Huawei ICT Academy Datacom Principles

Vocabulary flashcards covering core topics in communication protocols, Huawei device commands/VRP basics, physical layer signals, media cabling, and data link layer operations from the Huawei ICT Academy course.

Syntax

A element of a network protocol that defines the structure or format of data and control information.

Semantics

An element of a network protocol that defines the control information to be transmitted, the actions to be performed, and the responses to be returned.

Synchronization

An element of a network protocol that provides a detailed description about the sequence of events during data exchange.

Internet Engineering Task Force (IETF)

A voluntary organization that develops and improves Internet protocols (especially the TCP/IP protocol suite) and updates standards by publishing RFC documents.

OSI Reference Model

A seven-layer protocol architecture defined in ISO/IEC 7498-1 comprising Application, Presentation, Session, Transport, Network, Data link, and Physical layers.

Protocol Data Unit (PDU)

A data block transmitted at each layer of the TCP/IP protocol stack, named as data at Application, segment at Transport, packet at Network, frame at Data link, and bit at Physical layer.

Data Encapsulation

The top-to-bottom process where data moves down the protocol stack and corresponding protocol control headers/trailers are added at each layer.

Data Decapsulation

The bottom-to-top process where a receiving device deletes one or more protocol headers as data moves up the protocol stack toward an application.

Versatile Routing Platform (VRP)

A universal operating system platform that serves as the software core engine for Huawei datacom products such as routers, Ethernet switches, and service gateways.

System Software

Essential software file for device startup and operation providing support and management for Huawei devices, typically using a .cc file extension.

Patch File

A software file compatible with system software used to fix system bugs, typically having a .pat file extension.

PAF File

A file used on Huawei network devices to effectively control product features and resources, typically having a .bin file extension.

Console User Interface

A physical interface allocated to manage and monitor users who directly connect a terminal serial port to a device's console port for local login access.

VTY User Interface

A Virtual Type Terminal user interface allocated to manage and monitor users logging into a network device remotely via Telnet or STelnet.

Baseband Signal

An unmodulated signal emitted by a source that contains basic frequency bands, a large proportion of low-frequency signals, and direct current (DC) signals.

Passband Signal

A signal obtained after applying carrier modulation to a baseband signal to allow transmission across complex media channels.

Non-return-to-zero (NRZ)

An encoding mode where a positive electrical level indicates a bit value of $1$ and a negative level indicates a bit value of $0$.

Return-to-zero (RZ)

An encoding mode where a positive electrical pulse indicates a bit value of $1$ and a negative pulse indicates a bit value of $0$.

Manchester Encoding

An encoding technique where a signal transition occurs at the middle of every bit period, typically using a low-to-high transition for $0$ and a high-to-low transition for $1$.

Differential Manchester Encoding

An encoding technique with a continuous mid-bit transition, where a transition at the start of a bit period represents $0$ and the absence of a transition represents $1$.

Frequency Division Multiplexing (FDM)

A channel multiplexing technique that divides the total available channel bandwidth into distinct frequency bands and allocates a unique band to each user.

Time Division Multiplexing (TDM)

A channel multiplexing technology that assigns the entire channel frequency band to different users across specific, regularly recurring timeslots.

Statistical Time Division Multiplexing (STDM)

A channel multiplexing method where timeslots are dynamically allocated on demand rather than fixedly assigned, maximizing channel utilization.

Wavelength Division Multiplexing (WDM)

Frequency division multiplexing applied specifically to optical signals, allowing multiple optical carrier signals to travel along a single optical fiber.

568A Wire Sequence Standard

A twisted pair color arrangement standard defined as: green/white, green, orange/white, blue, blue/white, orange, brown/white, and brown.

568B Wire Sequence Standard

A twisted pair color arrangement standard defined as: orange/white, orange, green/white, blue, blue/white, green, brown/white, and brown.

RJ45 Connector

An $8\text{-pin}$ modular connector standardized under IEC 60603-7 commonly used for terminating twisted pair network cables.

Multi-mode Optical Fiber

An optical fiber designed with a large core diameter of $50 candidate\text{ }\frac{1}{2} standard \rightarrow 50\text{ }\nu\text{m}$ or $62.5\text{ }\nu\text{m}$ ($50 point 0\text{ }\nu\text{m}$ / $62.5\text{ }\nu\text{m}$) that transmits light in multiple modes over shorter distances.

Single-mode Optical Fiber

An optical fiber featuring a small core diameter of $9\text{ }\nu\text{m}$ capable of single-mode transmission with low attenuation and zero mode dispersion for long distances.

Infrastructure Connection

A wireless connection topology where mobile terminal devices connect to a central Access Point (AP) to reach a wired local area network or the Internet.

Ad-hoc Connection

A decentralized wireless connection mode where terminal devices connect directly to each other without passing through an Access Point (AP).

Organizationally Unique Identifier (OUI)

The first $3\text{ bytes}$ ($24\text{ bits}$) of a MAC address assigned by the IEEE to uniquely identify a hardware manufacturer.

Unicast Frame

An Ethernet frame directed to a single unique host destination MAC address.

Broadcast Frame

An Ethernet frame addressed to FF-FF-FF-FF-FF-FF, causing all receiving nodes on the local broadcast domain to process it.

Multicast Frame

An Ethernet frame whose destination MAC address represents a designated group of devices (such as 01-80-C2-00-00-01).

Logical Link Control (LLC) Sublayer

The upper sublayer of the IEEE Data Link Layer that interfaces with the network layer to offer service access points, unified interfaces, and flow control.

Media Access Control (MAC) Sublayer

The lower sublayer of the IEEE Data Link Layer that connects directly to the physical layer, handling hardware addressing and shared media resource allocation.

CSMA/CD

Carrier Sense Multiple Access with Collision Detection; a media access control algorithm summarized as listening before sending, listening while sending, stopping upon collision, and retransmitting after a random backoff.

CSMA/CA

Carrier Sense Multiple Access with Collision Avoidance; a wireless access technology that prevents collisions using channel sensing and random backoff timers prior to transmission.

Token Ring

A deterministic collision-prevention technology where a station must hold a passing token to gain exclusive frame transmission rights on a ring topology.

Frame Check Sequence (FCS)

A $4\text{-byte}$ field placed in the trailer of an Ethernet frame containing a Cyclic Redundancy Check value to verify data frame integrity.