Computer Networks

VCM stands for Virtual Channel Memory, a memory technology developed by NEC that uses virtual channels to improve memory performance by reducing latency and increasing bandwidth efficiency.

ADSL stands for Asymmetric Digital Subscriber Line, a technology that provides faster internet connectivity over standard copper telephone lines. The 'asymmetric' refers to the different upload and download speeds, with download speeds typically being much faster than upload speeds.

A DSLAM (Digital Subscriber Line Access Multiplexer) aggregates multiple DSL connections from subscribers and multiplexes them onto a high-speed backbone network. It's a critical network infrastructure device that enables ISPs to efficiently serve many DSL customers over shared bandwidth.

TTL stands for Time To Live, a field in network protocols (especially IP) that limits the lifespan of a data packet. Each router decrements this value, and when it reaches zero, the packet is discarded to prevent indefinite circulation. Options A and C use 'Language' and 'Layer' incorrectly, while D is not a real technical term.

LAN stands for Local Area Network, a computer network that connects devices within a limited area such as a home, office, or building. It allows resource sharing like printers, files, and internet connections between connected computers.

In client-server networking, a client is a computer that requests resources or files from a server. A host is any device on the network, a router directs traffic, and a web server specifically serves web content.

The Internet began with ARPANET (Advanced Research Projects Agency Network) in 1969, funded by the US Department of Defense. USENET came later (1980), Ethernet was developed at Xerox PARC (1973), and Intranet is a private internet.

IEEE 802.3 is the standard working group that defines Ethernet, the most widely used local area networking technology. Broadband, fiber optic, and Bluetooth are separate networking technologies with their own IEEE standards or specifications.

ARPANET (Advanced Research Projects Agency Network) was the precursor to the modern internet, developed by the US Department of Defense. It established the foundational networking protocols that evolved into today's global internet.

Telecommuting (also called telework or remote work) refers to working from home or other locations using electronic devices to stay connected with the workplace. Teleconferencing specifically refers to virtual meetings, not the work arrangement itself. Teledynamics and Telenet are not standard terms for this concept.

SAN stands for Storage Area Network, which is a dedicated high-speed network that provides access to consolidated, block-level data storage. Option A correctly identifies this as 'Storage area network' while the other options ('Simply allow network', just repeating 'SAN', and 'nothing') are either made up expansions or meaningless.

FireWire (IEEE 1394) is a serial bus interface standard for high-speed communications and isochronous real-time data transfer. It was developed by Apple and commonly used for connecting digital devices like cameras and external hard drives. It is not a mouse, firewall, or website.

Mobile Number Portability (MNP) allows mobile subscribers to switch between service providers while retaining their existing phone number. This facility promotes competition and gives consumers the freedom to choose better services without the inconvenience of changing their contact number.

Xen is a well-known open-source virtualization software that runs directly on hardware (type-1 hypervisor). It allows multiple operating systems to run simultaneously on a single computer by creating and managing virtual machines. Xen was developed at Cambridge University and is widely used in cloud computing infrastructure, including by Amazon Web Services.