Nokia QoS flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Forwarding Class (FC)

A label that determines per-hop behavior (PHB) for a packet; Nokia supports eight FCs including NC, EF, AF1-AF4, L1, L2, and BE, each mapped to a queue.

Per-Hop Behavior (PHB)

The externally observable forwarding treatment applied to a packet at each node, defined by DSCP and implemented via queuing, scheduling, and drop policies.

Scheduler Hierarchy

A multi-level scheduling structure where port scheduler controls child schedulers (subscriber/interface) which control queues, enforcing CIR/PIR and priority at each level.

Policer

An ingress rate limiter that measures traffic against committed and peak rates, marking or dropping out-of-profile packets to enforce contracted bandwidth.

Shaper

An egress rate limiter that buffers excess traffic and delays it to conform to a configured rate, smoothing bursts and enforcing PIR.

DSCP

Differentiated Services Code Point, a 6-bit field in the IP header used to classify packets into behavior aggregates for QoS treatment across a network.

MPLS EXP Bits

Three bits in the MPLS shim header used for QoS marking; Nokia routers map EXP to forwarding classes and can re-mark EXP at ingress or egress.

WRED

Weighted Random Early Detection, a queue management mechanism that probabilistically drops packets before queue full, with separate thresholds for in-profile and out-of-profile traffic.

Strict Priority (SP)

A scheduling discipline where higher-priority queues are always served before lower-priority ones, risking starvation of lower-priority traffic if not rate-limited.

Weighted Round Robin (WRR)

A scheduling algorithm that serves queues in proportion to configured weights, providing fair bandwidth sharing among queues of the same priority.

srTCM

Single Rate Three Color Marker, a policer algorithm using committed rate and burst sizes to mark packets green, yellow, or red based on conformance.

trTCM

Two Rate Three Color Marker, a policer algorithm using peak and committed rates to mark packets, typically used for color-aware policing.

SAP Ingress Policy

A QoS policy applied to incoming traffic on a service access point, performing classification, policing, and marking to assign forwarding class and profile.

SAP Egress Policy

A QoS policy applied to outgoing traffic on a service access point, defining queue selection, WRED thresholds, and scheduling behavior.

Subscriber Profile

A configuration object that defines aggregate QoS parameters (rates, scheduler hierarchy) for a subscriber, applied via RADIUS or local provisioning.

CIR

Committed Information Rate, the guaranteed bandwidth for a service or queue that is always available under normal network conditions.

PIR

Peak Information Rate, the maximum bandwidth a service or queue can use when excess capacity is available, often enforced by a shaper.

Hierarchical Scheduling

A scheduling model where parent schedulers enforce aggregate rates before child schedulers distribute bandwidth to individual queues, ensuring fairness and SLA compliance.

Policy Override

A per-SAP configuration that modifies specific QoS parameters (e.g., queue rates or policer rates) without altering the global policy definition.

QoS Flow Identifier (QFI)

In 5G, a scalar value that identifies a QoS flow; Nokia routers map QFI to forwarding classes for transport across backhaul and core.

5G QoS Model

A framework where QoS flows are established with specific QoS parameters (e.g., 5QI) and mapped to DSCP/EXP for transport across the mobile network.

GPON QoS

QoS in Gigabit Passive Optical Networks using 802.1p priority or DSCP classification, with hierarchical scheduling for residential and business services.

Network Slicing

A technique to partition network resources into isolated slices, each with dedicated QoS policies and scheduler resources to meet diverse service requirements.

DSCP to EXP Mapping

The process of translating IP DSCP values to MPLS EXP bits at network ingress, ensuring consistent QoS treatment across MPLS domains.

Fixed Wireless Access QoS

QoS mechanisms in FWA networks that prioritize latency-sensitive traffic and enforce per-subscriber rates via policers and schedulers.

Timing-Sensitive Traffic

Traffic such as synchronization or real-time voice that requires high-priority queuing (NC or EF) to minimize delay and jitter.

TWAMP

Two-Way Active Measurement Protocol, used to measure delay, jitter, and loss between network devices for SLA assurance.

Y.1731

An ITU-T standard for OAM in Ethernet networks, providing performance monitoring functions like frame loss and delay measurement for QoS assurance.

Queue Statistics

Counters that track forwarded and dropped packets per queue, used to monitor congestion and verify QoS behavior.

Policer Statistics

Counters showing packets conforming or exceeding policer rates, helping identify misconfigured rates or traffic bursts.

RFC 2544

A benchmarking methodology for network devices that measures throughput, latency, frame loss, and back-to-back frames per QoS class.

Y.1564

An ITU-T standard for Ethernet service activation testing that validates multiple QoS classes and SLA parameters in a single test.