialization name to our mail id :
“ help.mbaassignments@gmail.com ”
or
Call us at : 08263069601
(Prefer mailing. Call in emergency )
Dear students get fully solved assignments
Send your semester & Specialization name to our mail id :
help.mbaassignments@gmail.com
or
call us at : 08263069601
This document contains questions and answers related to communication networks. It covers topics like data communication, network criteria, characteristics of data communication systems, advantages of distributed processing, need for protocols and standards, topologies, active and passive hubs, peer-to-peer vs primary-secondary relationships, OSI layers and their functions, framing, error detection methods like parity checks, checksums, and cyclic redundancy checks, flow control methods like stop-and-wait and sliding windows, error correction, HDLC frames and fields, LAN architectures like Ethernet, token bus, token ring, and FDDI.
Switching and multicast schemes in asynchronous transfer mode networksEditor Jacotech
This document summarizes various switching and multicast schemes used in asynchronous transfer mode (ATM) networks. It discusses shared memory ATM switching architectures and different approaches for supporting multicast traffic in shared memory switches including replication-at-receiving, replication-at-sending, multiple write multiple read, and single write single read schemes. It also covers requirements for ATM multicast and compares these schemes in terms of advantages and disadvantages related to memory usage and switching performance.
1. The document discusses network integration and communication architectures, describing layered network models like OSI and TCP/IP.
2. It explains key aspects of each layer in the OSI model and their functions in facilitating communication across a network.
3. The physical and data link layers deal with physical transmission and frame handling, while higher layers include network, transport, and application layers.
Similar to Mscc Tns Assignment Ii Student Number 2823134 Abid Afsar (20)
Mscc Tns Assignment Ii Student Number 2823134 Abid Afsar
1. Abid Afsar TNS Assignment II Student Number: 2823134
Assignment Cover Sheet
Student name: Abid Afsar
Student number: 2823134
Faculty: Computing Science
Course: TNS Stage/year: 1
Subject:
Study Mode: Full time Yes Part-time
Lecturer Name: Faheem Bukhatwa
Assignment Title: TNS
No. of pages: 20
Disk included? Yes No No
Additional (ie. number of pieces submitted, size of assignment, A2,
Information: A3 etc)
1
2. Abid Afsar TNS Assignment II Student Number: 2823134
Date due: 23/12/2011
Date submitted: 23/12/2011
Plagiarism disclaimer:
I understand that plagiarism is a serious offence and have read and understood
the college policy on plagiarism. I also understand that I may receive a mark of
zero if I have not identified and properly attributed sources which have been used,
referred to, or have in any way influenced the preparation of this assignment, or if I
have knowingly allowed others to plagiarise my work in this way.
I hereby certify that this assignment is my own work, based on my personal study
and/or research, and that I have acknowledged all material and sources used in its
preparation. I also certify that the assignment has not previously been submitted
for assessment and that I have not copied in part or whole or otherwise plagiarised
the work of anyone else, including other students.
Signed: _______ ______________ Date:
___23/12/2011___________________
Please note: Students MUST retain a hard / soft copy of ALL assignments as well as a receipt issued and
signed by a member of Faculty as proof of submission.
(1) Compare the ATM protocol’s architecture and associated
layers, to those of the ISO-OSI reference model. Your answer or
diagram should show the layers in each protocol stack.
Answer:
2
3. Abid Afsar TNS Assignment II Student Number: 2823134
• International organization for standardization (ISO) also referred
as Open system interconnection (OSI) reference model has the
following seven layers,
i. Application layer
ii. Presentation layer
iii. Session layer
iv. Transport layer
v. Network layer
vi. Data link layer
vii. Physical layer
In comparison to OSI reference model, asynchronous transfer mode
(ATM) has the following three layers
i. ATM Adaptation layer
ii. ATM layer
iii. Physical layer
• The OSI model is used for the transmission over unreliable
medium, while ATM model works with reliable transmission
medium, and it also accommodate a mechanism for error
detection and correction.
• In term of reliability ATM is currently the most reliable mode
of transmission in comparison to OSI model.
3
4. Abid Afsar TNS Assignment II Student Number: 2823134
• ATM model corresponds to functionality physical and portion
data layer of OSI model.
• Diagrammatically the concept is represented as
Figure 1: Comparison Diagram of ATM and OSI Architecture
4
5. Abid Afsar TNS Assignment II Student Number: 2823134
• OSI lowest layers are related to ATM, and diagrammatically it is
represented as,
Figure 2: Relation of OSI and ATM
(2) Show with the help of a diagram the flow of cells in a real
Communication from end to end, up and down the layers in the
ATM Model. Show two intermediate switches in the diagram.
5
6. Abid Afsar TNS Assignment II Student Number: 2823134
Answer:
• In term of sending user information, ATM protocol architecture
is similar to TCP/IP protocol suit. ATM works same like
TCP/IP to forward user information form one machine to
another in the form of packets.
• In regards to routing or switching and control is completely
different because it fully connection- oriented which it establish
in form of virtual connection
• First a unique virtual connection is established which have their
VCI number
• Next communication begin and signalling standard agreement
take place and then data transmission start from one user
machine to another and exactly an original data order
• Finally, on completion of transmission connection is terminated
• ATM network mange data in specific order to manage the
quality of services in a most sophisticated manner
• On higher level it uses user plan and control plan for data
• Diagrammatically the concept is visualised as,
6
7. Abid Afsar TNS Assignment II Student Number: 2823134
Figure 3: End- to-End Communication an ATM network
(3) Describe in details the ATM Cell structure.
Answer:
• An ATM use a fixed cell also called packet which is
composed of 5 bytes of header and 48 bytes of payload. All
data in ATM network is switched and multiplexed in the form
of ATM cell.
7
8. Abid Afsar TNS Assignment II Student Number: 2823134
• In diagrammatic form it is represented as
ATM Cell
Figure 4: ATM Cell
• ATM cell header can have the following two header format
that is UNI (User to Network Interface) and NNI (Network-
to-Network Interface). The UNI is interface is between
network device and end user while NNI is between network
to network device or between the two back bone networks
8
9. Abid Afsar TNS Assignment II Student Number: 2823134
• Diagrammatically the concept of UNI and NNI is illustrated
as,
Figure 5: UNI and NNI interface format
• The above diagram can be explained as, in ATM cell header
fields the first one is GFC( generic flow control) it provides
local function, the second one is VPI(virtual path identifier)
it is a unique identification number for every virtual path,
third one is VCI (virtual channel number) it is a unique
identification number of every virtual circuit, fourth one is
Payload type identify that weather it contain user data or
control data, fifth one is CLP(congestion lost priority) it
identify that if a cell shows congestion it should be
9
10. Abid Afsar TNS Assignment II Student Number: 2823134
discarded or it show the status of congestion in the network
and sixth one is HEC(header error control) it provided
information in relation to any error encountered
• Multiplexing is also in important feature of ATM cell, it
multiplex different forms of data such voice, video and text.
Multiplexing improve overall efficiency and also improve
the performance of overall resources, diagrammatically it is
illustrated as
Figure 6: ATM Cell Multiplexing
(4) Describe the address fields used for ATM addressing. Use a
diagram to show the fields.
Answer:
10
11. Abid Afsar TNS Assignment II Student Number: 2823134
• ATM address use virtual circuit and it is 20 bytes in length
and the ATM has three distinct formats, in general term it is
represented as
Figure 7: ATM address Format
• The parts of an ATM address can be defined as, the first part
is the ATM switch identifier it composed of 13 bytes, and
identifies the switch position in network. The main three
addressing scheme viewing location of switch differently.
The second one is adapter MAC address hold 6 bytes. It
shows the particular adapter type in the ATM network and the
MAC address operation is similar like in Ethernet or token
ring. The third one is selector (SE) hold a space of 1 byte, and
it chooses a logical connection end point on physical ATM
adapter.
• The three addressing schemes use in ATM networks are
i. Data Country/region Code (DCC)
ii. International Code Designator (ICD)
11
12. Abid Afsar TNS Assignment II Student Number: 2823134
iii. E.164
The three different format of ATM address is
diagrammatically illustrated as
Figure 9: ATM Distinct Address Format
(5) Describe the structure of the ATM Adaptation layer AAL5 and
the services provided by each.
Answer:
• The AAL layer provide interface to the upper layer of the
ATM reference model
12
13. Abid Afsar TNS Assignment II Student Number: 2823134
• It further sub divide into two sub layers that is segmentation
and reassembling, and convergence
• The basic duty of ALL layer is the format conversion
• The ALL received 48 bytes payload from higher level layer
and a header of 5 bytes from ATM layer
• ALL have four different types that are AAL 1, ALL 2/3, ALL
4 and AAL 5.
• These different types of ALL’s can also be distinguished by
connection oriented or connectionless mechanism. The ALL
1, 2,5 are pulley connection oriented while ALL ¾ is partly
connection oriented and AAL ¾ is partly connectionless as
well.
• Diagrammatically it is represented as
13
14. Abid Afsar TNS Assignment II Student Number: 2823134
(6) What are Partial Packet Discard (PPD) and Early Packet
Discard (EPD)?
Answer: these are the ATM cell discard techniques and segments
large size packets into a series of bursts at ATM and ALL 5 cells.
This phenomenon is very useful at ATM over IP (AIP) and ATM
over LAN emulation (LANE) networks. These techniques closely
work with traffic policy and also look on to QoS as well. When the
cells of a large packet are dropped due to some reason and some of
the fragmented packets are also discard and will be send for
transmission. The discarding or dropping of fragmented packets are
call partial packet discard (PED). And when cells are fragmented
portion of a large packet, and are known in advance that the buffer
space is not sufficient to accommodate the entire packet, and then
there is no need to send some of its cells. It is better to discard the
entire packet and will be retransmitted this whole phenomena is
called early packet discard (EPD)
(7) Discuss in details four traffic control mechanisms used in the
ATM Model.
Answer: the ATM network should always be capable to recover
from any sort of potential errors, weather a human or machine error
such as intermittent or accidental and so on. The following control
mechanism are widely used in ATM traffic management arena
14
15. Abid Afsar TNS Assignment II Student Number: 2823134
1. Network Recourse Management: This is always a priority of
network management to achieve good quality and efficiency,
and meet the user quality of service requirements. There is no
perfect standard for network resource is available until today.
The core problem is the statistical behaviour of the ATM
networks because several cells were entered into the buffer from
different sources and also due multiplexing as well.
2. Connection Admission Control: it is the initial call setup
procedure, and to establish a virtual channel or path that is
acceptable to the network. It will make sure that the new
connection will not devalue the other connection already in
place and the quality of other channel is not affected.
3. Usage Parameter Control and Network parameter Control
(UPC/NPC): These two techniques doing different function at
network interface. The UPC is functioning on user network
interface while NPC functioning on network node interface. the
main purpose of UPC and NPC is to secure the network
resources from intentional and malicious attack. It will also
check the validity of VPI/VCI entries, monitor traffic volume for
the agreed traffic parameter and standards and guarantee that all
traffic obeying the specified criteria, and check the accepted
traffic volume on each access link.
15
16. Abid Afsar TNS Assignment II Student Number: 2823134
4. Priority Control: An ATM cell have the priority cell loss bit in
the header. And the information is classed according to their
priority and at least an ATM cell has two distinguished classes.
5. Traffic Shaping: It is a form of alerts given at the time when
there is a speedy traffic on an access link, these alerts are given
to slow their peak cell rate, limit the cell delay by appropriately
organising the cells in time.
6. Congestion Control: is a state of a network in which the traffic
overload or overflow on the network, everything jammed , and
no new network connection can be established, the
unguaranteed quality of service network is not able to add or
remove network connection. These problem can be solved by
using the above mechanism such as connection admission, and
UPC and NPC.
(8) Explain in detail how IP over ATM takes place. Your
explanation must discuss: connecting IP to an ATM, addresses and
the transfer of IP data grams.
Answer: ATM network is connection oriented network and it
widely support network protocols such as IP, Framerelay, and
IPv6, IPX, Decnet and so on. An ATM use three types of
connection which are permanent virtual circuit (PVC) and Soft
PVC, and short virtual circuit (SVC). The ATM network is divided
16
17. Abid Afsar TNS Assignment II Student Number: 2823134
into logical networks and each logical network has own separate IP
subnet also called logical subnet (LIS). Every system in the LIS has
share the same IP prefix and net mask. In LIS end system
communicant with each other through ATM end-to-end
connection. And in a different LIS’s the communication is take
place through router.
(9) Describe the link state routing algorithm and list its advantages
over distance vector routing algorithm.
Answer:
Link state is a routing protocol such as OSPF and IS-IS used in
packet switch networking in computer communication. The main
concept of the link state routing protocol is that every network node
has to take routing information of the connected neighbours in the
form of a table. Every network node calculates best to the other
concerned destination. The calculated best path is then place in
routing table.
Advantages:
1. Link state algorithm converge fast than distance vector protocol
2. It use multicast to share the network information
3. It support classless routing
4. Link state operate better at large enterprise network
17
18. Abid Afsar TNS Assignment II Student Number: 2823134
5. It has small routing table
6. It is capable of scalability
7. It has a low network overhead
8. It has no node limits
9. It use cost for shortest path findings
(10) Compare memory requirement imposed on the receiver node
by selective reject protocol and the go-back-N protocol. Give
examples to support your answers.
Answer:
Go-Back-N protocol manage the transmission time involved at
receiver end, and the transmission time of acknowledgment to come
back at sender end, and are carefully checked for efficiency purpose
and the technique is called pipelining. The sender is obliged to keep
track of frames and their concerned acknowledgment, and also have
to look timeout interval as well. As a result of tracking of each record
the memory requirement for sender is increased. On the other hand
the receiver only receives the frame or acknowledgment which the
receiver need. In situation where frame lost or duplication occurs in
frames or acknowledgments, the receiver discards whole frame, and
call for resend. In memory perspective the receiver only need
memory, when the frame is in right order with no error, lost and
duplication.
18
19. Abid Afsar TNS Assignment II Student Number: 2823134
For example: we want to send frames of window size 9, can be shown
in the following figure
Sender End 0 1 2 3 4 5 6 7 8
Ack 0 Ack 1
Receiver End 0 1 2 3 4 5 6 7 8
discard discard discard discard discard discard
Error
Retransmission of the same frames
Sender End 2 3 4 5 6 7 8
Ack 2 Ack 3 Ack 4 Ack 5 Ack 6
Receiver End 2 3 4 5 6 7 8
In the above figure error occur in frame 2 and all the subsequent
frames were also discarded. The sender was not aware of the problem,
and again sends the same copies of the frame because of the timeout
interval expiry. The limitation of go-back-n protocol is the sender
unawareness of the problem, and this makes it inefficient. And
negatively affect the channel usage, memory at sender side, and
bandwidth.
19
20. Abid Afsar TNS Assignment II Student Number: 2823134
In contrast selective reject protocol when the problem occur during
delivery of the frames, only particular frames were send back again
by the sender. On the receiver end all frames are not discarded and
only damage frame is acknowledged. In selective reject protocol
receiver side buffer size is increased because of keeping every correct
frame send by the sender. In this technique both sender and receiver
vigilantly watch their time counter, and the receiver have knowledge
that which frame has a problem and need to be re-acknowledge. It
uses NAK (negative acknowledgment) for lost or damaged bit
retransmission.
For example: we want to send frames of window size 9, using
selective reject protocol is shown in the following figure
Sender End 0 1 2 3 4 5 6 7 8
Ack 0 Ack 1
NAk 2
Ack 1 Ack 2 Ack 3 Ack 4
Receiver End 0 1 2 3 4 5 6 7 8
buffered buffered buffered buffered buffere buffered
Error
d
20
21. Abid Afsar TNS Assignment II Student Number: 2823134
Selective reject protocol improves the channel usage time and
bandwidth, and also has a positive effect on the overall efficiency of
transmission between sender and receiver.
Bibliography
21
22. Abid Afsar TNS Assignment II Student Number: 2823134
[1]. Tanenbaum, Andrew S. Computer Networks. Upper Saddle
River, NJ: Prentice Hall PTR, 1996. Print.
[2]. Händel, Rainer, Manfred N. Huber, Stefan Schröder, and Rainer
Händel. ATM Networks: Concepts, Protocols, Applications.
Wokingham, England: Addison-Wesley Pub., 1994. Print.v
[3]. ATM Addresses." Microsoft TechNet: Resources for IT
Professionals. Web: 23 Dec. 2011
<http://technet.microsoft.com/en-us/library/cc976977.aspx>.
[4]. Clark, Martin P. ATM Networks: Principles and Use. Chichester,
England: Wiley/Teubner, 1996. Print.
22