100+ Free Nokia QoS Practice Questions

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Which Nokia construct lets multiple SAPs share a common shaper aggregate at a logical level above the queue but below the port?

scheduler-policy parent-child only

vport (virtual port)

filter-list

service-id

to track

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Key Facts: Nokia QoS Exam

Exam Questions

Multiple-choice format

70%

Passing Score

About 28 of 40 correct

90 min

Time Limit

Pearson VUE delivery

$125

Exam Fee

Per attempt (USD)

3 yrs

Validity

Recertify via any current SRC exam

8 FCs

Nokia Forwarding Classes

be, l2, af, l1, h2, ef, h1, nc

The Nokia 4A0-107 Quality of Service exam is a specialist-level Nokia Service Routing Certification (SRC) exam: 40 multiple-choice questions, 90 minutes, 70% passing score, and a $125 USD fee through Pearson VUE. The exam validates skills in DiffServ classification, Nokia's eight Forwarding Classes (be, l2, af, l1, h2, ef, h1, nc), token-bucket policers (srTCM and trTCM), egress shapers, hierarchical scheduling (port → vport → queue-group → queue), WRED slope-policies, the full set of SR OS QoS policy types, and MPLS DiffServ tunneling (Pipe, Short Pipe, Uniform). Pass it as part of the Nokia NRS II track, recertify within 3 years, and pair it with 4A0-103 (MPLS) and 4A0-104 (Services Architecture) for the strongest service-provider profile.

Sample Nokia QoS Practice Questions

Try these sample questions to test your Nokia QoS exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1Which IETF QoS model uses RSVP to reserve per-flow bandwidth state at every router along the path?

A.Best Effort

B.Differentiated Services (DiffServ)

C.Integrated Services (IntServ)

D.MPLS Traffic Engineering

Explanation: IntServ provides QoS on a per-flow basis. Endpoints signal their requirements with RSVP, and every router on the path keeps soft state for each admitted flow. This is the per-flow reservation model defined in RFC 1633.

2Which QoS model defined in RFC 2475 marks packets at the network edge and forwards them as aggregates in the core based on a small codepoint?

A.IntServ

B.DiffServ

C.Best Effort

D.Per-flow Fair Queueing

Explanation: DiffServ (RFC 2475) pushes complex per-flow decisions to the network edge. The edge classifies and marks the DS field with a 6-bit DSCP, and core routers select a Per-Hop Behavior (PHB) for each aggregate. This scales because the core does not maintain per-flow state.

3How many bits are used by the Differentiated Services Code Point (DSCP) inside the IPv4 DS field defined in RFC 2474?

A.3 bits

B.6 bits

C.8 bits

D.16 bits

Explanation: RFC 2474 redefines the IPv4 ToS / IPv6 Traffic Class octet so that the high-order 6 bits carry the DSCP, leaving 2 bits as Currently Unused (later allocated to ECN by RFC 3168). 6 bits give 64 possible codepoints.

4Which Per-Hop Behavior is defined in RFC 3246 and uses the recommended DSCP value 46 (binary 101110) for low-loss, low-delay, low-jitter traffic such as voice?

A.Assured Forwarding (AF)

B.Class Selector (CS)

C.Expedited Forwarding (EF)

D.Default PHB

Explanation: EF (Expedited Forwarding) is the PHB designed to deliver a virtual-leased-line service with low delay, low jitter and low loss. The recommended DSCP is 46 (101110), and it is typically served from a strict-priority queue.

5RFC 2597 defines Assured Forwarding. How many AF classes and how many drop precedences per class does it specify?

A.2 classes and 2 drop precedences

B.3 classes and 3 drop precedences

C.4 classes and 3 drop precedences

D.8 classes and 1 drop precedence

Explanation: RFC 2597 specifies four AF classes (AF1x, AF2x, AF3x, AF4x) with three drop precedences each (low / medium / high), giving twelve codepoints AF11 through AF43. A node MUST give lower drop precedence packets a smaller drop probability under congestion.

6What is the decimal DSCP value of AF31?

A.10

B.18

C.26

D.34

Explanation: AF31 has binary codepoint 011010, which is decimal 26. The pattern is AFxy = 8x + 2y where x is the class (1-4) and y is the drop precedence (1-3): AF31 = 8*3 + 2*1 = 26.

7Which Class Selector codepoint must, per RFC 2474, map to the Default PHB?

A.CS0 (000000)

B.CS1 (001000)

C.CS6 (110000)

D.CS7 (111000)

Explanation: RFC 2474 mandates that codepoint 000000 (CS0) maps to a Default PHB providing best-effort forwarding compatible with the existing Internet practice. CS6 and CS7 historically map to network-control / internetwork-control.

8Which Layer 2 marking field is used to convey QoS in an IEEE 802.1Q tagged Ethernet frame?

A.DSCP

B.MPLS EXP / TC

C.Dot1p (Priority Code Point) — 3 bits

D.DEI bit

Explanation: Inside an 802.1Q tag, the 3-bit Priority Code Point (commonly called Dot1p or 802.1p) carries the Layer 2 class of service, giving 8 possible priority values. The DEI bit (in 802.1ad) is a single drop-eligibility marker, not the class field.

9How many bits are in the EXP (Traffic Class / TC) field of the MPLS shim header, and how many distinct classes does that allow?

A.2 bits, 4 classes

B.3 bits, 8 classes

C.6 bits, 64 classes

D.8 bits, 256 classes

Explanation: The MPLS shim header carries a 3-bit field (originally called EXP, renamed Traffic Class by RFC 5462). Three bits allow 8 distinct traffic classes, which is why DSCP-to-EXP mapping always collapses 64 codepoints to 8 classes at the LSP edge.

10What is the role of the DEI (Drop Eligibility Indicator) bit in IEEE 802.1ad provider bridging?

A.Encodes the Layer 2 class of service

B.Marks frames as eligible for discard during congestion

C.Replaces the VLAN ID for service identification

D.Carries the IP DSCP value across an Ethernet trunk

Explanation: IEEE 802.1ad introduced a single DEI bit so that out-of-profile frames (yellow / out-of-contract) can be marked separately from their PCP class. Forwarders preferentially drop DEI=1 frames during congestion while preserving the original 3-bit PCP for class.

About the Nokia QoS Exam

The Nokia 4A0-107 Quality of Service exam validates the candidate's ability to design, configure, and troubleshoot QoS on Nokia SR OS service-provider networks. The exam covers DiffServ classification with DSCP/Dot1p/MPLS EXP, the IETF Per-Hop Behaviors (EF, AF, CS0-CS7), Nokia's eight Forwarding Classes, token-bucket policers (single-rate two-color, srTCM RFC 2697, trTCM RFC 2698), egress shapers, hierarchical scheduling (H-QoS), WRED slope-policies, SR OS QoS policy types (sap-ingress, sap-egress, network-ingress, network-egress, slope-policy, queue-policy, scheduler-policy), and end-to-end QoS in VPLS/VPRN services with MPLS DiffServ tunneling models (Pipe, Short Pipe, Uniform per RFC 3270).

Assessment

40 multiple-choice questions covering QoS fundamentals (DiffServ, DSCP, Nokia FCs), policing and shaping (srTCM, trTCM, CIR/PIR/CBS), queuing and scheduling (H-QoS, scheduler-policy, WRED), Nokia SR OS QoS policies (sap-ingress/egress, network ingress/egress), and end-to-end QoS in VPLS/VPRN services and MPLS tunneling models

Time Limit

90 minutes

Passing Score

70%

Exam Fee

$125 USD (Nokia / Pearson VUE)

Nokia QoS Exam Content Outline

20%

QoS Fundamentals

DiffServ vs IntServ, RFC 2474 DSCP encoding, classification by IP, transport ports, DSCP, Dot1p, MPLS EXP/TC, DEI; PHBs EF (RFC 3246, DSCP 46), AF (RFC 2597, four classes x three drop precedences), CS0-CS7; Nokia's 8 Forwarding Classes (be, l2, af, l1, h2, ef, h1, nc); profile (in/out) and drop precedence.

25%

Policing and Shaping

Token-bucket policer theory, single-rate two-color, srTCM (RFC 2697 — CIR/CBS/EBS), trTCM (RFC 2698 — CIR/PIR/CBS/PBS), color-blind vs color-aware, Nokia ingress policers per SAP per FC, egress shapers per queue/vport/port, queue MBS/CBS.

25%

Queuing and Scheduling

Strict priority vs WFQ, Nokia H-QoS (port → vport → queue-group → queue), scheduler-policy parent/child, queue-groups (up to 32 queues), MBS/CBS buffer reservation, high-prio-only, slope-policy (WRED min/max threshold + max-prob), tail-drop vs WRED, ECN (RFC 3168).

20%

QoS Policies on Nokia SR OS

sap-ingress (classify + policer), sap-egress (queues + remark), network-ingress (core re-classify), network-egress (mark EXP), slope-policy, queue-policy, scheduler-policy, named queue-groups, default vs custom policies, service-level QoS.

10%

QoS in Services and Networks

Per-SAP QoS in VPLS and VPRN, MPLS DiffServ tunneling (Pipe, Short Pipe, Uniform per RFC 3270), FC-to-EXP marking, end-to-end design across PEs, troubleshooting (show qos sap-ingress, show service id sap stats, show port queue, monitor port queue).

How to Pass the Nokia QoS Exam

What You Need to Know

Passing score: 70%
Assessment: 40 multiple-choice questions covering QoS fundamentals (DiffServ, DSCP, Nokia FCs), policing and shaping (srTCM, trTCM, CIR/PIR/CBS), queuing and scheduling (H-QoS, scheduler-policy, WRED), Nokia SR OS QoS policies (sap-ingress/egress, network ingress/egress), and end-to-end QoS in VPLS/VPRN services and MPLS tunneling models
Time limit: 90 minutes
Exam fee: $125 USD

Keys to Passing

Complete 500+ practice questions
Score 80%+ consistently before scheduling
Focus on highest-weighted sections
Use our AI tutor for tough concepts

Nokia QoS Study Tips from Top Performers

1Memorize the Nokia 8 Forwarding Classes in priority order (be, l2, af, l1, h2, ef, h1, nc) — each maps cleanly to one of the 8 MPLS EXP/TC values, and the exam regularly tests FC-to-DSCP and FC-to-EXP defaults.

2Learn the difference between srTCM (CIR/CBS/EBS, single rate) and trTCM (CIR/PIR/CBS/PBS, two rates) — and remember color-blind vs color-aware mode interpret the incoming color differently.

3Practice walking the H-QoS tree from queue → queue-group → vport → port-level scheduler — and know which level the parent / child / weight bindings happen at.

4Master the four SR OS QoS policy roles: sap-ingress (classify + policer), sap-egress (queues + remark), network-ingress (core re-classify on EXP/DSCP), network-egress (push EXP onto LSP). Most exam questions can be answered just by knowing where each policy lives.

5Memorize RFC 3270 MPLS tunneling: Pipe (LSP TC drives egress, no PHP), Short Pipe (customer DSCP drives egress, PHP allowed), Uniform (LSP TC copied back into customer DSCP at egress).

6Practice the show / monitor commands: 'show qos sap-ingress' (intent), 'show service id <id> sap <port:vlan> stats' (counters), 'show port queue' (snapshot), 'monitor port <port> queue' (live).

Frequently Asked Questions

What is the Nokia 4A0-107 Quality of Service exam?

The Nokia 4A0-107 is a specialist-level exam in Nokia's Service Routing Certification (SRC) program. It validates the candidate's ability to design, configure, and troubleshoot QoS on Nokia SR OS service-provider networks, including DiffServ classification, policing and shaping, hierarchical scheduling, WRED, and end-to-end QoS in VPLS/VPRN services with MPLS DiffServ tunneling.

How many questions are on the Nokia 4A0-107 exam and what is the passing score?

The exam contains 40 multiple-choice questions delivered through Pearson VUE in a 90-minute appointment. The passing score is 70% (about 28 of 40 correct). Questions are weighted across QoS fundamentals, policing and shaping, queuing and scheduling, Nokia SR OS QoS policies, and QoS in services and networks.

How much does the Nokia 4A0-107 exam cost?

The exam fee is $125 USD per attempt. Nokia 4A0-107 is delivered through Pearson VUE testing centers or OnVUE online proctoring. Retake policies and any waiting periods are administered through Pearson VUE — check the current SRC program page for the latest details.

What topics does the Nokia 4A0-107 exam cover?

The exam covers DiffServ vs IntServ, DSCP/Dot1p/MPLS EXP/TC and DEI classification, the EF/AF/CS PHBs, Nokia's eight Forwarding Classes (be, l2, af, l1, h2, ef, h1, nc), token-bucket policers (srTCM and trTCM with CIR/PIR/CBS/PBS), egress shapers, hierarchical scheduling (port → vport → queue-group → queue), slope-policy WRED, all SR OS QoS policy types, per-SAP QoS in VPLS and VPRN, and MPLS DiffServ tunneling (Pipe, Short Pipe, Uniform per RFC 3270).

How long is the Nokia 4A0-107 certification valid?

Like other Nokia SRC component exams, the 4A0-107 credential is valid for 3 years. To remain certified, candidates must pass any current Nokia SRC exam before the expiration date. The 4A0-107 also counts toward the Nokia Network Routing Specialist II (NRS II) credential when combined with the other required exams and the lab.

Do I need experience to take the Nokia 4A0-107 exam?

Nokia does not require formal prerequisites, but the exam assumes solid Nokia SR OS familiarity. Most candidates have already passed NRS I (4A0-100), have hands-on time configuring sap-ingress/egress and scheduler-policy, and have used the SR OS classic CLI. Hands-on labs against vSIM or a Containerlab Nokia image significantly improve readiness.

How does Nokia 4A0-107 fit into the NRS II track?

4A0-107 is one of the SRC component exams that count toward the Nokia Network Routing Specialist II (NRS II) credential. NRS II requires several component exams (such as MPLS 4A0-103 and Services Architecture 4A0-104) plus the NRS II lab. Passing 4A0-107 is the QoS building block of that path.

100+ Free Nokia QoS Practice Questions

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