4. Glossary

ACL: An Access Control List (ACL) is a set of rules that define who can access a resource and what actions they can perform.
API: Application Programming Interface
ASLR: Address-Space Layout Randomization (ASLR) is a security technique that protects against buffer overflow attacks by randomizing the location of executables in memory.
BSD: Berkeley Software Distribution (BSD) is a version of Unix operating system.
Clr: Clear
CIDR: Classless Inter-Domain Routing (CIDR) is a method of assigning IP address that improves data routing efficiency on the internet and is used in IPv4 and IPv6.
Control Plane: A Control Plane is a concept in networking that refers to the part of the system responsible for managing and making decisions about where and how data packets are forwarded within a network.
Core: A core may include several lcores or threads if the processor supports Simultaneous Multi-Threading (SMT).
Core Components: A set of libraries provided by DPDK which are used by nearly all applications and upon which other DPDK libraries and drivers depend. For example, EAL, ring, mempool and mbuf.
CPU: Central Processing Unit
CRC: Cyclic Redundancy Check (CRC) is an algorithm that detects errors in data transmission and storage.
Data Plane: In contrast to the control plane, the data plane in a network architecture includes the layers involved when processing and forwarding data packets between communicating endpoints. These layers must be highly optimized to achieve good performance.
DIMM: A Dual In-line Memory Module (DIMM) is a module containing one or several Random Access Memory (RAM) or Dynamic RAM (DRAM) chips on a printed circuit board that connects it directly to the computer motherboard.
Doxygen: Doxygen is a documentation generator used in DPDK to generate the API reference.
DPDK: Data Plane Development Kit
DRAM: Dynamic Random Access Memory (DRAM) is a type of Random Access Memory (RAM) that is used in computers to temporarily store information.
EAL: Environment Abstraction Layer (EAL) is the core DPDK library that provides a generic interface that hides the environment specifics from the applications and libraries.
EAL Thread: An EAL thread is typically a thread that runs packet processing tasks. These threads are often pinned to logical cores (lcores), which helps to ensure that packet processing tasks are executed with minimal interruption and maximal performance by utilizing specific CPU resources dedicated to those tasks. EAL threads can also handle other tasks like managing buffers, queues, and I/O operations.
FIFO: First In First Out (FIFO) is a method for manipulating a data structure where the oldest (first) entry, or “head” of the queue, is processed first.
FPGA: Field Programmable Gate Array (FPGA) i an integrated circuit with a programmable hardware fabric that can be reconfigured to suit different purposes.
FW: Firmware
GbE: Gigabit Ethernet
HW: Hardware
HPET: High Precision Event Timer; a hardware timer that provides a precise time reference on x86 platforms.
Huge Pages: Huge pages are memory page sizes, larger than the default page size, which are supported by the host CPU. These pages are generally megabytes or even gigabytes in size, depending on platform, compared to the default page size on most platforms which is measured in kilobytes, e.g. 4k. Where the operating system provides access to huge page memory, DPDK will take advantage of those huge pages for increased performance.
ID: Identifier
IOCTL: Input/Output Control (IOCTL) is a system call that allows applications to communicate with device drivers to perform specific input/output operations.
I/O: Input/Output
IP: Internet Protocol
IPv4: Internet Protocol version 4
IPv6: Internet Protocol version 6
lcore: A logical execution unit of the processor, sometimes called a hardware thread or EAL thread; also known as logical core.
L1: Layer 1 - Physical Layer is responsible for sending and receiving signals to transmit bits.
L2: Layer 2 - Datalink Layer is responsible for local delivery of frames between nodes. Example: Ethernet.
L3: Layer 3 - Network Layer is responsible for packet routing. Example: IP.
L4: Layer 4 - Transport Layer is responsible for datagram or segment communication. Examples include UDP and TCP.
LAN: Local Area Network
LPM: Longest Prefix Match is an IP routing lookup algorithm where the entry selected is that which matches the longest prefix of the lookup key.
main lcore: The logical core or thread that executes the main() function and that launches tasks on other logical cores used by the application.
mbuf: An mbuf is a data structure used internally to carry messages (mainly network packets). The name is derived from BSD stacks. To understand the concepts of packet buffers or mbuf, refer to TCP/IP Illustrated, Volume 2: The Implementation.
MTU: Maximum Transfer Unit (MTU) is the size of the largest protocol data unit (PDU) that can be communicated in a single network layer transaction. In general, it relates to Ethernet frame size.
NIC: Network Interface Card (NIC) is a hardware component, usually a circuit board or chip, installed on a computer so it can connect to a network.
OOO: Out Of Order (execution of instructions within the CPU pipeline)
NUMA: Non-Uniform Memory Access (NUMA) is a memory design where locality has an impact.
PCI: Peripheral Connect Interface
PHY: An abbreviation for the physical layer of the OSI model.
PIE: Proportional Integral Controller Enhanced (RFC8033)
pktmbuf: An mbuf carrying a network packet.
PMD: A Poll Mode Driver (PMD) is a driver in DPDK, continuously polling as default behavior instead of waiting for a HW interrupt.
PMU: Performance Monitoring Unit
QoS: Quality of Service
RCU: Read-Copy-Update algorithm, an alternative to simple rwlocks. It is a synchronization mechanism that allows multiple threads to read and update shared data structures without using locks.
Rd: Read
RED: Random Early Detection
RSS: Receive Side Scaling
RTE: Run Time Environment. Provides a fast and simple framework for fast packet processing, in a lightweight environment as a Linux* application and using Poll Mode Drivers (PMDs) to increase speed.
Rx: Reception
Socket: For historical reasons, the term “socket” is used in the DPDK to refer to both physical sockets, as well as NUMA nodes. As a general rule, the term should be understood to mean “NUMA node” unless it is clear from context that it is referring to physical CPU sockets.
SLA: Service Level Agreement
srTCM: Single Rate Three Color Marking (srTCM) is a metering technique marking packets either green, yellow, or red.
SRTD: Scheduler Round Trip Delay
SW: Software
Target: In the DPDK, the target is a combination of architecture, machine, executive environment and toolchain. For example: i686-native-linux-gcc.
TCP: Transmission Control Protocol
TC: Traffic Class
TLB: Translation Lookaside Buffer (TLB) is memory cache that stores the recent translations of virtual memory to physical memory to enable faster retrieval.
TLS: Thread Local Storage (TLS) is memory local to a thread. TLS can also relates to the cryptographic protocol.
trTCM: Two Rate Three Color Marking (trTCM) <https://datatracker.ietf.org/doc/html/rfc2698> is a metering technique based on committed and peak rates, and marking packets either green, yellow, or red.
TSC: Time Stamp Counter
Tx: Transmission
TUN/TAP: TUN and TAP are virtual network kernel devices.
VLAN: Virtual Local Area Network
Wr: Write
Worker lcore: Any lcore that is not the main lcore.
WRED: Weighted Random Early Detection (WRED) is a queueing discipline that allows the router to drop random packets to prevent tail drop. This is helpful for TCP/IP connections.
WRR: Weighted Round Robin (WRR) is a scheduling algorithm used to distribute workloads across multiple resources based on assigned weights.