Network hardware

The next level is the protocol that governs how the data are transmitted over the wire. Many protocols are ia use. A typical iastaHatioa may have multiple protocols mnning simultaneously on the same physical network. Vendors of network hardware and software develop protocols that are optimized for the type of appHcation for which their product is targeted. Among the protocols commonly seen ia a prepress aetwork are Apple Computer s AppleTalk and EtherTalk, and TCP/IP used by many UNIX work station vendors. The appHcation software a user employs automatically uses whatever protocol is necessary to move information over the network. 

Not only the number of messages that can pass along one fibre, but also the speed of transmission, has increased steadily over the past two decades according to Sato (2000), in Japan this speed has increased by about an order of magnitude per decade, as a consequence of improved fibres and lasers and also improved networking hardware. 

All aspects, including application, operating system, network hardware, etc., must be considered in determining the nature of electronic systems. As indicated above, the main difference between an open and a closed system is simply access. If you have a chromatography data system that operates within your department, the system is closed. The system is closed even if the IT Department runs the server and maintains the network. The system remains closed even if you outsource the IT support to a third-party provider, provided no other company s work interferes with yours. 

Develop and implement rigorous configuration management and change control procedure for all your network hardware and software. This should also include updates of system drawings if there are any changes. 

IT stands for Information Technology. It refers to the whole computing technology and industries related to it, such as networking, hardware, software, the Internet, or the people that work with these technologies. 

Servers Workstations Network Hardware Controllers I/O Racks I/O Cards Barrier Systems Field Instruments Power Supplies... 

Data integrity verihcation — ensure network hardware and software include error checking, handling, and correction measures commensurate with the applications the network supports (e.g., parity checking, checksum and cyclic redimdancy checks and transaction roll-back after network failure should be facilitated critical data files may be stored in duphcated separate locations)... 

Organizational network hardware and software installation and changes (for cabling, bridges, routers, etc.)... 

Are change control procedures in place to manage changes to network hardware, firmware and software, including impact assessment of any application affected by change ... 

The content of networks specification and test protocols will depend on the complexity of the system. For small systems it may be possible to incorporate the design of the network as a special section within the Systems Functional Specification, and similarly incorporate the network test cases as a special section within the systems. Operational Qualification Supplier audits for network hardware and software components are not usually necessary as these are normally industry standard. Further discussion in regard to supplier audits can be found in Chapter 7. 

Network GAMP (2001) A network is a data communications system that links two or more computers and peripheral devices. It consists of cabling, the network hardware, and communications software. 

I n this chapter, you learned about the various network hardware topics that you will be tested on in the A+ exam. A few years ago, you never saw many computers with network cards come in for service. Networks were found only in offices and large companies. Now networks can be found in many homes. For this reason, the A+ exam requires that you have at least a basic understanding of network hardware. 

Application layer The seventh, or highest, layer in the International Organization for Standardization s Open Systems Interconnection (ISO/OSI) model for computer-to-computer communications. This layer uses services provided by the lower layers, but is completely insulated from the details of the network hardware. It describes how application programs interact with the network operating system, including database management, e-mail, and terminal emulation programs. 

NetBIOS Acronym for Network Basic Input/Output System. In networking, a layer of software, originally developed in 1984 by IBM and Sytek, that links a network operating system with specific network hardware. NetBIOS provides an application program interface (API) with a consistent set of commands for requesting lower-level network services to transmit information from node to node. 

With the explosion of the Internet into the service world, the line between a service technician and networking technician has blurred. Frequently, computers that come in for service have problems that are related to their networking hardware. An A+ certified technician should know how both the hardware and software components of networking can affect the operation of the computer. CompTIA has put basic networking concepts on the A+ Core Hardware exam, and they make up 10 percent of the total exam questions. 

Supplier audits for network hardware and software components are not usually necessary as these are normally an industry standard. 

Payload type analysis Most locations will require at least voice and data service. Videoconferencing and multimedia may need to be supported as well. All payload types should be considered and documented prior to circuit and networking hardware selection. 

Artificial neural networks Hardware and software that are based on a model of neural synapse data processing. 

Ebay s PayPal online payments system also failed a few times in August 2009 outages lasted from one to more than four hours, leaving millions of customers unable to complete transactions. A network hardware problem was reported to be the culprit. PayPal lost millions of dollars, and merchants lost unknown amounts. Thomas Wailgum of CIO.com reported in January 2009, that Salesforce.com had suffered a service disruption for about an hour on January 6 when a core network device failed because of memory allocation errors. 

Vulnerabilities can be located at network, hardware and software level. Hardware vulnerabilities are especially a challenge for security engineering if parts of the embedded systems are employed in a potentially not trustworthy environment. In addition, hardware could generally be equipped with additional malicious components [17]. Reconfigurable means a microcontroller is reprogrammable. This could be because one step in the commissioning process has not been executed. With not tamper proof hardware, an attacker could access hardware components and execute direct attacks on the hardware. 

Frounchi J, Karimian G, Keshtkar A (2009) An Artificial Neural Network Hardware for Bladder Cancer. European Journal of Scientific Research 27 46—55... 

---