Computer Networks

Bluetooth prevents interference through Frequency-Hopping Spread Spectrum (FHSS). Devices hop 1600 times/second across 79 channels, so collisions are brief and retransmission handles them. L2CAP is a protocol layer above. 'Air sniffing' is not a Bluetooth term. Note: option has typo 'Hoping' instead of 'Hopping'.

Blue bugging is a Bluetooth security attack where an unauthorized remotely connects to a Bluetooth-enabled phone to make calls, access data, or eavesdrop. Blue tagging and blue error are not standard Bluetooth security terms. This vulnerability exists in devices with vulnerable Bluetooth implementations.

Bluetooth technology is standardized under IEEE 802.15, which covers wireless personal area networks (WPANs). 802.11 is for Wi-Fi (WLAN), 802.16 is for WiMAX (wireless broadband), and 802.3 is for Ethernet (wired). Bluetooth uses the 802.15.1 specification specifically.

NIC stands for Network Interface Card. It's the hardware component that connects a computer to a network. The other options misrepresent this standard acronym - Communication and Networking are not what the 'I' stands for.

FDDI stands for Fiber Distributed Data Interface, a standard for data transmission on fiber optic lines in a local area network (LAN). Option B is correct. It was developed by ANSI and supports data rates up to 100 Mbps. Option A has 'Data' and 'Distributed' in wrong positions. Option C incorrectly says 'Digital' instead of 'Data'. Option D has 'Digital' and misspells 'Distributed' as 'Ditributed'.

SONET is a standard for synchronous data transmission over optical fiber. The correct expansion is Synchronous Optical Networking (option D). Options A and B incorrectly use 'Service' or 'Simple', and option C incorrectly uses 'Optics' instead of 'Optical'.

SAN stands for Storage Area Network, which is a dedicated, high-speed network that provides block-level network access to storage devices.

In Informatica PowerCenter, lookup transformations are broadly classified into two main operational types: connected (integrated into the mapping pipeline) and unconnected (called from an expression).

MQI (Message Queue Interface) is an API that applications use to interact with queues - it's not a channel at all. MQI calls are made by applications locally to the MQ client libraries, which then communicate over channels. The actual channels used for communication between Queue Managers are Message Channels (MCA channels), not MQI channels. MQI channels don't exist as a concept.

Message Channels in IBM MQ are unidirectional - they transfer messages in one direction only. A Sender channel sends messages from one Queue Manager to another, while a Receiver channel receives them. For bidirectional communication, you need two separate channels (a sender/receiver pair in each direction).

Transmission queues are specialized local queues in MQ that store messages destined for remote queue managers. Each remote queue definition can specify its own transmission queue, applications cannot directly access them, and their name conventionally matches the remote queue manager name.

Bursting is the feature that enables delivering a single report to multiple destinations simultaneously. Distributing typically refers to data distribution, broadcasting is one-to-many communication, and copying creates duplicates.

Flow control occurs at the transport layer (Layer 4), where mechanisms like TCP's sliding window prevent a fast sender from overwhelming a slow receiver. This ensures reliable data delivery. While the MAC sublayer has some flow control (e.g., Ethernet pause frames), the primary flow control is at the transport layer.

Packets are the protocol data units (PDUs) at the network layer (Layer 3), which handles routing and logical addressing (IP addresses). The data link layer uses frames, the transport layer uses segments, and the physical layer deals with bits. This is a fundamental OSI model concept.

The network layer (Layer 3) translates between physical (MAC) addresses used for local delivery and logical (IP) addresses used for routing across networks. Protocols like ARP (Address Resolution Protocol) operate here to map IP addresses to MAC addresses for delivery on the local network segment.