- NRS I stands for Nokia Network Routing Specialist I, an entry-level routing credential issued by Nokia.
- One mandatory exam earns it: 4A0-100 IP Networks and Services Fundamentals, 40 multiple-choice questions in 90 minutes.
- The published exam fee is USD 125; training prices are separate and should not be confused with it.
- Six modules, 28 subtopics in total, form the preparation outline, but they are not a weighted blueprint.
What the Acronym Actually Means
On this site, NRS I means Nokia Network Routing Specialist I. The "NRS" is Network Routing Specialist, the "I" is the first tier of that specialist track, and the issuer is Nokia. That is the entire expansion, and it is worth stating plainly because the same three letters appear in unrelated contexts elsewhere.
If you landed here searching for a definition, the short version is this: NRS I is a vendor certification that verifies foundational knowledge of IP networking and of how Nokia service routers fit into real networks. It is a routing and services credential, not a general IT certificate. For other phrasings of the same question, see our explainers on what NRS I stands for and what the NRS I certification is.
Why the Label Needs Pinning Down
Acronyms are cheap, and "NRS I" is short enough that it can be read several ways depending on who is talking. A recruiter, a search engine, and a training catalog may each assume something different. Anchoring the term to its issuer prevents wasted effort: if you prepare for the wrong credential, none of your study time transfers.
For Nokia's credential specifically, three anchors settle the question:
- Issuer: Nokia, through its training and certification program.
- Exam code: 4A0-100, titled IP Networks and Services Fundamentals.
- Subject matter: Layered networking, Ethernet, IPv4, basic routing protocols, and an overview of MPLS-based VPN services, with the 7750 SR as the reference router platform.
If a job description, course page, or study resource does not mention Nokia, the 4A0-100 code, or service router concepts, it is probably not describing this credential. A broader overview lives on our what is NRS I page, and the full picture of the certification is in the NRS I certification overview.
Where NRS I Sits in Nokia's Certification Path
The Roman numeral signals sequence. NRS I is the foundational rung, and the issuer's higher routing credentials build on it. That said, the details of those later credentials belong to them, not to this one. NRS I requires 4A0-100 and nothing else: do not substitute NRS II or the Service Routing Architect (SRA) track, and do not assume their lab or composite-exam requirements apply here.
| Question | NRS I Answer |
|---|---|
| Full name | Nokia Network Routing Specialist I |
| Governing body | Nokia |
| Required exam | 4A0-100 IP Networks and Services Fundamentals (single, mandatory) |
| Format | Multiple-choice, 40 questions, 90 minutes |
| Mandatory exam prerequisite | None listed |
| Published exam fee | USD 125 (training is priced separately) |
| Pass threshold / pass rate | Not established in the sources reviewed |
For a deeper look at eligibility, read our guide to NRS I requirements. The absence of a listed exam prerequisite does not mean the material is trivial; it means Nokia lets you attempt the exam without first holding another certification.
The Exam Behind the Name: 4A0-100
Because the credential is awarded on the strength of one exam, understanding that exam is understanding the credential. The 4A0-100 is a multiple-choice test of 40 questions with a 90-minute limit.
Two practical points follow from the format. First, 90 minutes across 40 questions leaves a comfortable per-question budget, so the difficulty comes from knowledge gaps rather than raw time pressure. Second, multiple-choice questions on a fundamentals exam tend to test whether you can distinguish closely related concepts, such as what a switch does versus a hub, or what a routing protocol advertises versus what a label distribution protocol advertises. Our NRS I difficulty guide discusses how that plays out in practice.
Be careful with numbers you may see elsewhere. No current passing score, scored/unscored split, or pass rate is established in the sources reviewed for this article, so treat any figure quoted without a primary source as unverified. We cover what is and is not known on the NRS I passing score and NRS I pass rate pages.
Exam fee versus training cost
The published exam fee is USD 125. The training course that Nokia offers has its own price and its own length, and those are training facts, not examination facts. When budgeting, keep the two line items separate. The full breakdown is in our NRS I certification cost guide.
A transition date to plan around
Nokia has announced a revised exam on 2027-03-09, with the current exam unavailable from 2027-02-09 through 2027-03-08. This article reflects the scope as reviewed in October 2026. If you intend to test near the transition, recheck the issuer's exam page before you register, and see NRS I exam dates for scheduling considerations.
The Six Modules That Define the Credential
Nokia organizes preparation around six modules containing 28 subtopics. These are issuer-designated candidate exam topics. They are not weighted examination domains and not a claim of exhaustive coverage, so there is no percentage attached to any of them. The issuer's own exam page directs candidates to the course objectives and modules as the guide. Our complete domains guide expands each one.
Domain 1: Introduction to Networking and Services
The conceptual groundwork for everything that follows.
- Protocol-layer models
- Encapsulating and decapsulating traffic
- Separating control from forwarding
Domain 2: Service Router Components and Command Line Interface
The hands-on product module, centered on the 7750 SR.
- Service-router product range
- 7750SR hardware
- Router boot sequence
- Operating and configuring SR OS
The current course uses the model-driven CLI (MD-CLI), so practice with that syntax rather than older command styles.
Domain 3: Ethernet
Layer 2 fundamentals.
- Access to shared media
- Hub versus switch behavior
- Link-layer addressing
- VLAN segmentation
- Redundant Ethernet
- Frame structure
Domain 4: The Internet Layer
IPv4 addressing and forwarding logic.
- IPv4 addressing
- Subnetting and summarizing routes
- 7750SR layer 3 interfaces
- Forwarding decisions
- Packet-header fields
- Residential/small-business connectivity
Domain 5: IP Routing Protocol Basics
How routers learn where to send traffic.
- Static route configuration
- OSPF fundamentals
- BGP introduction
- Internet building blocks
Domain 6: Services Overview
The capstone: how a service provider turns routing into sellable services.
- VPN concepts
- MPLS tunnel transport
- Distributing labels with LDP
- Elements of a VPN service
- VPWS/VPLS/VPRN configuration
Key Takeaway
The six modules form a stack: layered models, then the router and its CLI, then Layer 2, then Layer 3, then routing protocols, then services built on top. Each module assumes the one before it, which is why studying them out of order tends to feel harder than it needs to.
The learning objectives in plain terms
Nokia's stated objectives reduce to three abilities. You should be able to explain layered TCP/IP, Ethernet, IP forwarding and addressing, static versus dynamic routing, OSPF and BGP, and the types of VPN along with MPLS transport. You should be able to place Nokia router products within networks. And you should be able to use the 7750 SR CLI to configure service components. Notice the third verb: this is not a pure theory exam, even though it is multiple choice.
What the Credential Signals to Employers
NRS I is vendor-specific, so its value concentrates where Nokia equipment and Nokia-aligned skills matter. The natural audience is anyone working with, or aiming to work with, service provider networks that deploy IP/MPLS: network operations staff, junior network engineers, technical support and field engineers, and people at partners or integrators who handle Nokia platforms.
What it signals is specific and modest in the right way: a candidate who has the layered-networking vocabulary, understands Ethernet and IPv4 forwarding, can reason about basic OSPF and BGP, and has been exposed to how VPN services ride over MPLS. It is a foundation credential, so it is best read as evidence of readiness to learn the platform rather than proof of senior design ability.
We deliberately avoid quoting earnings or hiring statistics here, since none are established in the sources reviewed. For qualitative discussion, see our pages on NRS I jobs, the salary guide, and whether the credential is worth it for your situation.
Sequencing Your Prep by Module
Rather than generic scheduling advice, tie your weeks to the module dependencies. A reasonable order follows the stack described above, with the heaviest conceptual lift placed where the material compounds.
Domains 1 and 3: models and Ethernet
- Get encapsulation and decapsulation straight before anything else
- Contrast hub and switch behavior; learn frame structure and VLAN segmentation
Domain 4: the Internet Layer
- Drill IPv4 addressing and subnetting until it is mechanical
- Work through route summarization and packet-header fields
Domains 2 and 5: router CLI and routing protocols
- Practice MD-CLI navigation and static route configuration
- Learn OSPF fundamentals first, then the BGP introduction
Domain 6: services, then full review
- Connect MPLS transport and LDP to VPWS, VPLS, and VPRN concepts
- Finish with timed mixed-topic sets against a 90-minute limit
Why this order? Domain 6 is the least approachable if you have not internalized forwarding and labels, while subnetting in Domain 4 rewards early, repeated practice. For a fuller plan, see the NRS I study guide, and keep the NRS I cheat sheet handy for last-pass review. If you want structured courseware context, our NRS I training page explains how training relates to the exam.
When you are ready to test yourself, original practice questions on the main practice test site are written as supplemental study material. They are not actual exam questions, are not issuer-endorsed, and cannot guarantee results; use them to find weak modules, then return to the course objectives for the authoritative scope.
Frequently Asked Questions
NRS I stands for Nokia Network Routing Specialist I. It is Nokia's entry-level routing certification, earned by passing the 4A0-100 IP Networks and Services Fundamentals exam. See also what NRS I means in other contexts of the term.
One. The single mandatory exam is 4A0-100. It has 40 multiple-choice questions and a 90-minute limit. No other exam, and no lab, is part of the NRS I requirement.
No. The six modules and their 28 subtopics are an issuer-designated preparation outline, not a weighted blueprint and not an assertion of exhaustive coverage. Prepare across all six rather than guessing at percentages.
No mandatory exam prerequisite is listed. Familiarity with basic networking helps, but you do not need to hold another certification first.
Nokia has announced a revised exam on 2027-03-09, with the current exam unavailable from 2027-02-09 through 2027-03-08. Verify the current version on Nokia's exam page before registering.
In short, "NRS I" has one meaning here: Nokia Network Routing Specialist I, a foundation credential built on a single 40-question exam and six modules that run from layered models to MPLS-based VPN services. Treat the issuer's course objectives as your source of truth, and use the resources linked above to fill in cost, difficulty, and scheduling details.