by Dinesh Thakur Category: Network Technologies

Ethernet on the WAN aims to transport Ethernet frames over long distances like states, countries, or the whole world, while providing quality service. Its advantages are a very low cost, the possibility of oversizing of the network, highly granular, well known technology and very simple and finally simplified management, since Ethernet is everywhere. You can go very fast in throughput with different levels of 1 and 10 Gbit/s and soon the 100 Gbit/s. The register of difficulties include the lack of reliability, packet loss less controlled and quality of services more difficult to obtain. However, several technologies are currently being developed to address these issues and provide a royal way for the arrival of Ethernet on the WAN.

 
by Dinesh Thakur Category: Network Technologies

After invading the world of business, Ethernet addresses the longer distances starting with the metropolitan area. The Metro Ethernet was born of this extension. This solution is supported in different settings but especially by the Forum MEF (Metro Ethernet Forum).

 
by Dinesh Thakur Category: Network Technologies

SONET (Synchronous Optical Network) is a physical level standard, proposal by Bellcore (Bell Communications Research) in the mid-80s for transmission through an optical fiber. SONET is a technique of transport between two nodes, which defines the interface adopted for the NNI (Network Node Interface). Standardized by the ANSI and recommended worldwide by the CCITT, SONET can be thought of as a physical network for a global communication system in the same way that a twisted pair LAN can see as the communication system of a corporate network. It is a potentially global network, built on fiber optic cable, with standardized data transmission speeds and recognized worldwide. SONET eliminates limits between telephone companies worldwide.

 
by Dinesh Thakur Category: Network Technologies

The LAP-F protocol (Link Access Protocol-Frame) was born with frame relay, designed to improve the performance of networks from the X.25 recommendation UITT. The latter has proved too heavy and therefore unable to increase rates, it took in search for a simplification.



 
by Dinesh Thakur Category: Network Technologies

The frame level (layer 2) is to render a service to the next level just. This service is a transport node to node packet. Specifically, its role is to transport a package of three or message fragment layer of layer 4 from one node to another node. For this, the frame level asks his turn at just below, the physical level, a service of conveying the bits of the frame from one node to another node. This section provides the features necessary to achieve all these actions.

 
by Dinesh Thakur Category: Network Technologies

Applications that are conventionally used on terminal equipment put in implement a point-to-point communication, that is to say the part of the communication micro to go look for information to only one other point. Many other applications involve the cooperation of several processes. For example, a search in a distributed database in which information is spread across multiple sites, uses a simultaneous request for information to several centers. To make this request, the application and all associated protocol layers must manage multipoint. This way of communicating is more powerful than that which is to apply a first site, and once the response, a second, and so on.



 
by Dinesh Thakur Category: Network Technologies

The application of methods derived from INFORMATION THEORY to the detection and correcting of errors in DIGITAL data streams. Error correction is of the utmost importance in most areas of computing and communications technology. For example: Internet's TCP protocol provides error detection, CD-ROMS devote around 14% of their total data capacity to redundant error correction information (and music CDS only a little less), and modem speeds above 28 kilobits per second would be impossible over public telephone lines without error correcting PROTOCOLS such as v.90.



 
by Dinesh Thakur Category: Network Technologies

(xDSL) A whole class of digital telecommunication technologies that can offer BROADBAND data rates, up to 50 megabits per second (Mbps), over the existing copper wires of the analogue public telephone system. By employing advanced modulation schemes, xDSL technologies support Internet or other data access simultaneously with voice telephone calls. In the meta-acronym xDSL, the x stands for the first letter of any of the individual acronyms used for these technologies: ADSL, HDSL, SDSL and VDSL.

 
by Dinesh Thakur Category: Network Technologies

In the world of asynchronous communication (over Mac or PC serial ports), CTS stands for clear to send. When a computer needs to communicate with an outside device physically connected to it (peripheral), the two of them have to go through this preamble of making sure each of them is ready to hear what the other has to say, and confirm that they are going to be speaking the same language. Somewhere near the beginning of this preamble, one device will send an RTS (Request To Send) message. The receiving device will then reply with a CTS message "Yes, I'm now ready for anything you want to send me." I know, the whole thing sounds like you may be sitting there drumming your fingers on your desk, waiting for these flipping machines to get done with their senseless checklist. Relax. Like most processes done by a computer, this one takes less than a millisecond.



 
by Dinesh Thakur Category: Network Technologies

BBS (Bulletin Board System): A single computer running special communications software that acts as a kind of electronic bulletin board. That allows remote users to dial in via a public telephone line to exchange messages and chat with one another. which is a service usually set up by an organization or a club to provide or exchange informationA BBS allows multiple people to use it at the same time in order to exchange ideas, offer help with software problems, and converse (through typed conversations) with other users currently connected to the BBS. You access the BBS through your modem , a device that transmits data through ordinary telephone lines. While connected to a BBS, a user can share information with other computer users, leave messages, and upload and download programs. One popular BBS is the Boston Computer Exchange, a place where members can buy, sell, or trade computers. Pay-for-use information services, such as CompuServe, Prodigy, and Internet are like BBS, but much larger. There are thousands of other BBSs across the globe offering a variety of topics and interests ranging from software support to dating services. To communicate with other computers, a modem is necessary.



 
by Dinesh Thakur Category: Network Technologies

AAL (ATM Adaptation Layer) is a third example message level protocol. A software layer that accepts user data, such as digitized voice, video or computer data, and converts to and from cells for transmission over an ASYNCHRONOUS TRANSFER MODE network. AAL software mostly runs at the end-points of a connection, though in a few circumstances AAL software is run inside an ATM switch. AAL includes facilities to carry traffic that uses other network protocols, such as TCP/IP, over ATM.



 
by Dinesh Thakur Category: Network Technologies

Definition: Asynchronous Transfer Mode (ATM) also called cell relay (transferring data in cells of a fixed size) that is operates at the data link layer (Layer 2) of OSI Model over fiber or twisted-pair cable, a high-speed switched network technology based on ITU-T Broadband Integrated Services Digital Network (B-ISDN) standard, developed by the telecommunications industry to implement the next generation network. ATM was designed for use in WANs such as the public telephone system and corporate data networks, though it has also been applied to create super-fast LANs.

 
by Dinesh Thakur Category: Network Technologies

ISDN provides two basic types of interfaces to users.

  1. Basic Rate Interface (BRI)
  2. Primary Rate Interface (PRI)
 
by Dinesh Thakur Category: Network Technologies

Products for ISDN technology from different vendors even with similar features and options may create some compatibility issues. CCITT after good deliberations over the years published the first significant ISDN standards in a number of red binders in 1984 and they were simply known as the Red Book standards. The group subsequently met four years later which culminated in the publication of the 1988 Blue Book standards. These international publications were the foundation for the evolving ISDN national standards. The CCITT eventually was reformed into the group, which is now called the ITU- T. The standards used to define ISDN make use of the OSI reference model with the first three layers of this OSI reference model.

 
by Dinesh Thakur Category: Network Technologies

Integrated Services Digital Network (ISDN) is a set of CCITT /ITU standards for digital transmission over ordinary telephone copper wire as well as over other media. This technology uses ISDN adapters in place of modems and provides very fast speed up. ISDN requires adapters at both ends of the transmission.

 
by Dinesh Thakur Category: Network Technologies

The earliest electronic network is the telephone system. This telephone network commonly uses analog technology that was quite different from digital technology used in the computer-based networks. The advantages of digital technology over the analog technology in terms of economics and services forced the telephone industry to move rapidly to install fiber and digital networks.

 
by Dinesh Thakur Category: Network Technologies

The broadcast systems generally allow the possibility of addressing a packet to all destinations by using a special code in the address field. When a packet with this code is transmitted then it is received and processed by every machine on the network. This mode is called broadcasting.

 
by Dinesh Thakur Category: Network Technologies

When data is sent to the receiver, flow control should be carried out so that the flow of data does not overwhelm the receiver. Any receiving device has a limited speed at which it can process the incoming data and a limited amount of memory to store the incoming data. The receiving device should be able to inform the sending device before these limits are reached so that the transmission is stopped or reduced, temporarily.

 
by Dinesh Thakur Category: Network Technologies

Frame Relay (frame relay) is a packet switching technology that fragmented into transmission units called frames and sent in high-speed bursts through a digital network. Establishes an exclusive connection during the transmission period called virtual connection.

 
by Dinesh Thakur Category: Network Technologies

• X.25 is a standard used by many older public networks specially outside the U.S.
• This was developed in 1970s by CCITT for providing an interface between public packet-switched network and their customers.
• The packet switching networks use X.25 protocol. The X.25 recommendations were first prepared in1976 and then revised in1978,1980 and 1984.



 

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About Dinesh Thakur

Dinesh ThakurDinesh Thakur holds an B.SC (Computer Science), MCSE, MCDBA, CCNA, CCNP, A+, SCJP certifications. Dinesh authors the hugely popular blog. Where he writes how-to guides around Computer fundamental , computer software, Computer programming, and web apps. For any type of query or something that you think is missing, please feel free to Contact us.