- 4A0-107 is Nokia's Quality of Service written exam: 40 multiple-choice questions, 90 testing minutes, USD 125 through Pearson VUE.
- It earns Service Routing Architect (SRA) credit, but passing it alone does not award the SRA credential.
- No mandatory prerequisites and no mandatory retake waiting period or attempt limit for the written exam.
- Preparation maps to five modules: Introduction to QoS, Classification, Queues and Policers, Hierarchical Bandwidth Allocation, Marking and Remarking.
What the 4A0-107 Credential Actually Is
The 4A0-107 is Nokia's written exam for Quality of Service in the Service Routing Certification (SRC) program, the track that grew out of the Alcatel-Lucent era and now sits under Nokia. The name is easy to confuse with other credentials that share the same alphanumeric code, so it helps to be precise: everything on this page concerns the Nokia exam on QoS in IP/MPLS service routing networks, and nothing else.
If you are still orienting yourself on terminology, our explainers on what 4A0-107 is and what the code stands for cover the naming background. This article concentrates on what the certification involves and how it fits into a career in carrier and enterprise routing.
Exam Format, Fee, and Booking Mechanics
The logistics are straightforward, and knowing them in advance removes avoidable stress on the day.
| Item | 4A0-107 Detail |
|---|---|
| Delivery | Pearson VUE, proctored online or at a test center |
| Fee | USD 125 |
| Questions | 40 multiple-choice written questions, in English |
| Testing time | 90 minutes |
| Appointment length | 110 minutes, including a 20-minute introductory survey |
| Prerequisites | None mandatory for the exam |
| Retakes | No mandatory waiting period or attempt limit for the written exam |
| Official passing percentage | Not verified in the reviewed public sources |
Two points deserve emphasis. First, the 20-minute introductory survey sits inside the 110-minute appointment but outside your 90 minutes of testing, so do not mistake the appointment length for your working time. Second, because no official passing percentage was verified in public sources, you should treat any single "magic number" you see online with caution. Our pages on the passing score and the pass rate explain what can and cannot be confirmed.
For a fuller view of money and eligibility, see the certification cost breakdown and the requirements guide. For timing and scheduling considerations, the exam dates page is the place to look.
Time budget for 40 questions
Ninety minutes across 40 questions works out to a little over two minutes each. That is generous for recall questions, but QoS items often involve reading a configuration fragment or a traffic scenario and reasoning about what happens to packets. Plan to move quickly on definitional questions so you bank time for the scenario-based ones.
The Five Curriculum Modules, Unpacked
Nokia's public curriculum for the Quality of Service course (3FL30639AAAAZZZZA) lists five headings, and the exam page explicitly directs candidates to that course's objectives and modules. These headings are unweighted preparation modules. Nokia does not publish percentage allocations per module, and the list should not be treated as an exhaustive statement of exam coverage. Use it as your primary map, not as a guarantee of boundaries. A deeper walk-through lives in our exam domains guide.
Module 1: Introduction to QoS
The conceptual foundation. You need to understand why QoS exists on a converged IP network and what problems it addresses.
- The core service-quality concerns: bandwidth, delay, jitter, and loss
- Why best-effort forwarding is insufficient for mixed voice, video, and data traffic
- How QoS is applied per hop along a path, and why consistency across hops matters
Module 2: Traffic Classification
Before traffic can be treated differently, the router must decide which class each packet belongs to.
- Matching on packet header fields and existing markings
- Mapping classified traffic into forwarding classes
- Understanding how classification decisions at ingress drive everything downstream
Module 3: Queues and Policers
Where treatment is actually enforced. Expect scenario questions that ask what happens when a queue fills or a rate limit is exceeded.
- Queue behavior under congestion, including how traffic is serviced and dropped
- Policing versus shaping-style rate control and their different effects on bursts
- The effect of queue parameters on delay and loss for each class
Module 4: Hierarchical Bandwidth Allocation
How capacity is divided among classes, subscribers, and services across multiple levels of scheduling.
- Why a single flat scheduler is not enough for multi-service networks
- How parent and child scheduling levels interact
- Distributing leftover bandwidth when some classes are idle
Module 5: Marking and Remarking
Preserving or changing the QoS signal as traffic crosses network boundaries.
- Writing class information into packet headers for downstream devices
- Remarking at trust boundaries so one operator's markings do not leak into another's policy
- Consistency between internal forwarding class and the marking seen on the wire
Key Takeaway
The five modules form a pipeline: introduce the problem, classify traffic, enforce treatment with queues and policers, divide capacity hierarchically, then mark for the next hop. Study them as one flow of a packet through a router rather than as five isolated lists.
MD-CLI matters
Current course cases and labs use MD-CLI. Even though the written exam is multiple choice and not a live configuration test, you may be asked to interpret configuration snippets. Reading MD-CLI structure fluently, including how policy objects are nested and referenced, will make those questions faster and less error-prone.
Where 4A0-107 Fits in the SRC Program
This exam earns Service Routing Architect (SRA) credit, but passing it alone does not award the SRA. The SRA also involves other written requirements and a separate seven-hour practical lab. Keep the three activities distinct:
- The four-day preparation course: optional training that teaches the material.
- The 90-minute written exam (4A0-107): the proctored multiple-choice test.
- The seven-hour SRA practical lab: a separate hands-on assessment.
If you are weighing whether the investment makes sense for your situation, our ROI analysis walks through the trade-offs, and the salary guide discusses earnings context without relying on invented figures.
Validity and Recertification Rules
SRC certifications are valid for three years, and recertification is available before termination, six months after expiry. Importantly, 4A0-107 is an accepted renewal option for NRS I, NRS II, and SRA. That makes the exam useful in two ways: as a building block toward SRA, and as a renewal vehicle for people who already hold one of those credentials.
A caution on interpretation: these are credential-maintenance rules. They describe how SRC certifications stay current and how this exam can serve renewal. They are not a separately established expiry date attached to the exam credit itself. Keep that distinction in mind when you read summaries that compress the rules.
Who Hires for This Skill Set
QoS knowledge is valued wherever operators carry mixed traffic across IP/MPLS infrastructure and have to honor service-level commitments. The employers and roles most likely to value it include:
- Service providers and carriers running IP/MPLS backbones and aggregation networks that sell differentiated services.
- Enterprises and managed-network providers operating Nokia service routing platforms for wide-area connectivity.
- Systems integrators and consultancies that design, deploy, and tune networks for operators.
- Nokia partners and the vendor ecosystem that support customer deployments.
Typical job titles in this orbit include network engineer, IP/MPLS engineer, network designer, and network architect roles. Our 4A0-107 jobs page goes deeper on role types, and the certification overview provides additional background on how the credential is positioned.
A Module-Ordered Preparation Sequence
Because the modules build on one another, the order in which you study them matters more than the total hours. The sequence below follows the packet's journey through the router and lets later modules reuse earlier vocabulary. Adjust the pacing to your experience; this is a scaffold, not a mandate. For a more detailed plan, see the study guide.
Foundations and Classification
- Work through Introduction to QoS until you can explain the delay, jitter, and loss trade-offs without notes
- Study Traffic Classification so you can trace how a packet gets assigned to a class at ingress
- Read MD-CLI examples of classification policies until the structure feels familiar
Queues and Policers
- Concentrate on queue behavior under congestion and the differences between policing and shaping-style control
- Sketch what happens to each class when a link is oversubscribed
- Answer scenario questions out loud, explaining which packets are dropped and why
Hierarchy, Marking, and Review
- Study Hierarchical Bandwidth Allocation, tracing bandwidth from parent to child scheduling levels
- Cover Marking and Remarking, focusing on trust boundaries
- Finish with mixed-topic practice and a timed run against the 90-minute limit
Queues, policers, and hierarchical allocation typically deserve the most time, since they combine definitions with reasoning about behavior under load. Introduction and marking are lighter on mechanics but still reward careful reading of question wording.
Practice material
Nokia links a public practice document, Practice Exam Questions for Nokia Quality of Service (4A0-107) (copyright 2024, document code CID202017), from its program materials. Use it to get a feel for question style. For additional timed repetition against realistic items, our practice test site offers question sets built for this exam, and the cheat sheet is handy for last-pass review. If you are unsure how demanding the exam is relative to your background, read our assessment of how hard the exam is.
Exam-Day Realities
Whether you test online or at a Pearson VUE center, plan for the 110-minute appointment rather than just the 90 minutes of testing. Arrive or log in early, complete identity checks calmly, and use the introductory survey period to settle in rather than to rush.
- Read the stem twice. QoS questions often hinge on a single qualifier such as ingress versus egress, or policing versus queuing.
- Trace the packet. When a scenario is complex, mentally walk the packet through classification, queueing, and marking in order.
- Flag and return. With a little over two minutes per question, a quick flag-and-move strategy protects your time for harder items.
Because the written exam has no mandatory waiting period or attempt limit, a disappointing result is not the end of the road. Use the experience to see which modules felt weakest, then return to those areas with focused practice at our practice platform.
Frequently Asked Questions
The exam has 40 multiple-choice questions in English, with 90 minutes of testing time inside a 110-minute appointment that includes a 20-minute introductory survey.
The fee is USD 125. The exam is delivered by Pearson VUE, proctored either online or at a test center.
No. The exam earns SRA credit, but passing it alone does not award the SRA. The credential also involves other requirements and a separate seven-hour practical lab.
There are no mandatory exam prerequisites, and the written exam has no mandatory retake waiting period or attempt limit. Training courses are optional preparation guidance, not entry requirements.
Yes. SRC certifications are valid for three years, and 4A0-107 is an accepted renewal option for NRS I, NRS II, and SRA. Recertification is available before termination, six months after expiry.