본문 바로가기

네트워크13

2.2 The Web and HTTP 2.2.1 Overview of HTTP The HyperText Transfer Protocol (HTTP), the Web’s application-layer protocol, is at the heart of the Web. HTTP is implemented in two programs: a client program and a server program. The client program and server program, executing on different end systems, talk to each other by exchanging HTTP messages A Web page (also called a document) consists of objects. An object is s.. 2023. 7. 19.
2.1.3 Transport Services Available to Applications Many networks, including the Internet, provide more than one transport-layer protocol. When you develop an application, you must choose one of the available transport-layer protocols The situation is similar to choosing either train or airplane transport for travel between two cities. We can broadly classify the possible services along four dimensions: reliable data transfer, throughput, timing,.. 2023. 7. 18.
Chapter 2 Application Layer 2.1 Principles of Network Applications Thus, when developing your new application, you need to write software that will run on multiple end systems. Keep in mind that an application’s architecture is distinctly different from the network architecture From the application developer’s perspective, the network architecture is fixed and provides a specific set of services to applications. The applic.. 2023. 7. 15.
1.6 Networks Under Attack The Bad Guys Can Put Malware into Your Host Via the Internet Once malware infects our device it can do all kinds of devious things, including deleting our files and installing spyware that collects our private information such as social security numbers, passwords, and keystrokes, and then sends this (over the Internet, of course!) back to the bad guys. Viruses are malware that require some form.. 2023. 7. 13.
Protocol Layering each layer provides its service by (1) performing certain actions within that layer and by (2) using the services of the layer directly below it. The application layer is where network applications and their protocols reside, such as HTTP for web document transfer, SMTP for email transfer, and FTP for file transfer. It also includes the domain name system (DNS) for translating human-friendly nam.. 2023. 7. 13.
1.4.4 Throughput in Computer Networks The instantaneous throughput at any instant of time is the rate (in bits/sec) at which Host B is receiving the file. If the file consists of F bits and the transfer takes T seconds for Host B to receive all F bits the average throughput of the file transfer == F/T bits/sec. Rs < Rc : the bits pumped by the server will “flow” right through the router and arrive at the client at a rate of Rs bps, .. 2023. 6. 20.
1.4 Delay, Loss, and Throughput in Packet-Switched Networks 1.4.1 Overview of Delay in Packet-Switched Networks The most important of these delays are the nodal processing delay, queuing delay, transmission delay, and propagation delay; together, these delays accumulate to give a total nodal delay. Processing Delay The time required to examine the packet’s header and determine where to direct the packet is part of the processing delay. Queuing Delay At t.. 2023. 6. 11.
1.3.3 A Network of Networks (p.58~) The access ISP can provide either wired or wireless connectivity, using an array of access technologies including DSL, cable, FTTH, Wi-Fi, and cellular. access ISP does not have to be a telco or a cable company; instead it can be, for example, a university (providing Internet access to students, staff, and faculty), or a company (providing access for its employees). Network Structure 1, intercon.. 2023. 6. 11.
Queuing Delays and Packet Loss p.51~ The output buffers play a key role in packet switching in addition to the store-and-forward delays, packets suffer output buffer queuing delays Forwarding Tables and Routing Protocols how does the router determine which link it should forward the packet onto? Packet forwarding is actually done in different ways in different types of computer networks. When a source end system wants to send a pac.. 2023. 6. 7.
3.2 Multiplexing and Demultiplexing -P.230~ 1. 목적 host에서 transport layer 는 바로 아래에 있는 network layer로부터 segments를 받는다. 2. transport layer 는 host에서 운영되고 있는 application process에 segments안에 있는 데이터들을 배달해줄 책임이있다. 1. 받는 host안에 있는 transport layer는 데이터들을 직접적으로 process에 전달하지 않는다. 대신 socket이 이일을 대신한다. 2. demultiplexing : transport layer segment 안에 있는 데이터를 올바른 socket에 전달하는 작업. ex) BILL이 집배원한테 편지를 받으면 이편지가 어느 address에서온 편지인지 확인하고 친구 B에 전달하는 작업을 demulti.. 2023. 5. 25.
728x90