Computer Networks

Clique in Teradata is a physical grouping of Nodes (hardware units) that share disk arrays. If one node fails, another node in the clique can take over its AMPs and access the same disk storage. Clique is NOT composed of Gateways, PEs, or AMPs - those are software components running on nodes.

A computer port serves as a physical or virtual interface point that allows the computer to communicate with peripheral devices such as printers, keyboards, mice, and external storage. Ports provide the necessary connection points for data transfer between the computer's internal systems and external hardware components. The other options are incorrect because downloading files requires network connectivity not just a port, communicating with all hard drives uses internal interfaces like SATA/IDE not ports, and connecting computers together typically requires network cards or crossover cables.

DSL (Digital Subscriber Line) provides high-speed internet over standard telephone lines. Unlike dial-up, DSL allows simultaneous internet and voice usage. GUI, HTML, and FTP are unrelated to high-speed internet connection technology.

Grid computing capabilities require physical infrastructure support from hardware vendors (servers, storage, networking equipment) and operating systems (resource management, clustering, virtualization). Hardware provides the physical resources, while operating systems manage and pool these resources. Developers and DBAs work at higher abstraction layers, while network/transport layers are communication protocols, not Grid infrastructure providers.

Router transformation splits data into multiple output groups based on group conditions. You can connect multiple output groups to the same downstream target or transformation (e.g., send multiple groups to one target table). This is different from other rules - Router's unique capability is that multiple groups can route to the same destination. The other options are incorrect: you cannot connect multiple groups to a multiple-input transformation except Joiner; you cannot connect multiple output ports in one group to multiple transformations in the same connection; and you're not limited to one group per transformation.

In Informatica Aggregator transformation, aggregate operations (SUM, AVG, COUNT, etc.) are performed on the output port. The input ports receive raw data, variable ports can perform intermediate calculations, but only the output port defines the aggregate result that gets passed to the next transformation.

In Rogers Telecommunications, customer calls are forwarded to agents through a system infrastructure consisting of PBX (Private Branch Exchange), LAN (Local Area Network), and Host Computer. The PBX handles call routing, the LAN connects the system components, and the host computer manages the call data and agent interactions. SPI, OmniVox3D Application layer, and CTI (Computer Telephony Integration) are related technologies but not the complete forwarding path.

Infrastructure applications are foundational software systems that support core IT operations. A VPN provides secure network communication infrastructure, network management systems monitor and control infrastructure, email is fundamental communication infrastructure, and office productivity software (while end-user facing) is part of the standard software infrastructure in organizations. All these represent different layers of IT infrastructure.

Microsoft systems typically use CIFS (Common Internet File System) to connect to NAS for file sharing. NFS (Network File System) is typically used by Unix/Linux systems. BDMP and DART are not standard file sharing protocols.

The Fibre Channel switch provides physical connections and logical routing between devices in a SAN fabric. Fibre cable is just the physical medium. HBA (Host Bus Adapter) connects servers to the fabric. Storage array contains the actual storage devices. The switch is the intelligent component that routes traffic.

FC arbitrated loop (FC-AL) is the topology that uses hubs to connect devices in a loop, with arbitrated access to the loop. Switched fabric uses switches, not hubs. Mesh topologies (full or partial) require point-to-point connections between devices, not hub-based architecture. The hub is the defining characteristic of arbitrated loop topology.

NAS (Network Attached Storage) provides file-level storage consolidation for multiple servers, while SAN (Storage Area Network) provides block-level storage consolidation. Option A correctly identifies this distinction. Options B, C, and D are reversed: SAN uses block-level protocols (FC, iSCSI), NAS uses file-level protocols (NFS, SMB), NAS uses TCP/IP, SAN uses FC, and both support multipathing capabilities.

The Host Bus Adapter (HBA) is the hardware component that physically and logically connects a host computer's I/O bus (such as PCI) to a Fibre Channel network. It acts as the interface card installed in the server, converting protocol and electrical signals between the host system and the SAN fabric. Fibre cables simply transmit data, switches route traffic, and storage arrays store data - only the HBA provides the actual connection point from the host to the network.

Single-mode fiber for ISLs (Inter-Switch Links) in Fibre Channel networks can support distances up to approximately 20 kilometers. Single-mode fiber uses a single light path and laser light sources, allowing for longer distances with less signal attenuation compared to multi-mode fiber. The 20 km distance is a standard specification for long-wave laser transceivers in SAN environments.

Multi-mode fiber for ISLs (Inter-Switch Links) in Fibre Channel networks typically supports distances up to 500 meters. Multi-mode fiber uses multiple light paths and LED or laser sources, which causes modal dispersion that limits effective distance. For longer ISL distances, single-mode fiber must be used instead. The 500 meter distance is the standard limit for multi-mode in SAN environments.