- What the NRS I Certification Actually Is
- Who Issues It and Why That Matters
- The 4A0-100 Exam: Format, Fee, and Logistics
- The Six Exam-Topic Modules
- Why the SR OS CLI Deserves Extra Attention
- Who Should Pursue NRS I
- Career Context and Hiring Signals
- NRS I vs. Other Nokia Credentials
- A Module-Ordered Preparation Sequence
- The 2027 Exam Revision: Plan Around It
- Frequently Asked Questions
- NRS I is Nokia's Network Routing Specialist I certification, earned by passing the single mandatory 4A0-100 exam.
- The 4A0-100 exam has 40 multiple-choice questions and a 90-minute examination time.
- The published exam fee is USD 125; Nokia training prices are separate and not included.
- Six issuer-designated modules guide preparation, from networking basics through VPWS, VPLS, and VPRN services.
What the NRS I Certification Actually Is
NRS I stands for Nokia Network Routing Specialist I. It is the entry-level rung of Nokia's routing certification track, built around the fundamentals of IP networks and the services that run on top of them. If you have seen the acronym elsewhere, set that aside: this article concerns only the Nokia credential and its single required exam, 4A0-100 IP Networks and Services Fundamentals.
The certification validates that a candidate can explain how modern IP networks work and can begin working with Nokia service routers. That means understanding layered TCP/IP models, Ethernet, IPv4 forwarding and addressing, static versus dynamic routing, OSPF and BGP at an introductory level, and the concepts behind VPNs and MPLS transport. It also means being able to place Nokia router products in a network and use the 7750 SR command line to configure basic service components.
For a closer look at naming and terminology, see our explainers on what NRS I stands for and the meaning of NRS I. If you want to start testing yourself right away, the NRS I practice test offers original supplemental questions organized around the same topic areas.
Who Issues It and Why That Matters
The governing body is Nokia, and the credential sits within Nokia's training and certification program for service-router technologies. Because the issuer is a vendor, the exam blends general networking knowledge with vendor-specific product and CLI knowledge. You cannot pass on generic networking theory alone; you need to know how Nokia's service routers, hardware, and operating system present those concepts.
The current Nokia course teaches with the model-driven CLI (MD-CLI), so candidates should be comfortable with that style of operating and configuring SR OS rather than relying on older command conventions from outdated study notes.
The 4A0-100 Exam: Format, Fee, and Logistics
NRS I has one mandatory exam and no mandatory exam prerequisite is listed. That makes the path unusually simple compared with higher-level credentials that require multiple exams or lab components. The details that matter:
| Item | NRS I (4A0-100) |
|---|---|
| Exam title | IP Networks and Services Fundamentals |
| Question format | Multiple choice |
| Number of questions | 40 |
| Examination time | 90 minutes |
| Appointment length | 110 minutes (includes a 20-minute introductory survey) |
| Published exam fee | USD 125 |
| Mandatory exam prerequisite | None listed |
| Additional required exams | None; 4A0-100 is the single mandatory exam |
A common point of confusion is the 110-minute appointment. The extra 20 minutes is an introductory survey, not additional time to answer questions. Your actual working time is 90 minutes for 40 questions, which works out to a little over two minutes per question. That is a comfortable pace for a fundamentals exam, but it still rewards candidates who recognize concepts quickly rather than reasoning from scratch.
Training costs are separate from the exam fee. Course length and purchase price are training facts, not examination facts, so do not confuse them when budgeting. Our NRS I certification cost breakdown separates these categories, and the NRS I requirements guide covers eligibility in more detail.
The Six Exam-Topic Modules
Nokia designates six modules as the candidate exam-topic preparation outline. These are issuer-designated headings and subtopics, not weighted examination domains and not a claim of exhaustive coverage. Nokia directs candidates to the course objectives and modules, so treat the list as your primary map while staying alert that the exam may touch material in neighboring areas. Our complete guide to the six content areas goes deeper on each.
Domain 1: Introduction to Networking and Services
The conceptual foundation. Expect questions on how layered models organize communication and how data moves through those layers.
- Protocol-layer models
- Encapsulating and decapsulating traffic
- Separating control from forwarding
Domain 2: Service Router Components and Command Line Interface
Where the exam becomes distinctly Nokia. You need to know the product family and be able to interact with SR OS.
- Service-router product range
- 7750 SR hardware
- Router boot sequence
- Operating and configuring SR OS
Domain 3: Ethernet
Layer 2 fundamentals, from shared media access to resilient designs.
- Access to shared media
- Hub versus switch behavior
- Link-layer addressing
- VLAN segmentation
- Redundant Ethernet
- Frame structure
Domain 4: The Internet Layer
IPv4 mechanics and how a router decides where a packet goes.
- IPv4 addressing
- Subnetting and summarizing routes
- 7750 SR Layer 3 interfaces
- Forwarding decisions
- Packet-header fields
- Residential and small-business connectivity
Domain 5: IP Routing Protocol Basics
How routers learn and exchange reachability information.
- Static route configuration
- OSPF fundamentals
- BGP introduction
- Internet building blocks
Domain 6: Services Overview
The payoff module: how service providers deliver VPN services over an MPLS core.
- VPN concepts
- MPLS tunnel transport
- Distributing labels with LDP
- Elements of a VPN service
- VPWS, VPLS, and VPRN configuration
Why the SR OS CLI Deserves Extra Attention
Many candidates arrive with solid general networking knowledge and underestimate Domain 2. The module is small in subtopic count but it changes how you read every other topic. When a question about interfaces, static routes, or service configuration appears, it may assume you know how Nokia structures configuration in SR OS and how the MD-CLI organizes it.
Three habits help. First, learn the difference between operational and configuration contexts, since confusing them is a classic source of wrong answers. Second, practice reading configuration snippets and predicting behavior rather than only memorizing commands. Third, connect hardware knowledge, such as the role of the 7750 SR and what happens during the boot sequence, to the software model you configure afterward.
Key Takeaway
Do not treat the Nokia-specific module as an afterthought. Read it early, return to it often, and use it as the lens through which you revisit Ethernet, IPv4, routing, and services.
Who Should Pursue NRS I
NRS I suits several audiences, all of whom benefit from a structured introduction to carrier-grade IP and service concepts:
- Early-career network engineers who want a vendor-backed credential demonstrating fundamentals.
- IT generalists moving toward service-provider or large-enterprise networking.
- Operations and support staff at organizations running Nokia service routers who need to understand what they are monitoring.
- Students and career changers looking for a defined first milestone, since no mandatory exam prerequisite is listed.
Whether it is the right investment for you depends on your goals. Our ROI analysis walks through the trade-offs, and the difficulty guide helps you gauge your starting point.
Career Context and Hiring Signals
Employers most likely to value NRS I are those that operate or support Nokia service-router platforms: telecommunications carriers, internet service providers, managed network service providers, and the integrators and vendors who work with them. For those organizations, a Nokia credential signals that a candidate already speaks the vocabulary of SR OS, MPLS services, and carrier routing.
It is worth being honest about what an entry-level certification does and does not do. It demonstrates foundational knowledge and a commitment to the Nokia ecosystem; it does not substitute for hands-on experience. Role titles that commonly list routing credentials include network engineer, NOC engineer, network operations specialist, and service-provider support engineer. We deliberately avoid quoting salary numbers here because no verified figures exist in our sources; if compensation is your main question, read the salary guide for how to reason about it, and browse NRS I jobs for role context.
NRS I vs. Other Nokia Credentials
Nokia's certification ladder includes higher credentials beyond NRS I. It is important not to blend their requirements. NRS I requires 4A0-100 and nothing more; do not assume that the lab or composite requirements associated with NRS II or SRA apply to it.
| Question | What applies to NRS I |
|---|---|
| How many exams are required? | One: 4A0-100 |
| Is a lab or composite exam required? | No; do not infer lab requirements from other Nokia credentials |
| Is there a mandatory exam prerequisite? | None listed |
| Which exam content is relevant? | The six modules covering fundamentals through services overview |
Treat NRS I as the foundation that later study builds on. The concepts in Domains 4 through 6, particularly routing protocols and VPN services, reappear in greater depth at higher levels.
A Module-Ordered Preparation Sequence
Generic study techniques matter less than ordering your effort around the six modules. Because the exam topics build on each other, a sequence that follows the dependency chain works well. This is one possible plan; adjust the pacing to your background. For fuller strategy, see the NRS I study guide, and keep the cheat sheet handy for last-mile review.
Foundations and the Nokia Platform
- Cover Introduction to Networking and Services: layering, encapsulation, control versus forwarding.
- Begin Service Router Components and CLI: product range, 7750 SR hardware, boot sequence.
Layer 2 and Layer 3
- Work through Ethernet: addressing, VLANs, redundancy, frame structure.
- Start The Internet Layer: IPv4 addressing and subnetting drills.
Forwarding and Routing
- Finish Internet Layer: forwarding decisions, header fields, Layer 3 interfaces.
- Study IP Routing Protocol Basics: static routes, OSPF, BGP introduction.
Services and Integration
- Cover Services Overview: VPN types, MPLS transport, LDP, VPWS/VPLS/VPRN.
- Revisit SR OS CLI and take practice questions across all six modules.
The reasoning is simple: services (Domain 6) rest on MPLS and routing, which rest on IP and Ethernet, which rest on layered-model concepts. Studying out of order forces you to memorize terms you cannot yet place. Interleaving a few CLI sessions throughout makes the Nokia-specific material stick. For structured courses and materials, visit our NRS I training overview.
The 2027 Exam Revision: Plan Around It
This is the single most time-sensitive fact about NRS I. Nokia has announced a revised exam on 2027-03-09, with the exam unavailable from 2027-02-09 through 2027-03-08. The scope described in this article reflects the October 2026 state of the program, so anyone planning to test close to the transition should recheck Nokia's published exam and certification pages first.
In practical terms: if you are studying now, aim to schedule well before the unavailability window begins rather than gambling on the cutover. Candidates who test after the revision should expect the topic outline may differ and should not rely on older notes without verifying them. Our exam dates and scheduling guide covers timing considerations in more detail.
Key Takeaway
Verify the current exam version on Nokia's official pages before you pay, book, or buy study materials. A mismatch between your notes and the live exam is an avoidable risk.
Frequently Asked Questions
NRS I is Nokia Network Routing Specialist I, a Nokia certification validating foundational knowledge of IP networks and services. It is earned by passing the single mandatory 4A0-100 IP Networks and Services Fundamentals exam. For related phrasing, see what NRS I is and our certification overview.
The exam has 40 multiple-choice questions with 90 minutes of examination time. The appointment is 110 minutes because it includes a 20-minute introductory survey, which is not part of the exam clock.
The published exam fee is USD 125. Training is priced separately, so budget for course materials independently if you plan to take the official course.
No mandatory exam prerequisite is listed. You do not need another Nokia exam first, and NRS I does not require the lab or composite elements associated with higher credentials.
The six modules and their 28 subtopics are Nokia's issuer-designated preparation outline, not a weighted blueprint or an exhaustive content list. Study all six rather than concentrating on a guess about weighting.
Yes. Nokia announced a revised exam on 2027-03-09, with the exam unavailable 2027-02-09 through 2027-03-08. Recheck Nokia's official pages before registering if your plans fall near that window.
NRS I rewards candidates who connect general networking theory to Nokia's service-router platform and carry that understanding through to VPN services. Start with the six modules, anchor your practice in the SR OS CLI, and confirm the live exam version before you book. When you are ready to test your understanding, the NRS I Exam Prep practice tests are a useful next step.