Computer Networks

A NIC (Network Interface Card) is the hardware component that installs in a PC and enables it to connect to a network. It provides the physical interface between the computer and network medium. Hubs and routers are external network devices, not expansion cards installed inside PCs, while graphic accelerator cards are for video processing, not networking.

Network planning should prioritize flexibility and future expansion. Technology evolves rapidly, so choosing scalable, upgradable products protects your investment. Backup for all devices (A) is cost-prohibitive, telephone lines per PC (C) is unnecessary for networks, and fastest cabling (D) may be overkill if obsolescence comes from protocol changes rather than cabling speed limits.

A dual 10/100 Mbps Ethernet NIC is designed to support both legacy 10 Mbps networks and newer 100 Mbps Fast Ethernet networks. This provides upgrade flexibility - the same card works if you upgrade from 10 Mbps to 100 Mbps infrastructure. It doesn't enable remote access (A), can't function as a hub (B), and uses standard Ethernet cabling, not cable lines (D).

A modem (modulator-demodulator) enables computers to communicate over telephone lines and access the internet. RAM is temporary memory, CD-DRIVE is optical storage, and HARD-DRIVE is permanent storage - none of these facilitate network communication. The modem's specific purpose is converting digital signals to analog for telephone line transmission.

The correct answer is E (None of the above) because BlackBerry devices support all the listed connectivity options: Wi-Fi for wireless networks, Bluetooth for short-range connections, Tethered Modem for using the device as a modem, and GPS for location services. Since all options A through D are supported by BlackBerry, the correct choice is 'None of the above' - meaning none of these are unsupported.

This code creates infinite recursion by calling main() from within mainn(), which in turn calls main() again. Each call adds a new stack frame without ever returning, eventually consuming all available stack space and causing stack overflow. The loop continues until the stack memory is exhausted, not underflow or machine hang.

SANs (Storage Area Networks) commonly use Fibre Channel as the underlying transport protocol due to its high speed, reliability, and block-level storage access capabilities. While iSCSI and other protocols exist, Fibre Channel remains the traditional SAN topology.

Both SAN (Storage Area Network) and NAS (Network Attached Storage) are network storage systems that enable data sharing over high-speed LAN connections. SAN provides block-level storage while NAS provides file-level storage, but both serve the purpose of shared network data access.

The term Host Bus Adapter (HBA) is most commonly used to refer to Fibre Channel interface cards that connect a host system to a storage area network (SAN). Other adapters like iSCSI, SAS, or Ethernet cards use different interface terminologies.

Cisco, Brocade (acquired by Broadcom), and QLogic are major Fibre Channel switch manufacturers. D-Link primarily produces consumer networking equipment and is not a significant player in enterprise Fibre Channel switching.

A modem (modulator-demodulator) converts digital signals from a computer into analog signals for transmission over telephone lines, and converts incoming analog signals back to digital form. ISDN, DSL, and HDSL are digital communication technologies that don't perform this conversion - they transmit digital signals directly. The modem's core function is this digital-analog conversion, which is essential for traditional analog phone line communications.

Statement D is false because applications CAN be shared over a LAN. Local Area Networks are specifically designed to allow resource sharing including applications, files, and printers. Statements A, B, and C are all true statements about networks.

In networking, attenuation (signal weakening over distance) determines the maximum number of nodes per segment because each node adds cable length and signal degradation. Once signal strength drops below threshold, the segment becomes unreliable. Bandwidth and throughput affect data speed, regeneration is the solution (adding repeaters), not the limiting factor.

Circuit-switched networks (like traditional telephone networks) establish a dedicated communication path with reserved resources (bandwidth, buffers) for the entire circuit duration. This guarantees quality but wastes resources when idle. This fundamental characteristic distinguishes circuit switching from packet switching, which shares resources dynamically.

Thicknet refers to the thick coaxial cable standard in Ethernet, officially designated as 10Base5 by IEEE. The '10' means 10 Mbps, 'Base' means baseband transmission, and '5' indicates 500 meter maximum segment length. 10Base2 is Thinnet (thin coaxial), and 10BaseT uses twisted-pair copper.