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Computer Networking

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OSI Model

Routing protocols. Connected: An Internet Encyclopedia. Lecture - Networking. The Next WiFi Rockstar by NSA Show. EtherealMind - Software Defined Networking, Data Centre and Infrastructure. Tech search engines. Physical Layer. Computer networking - Vocabulary List. Local area network (LAN) Cisco Security Appliance Command Line Configuration Guide, Version 8.0 - Glossary [Cisco ASA 5500-X Series Next-Generation Firewalls] Security association.

Cisco Security Appliance Command Line Configuration Guide, Version 8.0 - Glossary [Cisco ASA 5500-X Series Next-Generation Firewalls]

An instance of security policy and keying material applied to a data flow. SAs are established in pairs by IPSec peers during both phases of IPSec. SAs specify the encryption algorithms and other security parameters used to create a secure tunnel.

Wide area network (WAN)

Welcome to Network Tunneling Protocols. How to Configure a Cisco Vpn: 8 Steps. Network emulation. Network Layer. Network simulation. Computer Network and Communications. Computer Networks and Communications Related Book Categories: An Introduction to Computer Networks (Peter L.

Computer Network and Communications

Dordal) This is a general-purpose textbook about computer networking, complete with diagrams and exercises. It presents basic principles and concepts, along with examples to illustrate how the principles can either enable or neutralize exploits. Bits, Signals, and Packets: Digital Communications and Networks An introduction to several fundamental ideas in electrical engineering and computer science, using digital communication systems as the vehicle. Switches, Routers, Bridges and LANs.

Data link layer

ICTs: device to device communication. This unit looks at communication systems where devices are the main players, passing information to and from each other and possibly acting on that information to produce some kind of outcome.

ICTs: device to device communication

In these interactions, people may not be involved at all, or may have roles that are limited only to the initial setting of schedule (such as when certain tasks should be performed) and parameters (such as particular conditions that should be satisfied before a task is performed). Some people may see this as liberating – relieving humans from the tedious tasks of everyday living. Some may see it as threatening – taking control away from humans and placing it with the computers and machines. How do devices ‘talk’ to each other? What technologies and processes are involved? We then look at wired and wireless communication technologies, introducing you to some of the key methods currently in use. Digital communications - OpenLearn - Open University - T305_1.

This unit is from our archive and it is an adapted extract from Digital Communications (T305) which is no longer in presentation.

Digital communications - OpenLearn - Open University - T305_1

If you wish to study formally at The Open University, you may wish to explore the courses we offer in this curriculum area.47 [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip48)] By using optical fibre, very high data rates (gigabits per second and higher) can be transmitted over long distances (tens of kilometres) without amplifiers or regenerators. Optical fibre has completely superseded copper wires as the primary medium for cabled transmission over long distances.

As demand for capacity has risen, fibre is now being used even in LANs and the access network. Articles. Netstat. Displays active TCP connections, ports on which the computer is listening, Ethernet statistics, the IP routing table, IPv4 statistics (for the IP, ICMP, TCP, and UDP protocols), and IPv6 statistics (for the IPv6, ICMPv6, TCP over IPv6, and UDP over IPv6 protocols).


Used without parameters, netstat displays active TCP connections. Syntax. Using the ping command. Updated: August 22, 2006 Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2 If you are having connectivity problems, you can use the ping command to check the destination IP address you want to reach and record the results.

Using the ping command

The ping command displays whether the destination responded and how long it took to receive a reply. If there is an error in the delivery to the destination, the ping command displays an error message. Linktionary Major Topics Index. IPv6. Internet Protocol version 6 (IPv6) is the most recent version of the Internet Protocol (IP), the communications protocol that provides an identification and location system for computers on networks and routes traffic across the Internet.


IPv6 was developed by the Internet Engineering Task Force (IETF) to deal with the long-anticipated problem of IPv4 address exhaustion. IPv6 is intended to replace IPv4.[1] Every device on the Internet is assigned an IP address for identification and location definition. With the rapid growth of the Internet after commercialization in the 1990s, it became evident that far more addresses than the IPv4 address space has available were necessary to connect new devices in the future. By 1998, the Internet Engineering Task Force (IETF) had formalized the successor protocol. IPv6 provides other technical benefits in addition to a larger addressing space. Main features[edit] Decomposition of the IPv6 address representation into its binary form IPv4[edit]

IPv4. Internet Protocol version 4 (IPv4) is the fourth version of the Internet Protocol (IP).


It is one of the core protocols of standards-based internetworking methods in the Internet, and was the first version deployed for production in the ARPANET in 1983. It still routes most Internet traffic today,[1] despite the ongoing deployment of a successor protocol, IPv6. IPv4 is described in IETF publication RFC 791 (September 1981), replacing an earlier definition (RFC 760, January 1980).

Differentiated services. Differentiated services or DiffServ is a computer networking architecture that specifies a simple, scalable and coarse-grained mechanism for classifying and managing network traffic and providing quality of service (QoS) on modern IP networks.

Differentiated services

DiffServ can, for example, be used to provide low-latency to critical network traffic such as voice or streaming media while providing simple best-effort service to non-critical services such as web traffic or file transfers. Background[edit] Traffic management mechanisms[edit] DiffServ is a coarse-grained, class-based mechanism for traffic management. In contrast, IntServ is a fine-grained, flow-based mechanism. DiffServ operates on the principle of traffic classification, where each data packet is placed into a limited number of traffic classes, rather than differentiating network traffic based on the requirements of an individual flow. DiffServ domain[edit] Explicit Congestion Notification. Explicit Congestion Notification (ECN) is an extension to the Internet Protocol and to the Transmission Control Protocol and is defined in RFC 3168 (2001).

Explicit Congestion Notification

ECN allows end-to-end notification of network congestion without dropping packets. ECN is an optional feature that may be used between two ECN-enabled endpoints when the underlying network infrastructure also supports it. Conventionally, TCP/IP networks signal congestion by dropping packets. When ECN is successfully negotiated, an ECN-aware router may set a mark in the IP header instead of dropping a packet in order to signal impending congestion. CS402: Computer Communications and Networks. The Internet has become one of the most important components of our life. We browse the Web, check e-mails, make VoIP phone calls, and have video conferences via computers. All of these applications are made possible by networking computers together, and this complex network of computers is usually referred to as the Internet. This course is designed to give you a clear understanding of how networks, from in-home local area networks, or LANS, to the massive and global Internet, are built and how they allow us to use computers to share information and communicate with one another.

Unit 1 introduces you to an explanation of what computer networks are as well as to some basic terminology fundamental to understanding computer networks. You will also familiarize yourself with the concept of layers, which compose the framework around which networks are built. This course is designed to align with a Thomas Edison State College TECEP examination. Computer Networking: Principles, Protocols, and Practice (Release 0.25) Welcome to The TCP/IP Guide!

Transport layer protocols

List of TCP and UDP port numbers. This is a list of Internet socket port numbers used by protocols of the transport layer of the Internet Protocol Suite for the establishment of host-to-host connectivity. Originally, port numbers were used by the Network Control Program (NCP) in the ARPANET for which two ports were required for half-duplex transmission. Later, the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP) needed only one port for full-duplex, bidirectional traffic. The even-numbered ports were not used, and this resulted in some even numbers in the well-known port number range being unassigned. The Stream Control Transmission Protocol (SCTP) and the Datagram Congestion Control Protocol (DCCP) also use port numbers. They usually use port numbers that match the services of the corresponding TCP or UDP implementation, if they exist.

Application layer protocols

Computer Sc - Internet Technologies. Computer Science and Engineering - Computer Networks. Upload nptelhrd Loading... Working... ► Play all.