Found 1625 Articles for Computer Network

Bluetooth is a network technology that connects mobile devices wirelessly over a short-range to form a personal area network (PAN). They use short-wavelength, ultra-high frequency (UHF) radio waves within the range 2.400 to 2.485 GHz, for wireless communications.Bluetooth UsageUsage of Bluetooth can be broadly categorized into three areas −Access Points for Data and Voice − Real-time voice and data transmissions are provided by Bluetooth by connecting portable and stationary network devices wirelessly.Cable replacement − Bluetooth replaces the need for a large number of wires and cables of wired networks. The connections can be made instantly and are retained even when ... Read More

Logical Link Control and Adaptation Protocol (L2CAP) is a protocol used in the Bluetooth standard that provides adaption between higher layers and the baseband layer of the Bluetooth stack. It operates just above the host-controller interface (HCI) passing data frames from the higher layers to either HCI or Link Manager.The following diagram shows the position of L2CAP in Bluetooth protocol architecture −Functions of L2CAPAdaptation between higher-layer frames and lower layer frames of the Bluetooth protocol stack.Support for both connection-oriented as well as connectionless services.Supporting two links for the Baseband layer −Synchronous Connection-Oriented (SCO) links for real-time voice traffic using reserved ... Read More

The Bluetooth radio layer is the lowest layer of Bluetooth architecture that corresponds to the physical layer of the OSI model. It lays down the physical structure and specifications for the transmission of radio waves.The position of the radio layer depicted in the following diagram −Characteristic Features of Bluetooth Radio LayerThe Bluetooth radio layer lays down the requirements of the Bluetooth transceiver device that communicates using Bluetooth technology.It defines air interface, frequency bands, frequency hopping specifications, and modulation techniques.This layer is responsible for moving data bits from the master device to the slave device, and vice versa.It is a low-power ... Read More

Bluetooth network technology connects mobile devices wirelessly over a short-range to form a personal area network (PAN). The Bluetooth architecture has its own independent model with a stack of protocols, instead of following the standard OSI model or TCP/IP model. The protocols in the Bluetooth standard can be loosely grouped into the physical layer, data link layer, middleware layer, and application layer as shown in the following diagram − Protocols in the Bluetooth Protocol Architecture Physical Layer − This includes Bluetooth radio and Baseband (also in the data link layer. ... Read More

The IEEE 802.16 is a set of standards defining the specifications for wireless broadband technology. It has been commercialized as Worldwide Interoperability for Microwave Access (WiMAX) that is responsible for the delivery of last-mile wireless broadband access. It lays down the standards for both physical layer as well as medium access control (MAC) layer for WiMAX.The IEEE 802.16 MAC sublayer is a part of the data link layer. The data link layer of WiMAX is divided into three sublayers as follows −Security sublayer − This is the bottommost layer and is concerned with the security and privacy of the wireless ... Read More

The IEEE 802.16 set of standards lays down the specifications for wireless broadband technology. It has been commercialized as Worldwide Interoperability for Microwave Access (WiMAX) that is responsible for the delivery of last-mile wireless broadband access.The IEEE 802.16 MAC sublayer is the most important sublayer and concerned with channel management. It has been designed for connection-oriented channel management for point-to-multipoint (PMP) broadband services.The frame format of a generic MAC frame is shown below −The fields are −EC − A single-bit field indicating whether the payload is encrypted.Type − A 6-bit field identifying frame type.CI − A single-bit field denoting the ... Read More

A SAN is a network of storage devices that can be accessed by multiple servers or computers. It provides a shared pool of storage space. Each computer on the network can access the storage on the SAN as though they were local disks connected directly to the computer. SAN uses SCSI and SATA protocols.NAS are storage devices that are linked to a network and provide file access services to computer systems. These devices generally include an engine that executes the file services and one or more devices on which data is stored. NAS uses file access protocols such as NFS ... Read More

All these three protocols provide a mechanism for flow control. Read through this article to get a basic overview of Stop and Wait, Go-Back-N, and Selective Repeat protocols. Stop and Wait Protocol It is the most fundamental flow control strategy. The transmitter sends one frame at a time to the receiver using this method. The transmitter will come to a halt and wait for the receiver to respond. The interval between sending a message and receiving an acknowledgment is known as the sender's waiting time, and the sender is idle during this time. After receiving an acknowledgment (ACK), the ... Read More

The Windows Registry also holds information regarding recently accessed files and considerable information about user activities, besides configuration information. Hence, this article serves the purpose is to provide you with a depth understanding of the Registry and Wealth of information it holds. Today most administrators and forensic analysts, the registry probably looks like the entrance to a dark.Windows RegistryThe system was largely managed by several files-specifically, autoexec.bat, config.sys, win.ini (on windows) and system.ini. So, various settings within these files determined what programs were loaded and how the system looked and responded to user input, a central hierarchical database that maintains configuration ... Read More

Nmap is a free open source tool, employed to discover hosts and services on a computer network by sending packets and analyzing the retrieved responses. Nmap offers some features for probing computer networks, including host discovery and service and operating system detection.Nmap can provide further information on targets, including reverse DNS names, device types, and MAC addresses.Host discovery – Identifying hosts on a network. For example, listing the hosts that respond to TCP and/or ICMP requests or have a particular port open.Port scanning – Enumerating the open ports on target hosts.OS detection – Determining the operating system and hardware characteristics ... Read More