sir-cenon-2nd-sem.docx

INTECH 3111 Integrative Programming and Technologies 1 Intersystem Communication Inter – between, among. System - a group of interacting or interrelated entities that form a unified whole or our computer system. Communication - the imparting or exchanging of information or news. Intersystem Commun...

INTECH 3111 Integrative Programming and Technologies 1 Intersystem Communication Inter – between, among. System - a group of interacting or interrelated entities that form a unified whole or our computer system. Communication - the imparting or exchanging of information or news. Intersystem Communication the transfer of data between systems It is the ability of two or more computer systems to share input, output, and storage devices, and to send messages to each other by means of shared input and output channels or by channels that directly connect central processors. Intersystem communication is used in distributed computing. Middleware Integration middleware is a 3rd-party tool that allows you to connect two or more applications. Integration middleware represents software systems that offer runtime services for communications, integration application execution, monitoring and operations. Classified based on domains Cloud Integration: Integrates with and also between the cloud services, cloud-based applications (SaaS), private clouds, trade hubs and other typical cloud resources through Web services and standard B2B communication strategies (FTP, AS2, etc.) B2B Integration: Integrates customer, provider and various alternative partner interfaces with various data resources and company-managed applications Application Integration (A2A): Integrates various company-managed applications together, including cloud-based and remote systems Data Integration: Integrates business data resources, such as databases and files, over business and operational intelligence systems Middleware is often described as plumbing because it links both sides of an application and also transfers data between them. Some standard middleware categories include: Enterprise service buses (ESBs) Transaction processing (TP) monitors Distributed computing environment (DCE) Remote procedure call (RPC) systems Object request brokers (ORBs) Message passing Database access systems Why do organizations use Middleware? It lets you avoid point-to-point integrations Point-to-point (P2P) integrations, or the use of custom code to stitch together applications, is fraught with issues: Your developers have to invest a significant amount of time on building to applications’ APIs and in maintaining those connections—taking them away from other business-critical tasks they’re uniquely suited to perform. You’re forced to over rely on select developers; only they know where the code lives and how to troubleshoot and improve integrations. As a result, when they leave your company, the long-term performance of your integrations will likely be affected. You’re unable to implement new integrations fast enough; your developers may be tasked with higher priority projects or find that the scope of build is extensive. It often exceeds native integrations’ capabilities Native integrations, or integrations that the applications themselves make available, are also far from perfect. It offers enterprise-grade security and governance Middleware tools, particularly iPaaS solutions, have a track record of protecting sensitive, business-critical data effectively. Web Services are a method of communication between twoelectronic devices over the World Wide Web (WWW) network. They allow applications to communicate with each other and exchange data in a standardized format, such as XML or JSON. WS and Middleware Web Services provide a standardized way for applications to communicate over the WWW network, while Middleware acts as an intermediary to facilitate communication and exchange of data between different applications and systems. Web Services REST (Representational State Transfer) - a type of web service that uses HTTP requests to GET, PUT, POST and DELETE data. It is a lightweight, flexible and fast alternative to SOAP (Simple Object Access Protocol) services SOAP - a protocol for exchanging structured information in the implementation of web services. It is an XML-based messaging protocol for exchanging information among computers XML-RPC - a remote procedure call (RPC) protocol encoded in XML. Itis used to make remote calls from one application to another overthe web JSON-RPC - a remote procedure call (RPC) protocol encoded in JSON. It is a light-weight alternative to XML-RPC and is often used in AJAX-based web applications Network Programming Network programming is the act of using computer code to write programs or processes that can communicate with other programs or processes across a network Programmers use various programming languages, code libraries, and protocols to do the work Common Internet protocols TCP/IP HTTP FTP OSI Model The OSI Model (Open Systems Interconnection) is a conceptual framework used to describe the functions of a networking system. OSI model characterizes computing functions into a universal set of rules and requirements in order to support interoperability between different products and software. 7 Layers Application Layer At this layer, both the end user and the application layer interact directly with the software application. This layer sees network services provided to end-user applications such as a web browser or Office 365 Presentation Layer The presentation layer formats or translates data for the application layer based on the syntax or semantics that the application accepts. at times also called the syntax layer. This layer can also handle the encryption and decryption required by the application layer. Session Layer The session layer controls the conversations between different computers A session or connection between machines is set up, managed, and determined at layer 5. Session layer services also include authentication and reconnections. Transport Layer The transport layer manages the delivery and error checking of data packets. It regulates the size, sequencing, and ultimately the transfer of data between systems and hosts. One of the most common examples of the transport layer is TCP or the Transmission Control Protocol. Network Layer The network layer is responsible for receiving frames from the data link layer, and delivering them to their intended destinations among based on the addresses contained inside the frame Data link Layer At the data link layer, directly connected nodes are used to perform node-to-node data transfer where data is packaged into frames. The data link layer also corrects errors that may have occurred at the physical layer. The first, media access control (MAC), provides flow control and multiplexing for device transmissions over a network the logical link control (LLC), provides flow and error control over the physical medium as well as identifies line protocols. Physical Layer The lowest layer of the OSI Model is concerned with electrically or optically transmitting raw unstructured data bits across the network from the physical layer of the sending device to the physical layer of the receiving device. It can include specifications such as voltages, pin layout, cabling, and radio frequencies. At the physical layer, one might find “physical” resources such as network hubs, cabling, repeaters, network adapters or modems. TCP/IP or Transmission Control Protocol/Internet Protocol - is a suite of communication protocols used to interconnect network devices on the internet Socket Programming A socket is one endpoint of a two way communication link between two programs running on the network. The socket mechanism provides a means of inter-process communication (IPC) by establishing named contact points between which the communication take place. The socket provides bidirectional FIFO Communication facility over the network. A socket connecting to the network is created at each end of the communication. Each socket has a specific address. This address is composed of an IP address and a port number. Socket are generally employed in client server applications The server creates a socket, attaches it to a network port addresses then waits for the client to contact it. The client creates a socket and then attempts to connect to the server socket. When the connection is established, transfer of data takes place 2 Types of socket Datagram Socket Stream Socket Datagram Socket This is a type of network which has connection less point for sending and receiving packets. It is similar to mailbox. The letters (data) posted into the box are collected and delivered (transmitted) to a letterbox (receiving socket). Connectionless sockets User Datagram Protocol (UDP). Each packet sent or received on a datagram socket is individually addressed and routed. Order and reliability are not guaranteed with datagram sockets, so multiple packets sent from one machine or process to another may arrive in any order or might not arrive at all. Stream Pocket is type of interprocess communications socket or network socket which provides a connection-oriented, sequenced, and unique flow of data without record boundaries with well defined mechanisms for creating and destroying connections and for detecting errors It is similar to phone. A connection is established between the phones (two ends) and a conversation (transfer of data) takes place. use Transmission Control Protocol (TCP) error-free data Socket pairs Communicating local and remote sockets are called socket pairs Each socket pair is described by a unique 4-tuple consisting of source and destination IP addresses and port numbers, i.e. of local and remote socket addresses Socket Functions Socket() To create a socket Bind() It’s a socket identification like a telephone number to contact Listen() Ready to receive a connection Connect() Ready to act as a sender Accept() Confirmation, it is like accepting to receive a call from a sender Write() To send data Read() To receive data Close() To close a connection