- The Short Answer: What NRS I Actually Is
- Who Issues It and Where It Sits in Nokia's Training Path
- What the Credential Is Meant to Demonstrate
- The 4A0-100 Exam: Format, Time, and Fee
- The Six Modules Behind the Exam
- Hands-On Skills: MD-CLI and the 7750 SR
- Who Benefits From Holding It
- What NRS I Is Not
- Sequencing Your Preparation Around the Modules
- The 2027 Exam Revision Notice
- Frequently Asked Questions
- NRS I means Nokia Network Routing Specialist I, an entry-level routing and services credential issued by Nokia.
- One mandatory exam earns it: 4A0-100 IP Networks and Services Fundamentals, with 40 multiple-choice questions in 90 minutes.
- The published exam fee is USD 125; Nokia's training prices are separate and not included.
- Six modules, from networking basics to VPN services, form the preparation outline, not a weighted blueprint.
The Short Answer: What NRS I Actually Is
If you have searched for "What Is A NRS I?", here is the direct answer. In the context of this site, NRS I stands for Nokia Network Routing Specialist I. It is a foundation-level certification from Nokia that verifies you understand how IP networks and services work and that you can place Nokia service routers inside those networks. It is the first rung of Nokia's routing certification ladder.
The acronym is shared with unrelated credentials elsewhere in the industry, which is why searches can feel confusing. Everything on this page refers only to the Nokia credential. If you want a broader orientation on the name itself, our companion pieces on what NRS I stands for and the NRS I meaning cover the terminology, and the NRS I certification overview goes into the credential's structure.
Who Issues It and Where It Sits in Nokia's Training Path
The governing body is Nokia, through its networks training and certification program. The credential is tied to a specific course and a specific exam rather than a broad, vendor-neutral body of knowledge. That is a meaningful difference from certifications that draw from many vendors: NRS I teaches networking concepts through the lens of Nokia's service router portfolio and its operating system, SR OS.
NRS I requires one mandatory exam, 4A0-100. Higher Nokia routing credentials exist above it, but they have their own requirements. Do not assume the lab or composite-exam structure of higher levels applies to NRS I. Candidates sometimes read about NRS II or the Service Routing Architect track and import those requirements by mistake. For NRS I, the single multiple-choice exam is the requirement. Our guide to NRS I requirements and eligibility walks through what is and is not needed before you sit for it.
What the Credential Is Meant to Demonstrate
Nokia's learning objectives for the course behind this exam describe what a successful candidate should be able to do. In plain terms, you should be able to:
- Explain layered TCP/IP models and how traffic is encapsulated and decapsulated.
- Describe Ethernet behavior, including shared media access, switching versus hubs, link-layer addressing, VLANs, and redundancy.
- Work with IPv4 addressing, subnetting, route summarization, and forwarding decisions.
- Distinguish static from dynamic routing and describe the fundamentals of OSPF and BGP.
- Explain VPN types and how MPLS provides tunnel transport for them.
- Place Nokia router products in network designs, and use the 7750 SR command line to configure service components.
Notice the balance. Roughly half of this list is general networking knowledge that would apply to any vendor. The other half is Nokia-specific: the product range, the hardware, the boot sequence, the CLI. That mix is what makes the credential distinctive and why generic networking study alone is not enough to prepare.
The 4A0-100 Exam: Format, Time, and Fee
The exam behind NRS I is 4A0-100 IP Networks and Services Fundamentals. Here are the verified logistics:
| Item | Detail |
|---|---|
| Exam code | 4A0-100 |
| Exam title | IP Networks and Services Fundamentals |
| Question format | Multiple choice |
| Number of questions | 40 |
| Exam duration | 90 minutes |
| Appointment length | 110 minutes, including a 20-minute introductory survey |
| Mandatory prerequisite exam | None listed |
| Published exam fee | USD 125 |
Two points deserve emphasis. First, the 110-minute appointment is not the exam duration. The first 20 minutes are an introductory survey, and the timed examination is 90 minutes. Second, the USD 125 figure is the exam fee only. Nokia's training course is priced separately, and its purchase price and length are training facts, not exam facts. For a full breakdown of what budgeting for the whole path involves, see our NRS I certification cost guide.
For scheduling specifics, including how windows and appointments work, refer to NRS I exam dates and scheduling.
The Six Modules Behind the Exam
Nokia organizes preparation around six modules containing 28 subtopics. These are issuer-designated candidate exam topics. They are not weighted exam domains, and they are not an assertion of exhaustive content. Nokia directs candidates to the course objectives and modules, so treat them as your preparation outline rather than a precise blueprint. The full breakdown lives in our NRS I exam domains guide; here is a working summary.
Domain 1: Introduction to Networking and Services
The conceptual foundation for everything that follows.
- Protocol-layer models and how they structure communication
- Encapsulating and decapsulating traffic as it moves between layers
- Separating control from forwarding, a theme that returns in routing and MPLS
Domain 2: Service Router Components and Command Line Interface
The most distinctly Nokia module, and the one generic networking books will not cover.
- The service-router product range and where each platform fits
- 7750 SR hardware components
- The router boot sequence
- Operating and configuring SR OS from the command line
Domain 3: Ethernet
Layer 2 fundamentals, tested at the concept level.
- Access to shared media and why switching replaced it
- Hub versus switch behavior
- Link-layer addressing and frame structure
- VLAN segmentation and redundant Ethernet designs
Domain 4: The Internet Layer
Where most candidates spend the largest share of their effort.
- IPv4 addressing
- Subnetting and summarizing routes
- 7750 SR layer 3 interfaces
- Forwarding decisions and packet-header fields
- Residential and small-business connectivity scenarios
Domain 5: IP Routing Protocol Basics
How routers learn where traffic should go.
- Static route configuration
- OSPF fundamentals
- A BGP introduction
- The Internet's building blocks, meaning how networks interconnect at scale
Domain 6: Services Overview
The module that connects routing to what carriers and enterprises actually sell.
- VPN concepts
- MPLS tunnel transport
- Distributing labels with LDP
- Elements of a VPN service
- VPWS, VPLS, and VPRN configuration
Hands-On Skills: MD-CLI and the 7750 SR
Even though the exam is multiple choice, the course it is based on is practical. The current course uses the model-driven CLI (MD-CLI), so candidates should be comfortable with how SR OS organizes configuration, how you navigate it, and how you commit changes. Questions can describe a configuration scenario and ask you to interpret it, so reading router configuration fluently is a real skill, not a bonus.
The 7750 SR also recurs across modules, appearing in hardware, layer 3 interfaces, and service configuration. Learning the platform once, early, pays off repeatedly. If you can, practice in a lab environment, even a virtual one, rather than relying on reading alone. Our NRS I training overview compares the ways candidates structure that hands-on time.
Who Benefits From Holding It
NRS I fits people whose work touches IP networks and Nokia platforms, or who want to move in that direction. Typical profiles include:
- Telecom and service-provider engineers early in their careers, for whom Nokia routers are part of daily infrastructure.
- Network operations and NOC staff who need a structured foundation in routing, forwarding, and service concepts.
- Systems integrators and pre-sales technical staff who must speak credibly about Nokia products and VPN services.
- Career changers and graduates seeking a vendor-recognized credential that signals practical networking literacy.
Who hires for it? The most direct demand tends to come from organizations that deploy or support Nokia IP and service-routing equipment, including carriers, managed-service providers, and the integrators that serve them. We do not publish invented salary or job-count figures here. For a realistic read on the market, see our write-ups on NRS I jobs and the NRS I salary guide, and for a decision framework, whether the NRS I certification is worth it.
Key Takeaway
NRS I carries the most weight where Nokia hardware is actually deployed. If your target employers run Nokia service routers, the credential is highly relevant. If your path is in a different vendor ecosystem, weigh it more cautiously.
What NRS I Is Not
Clearing up misconceptions saves time and money:
- It is not a lab exam. NRS I is a single multiple-choice test. Do not assume NRS II or Service Routing Architect lab or composite requirements apply.
- It is not a weighted blueprint exam. The six modules are a preparation outline, not percentage-weighted domains.
- It is not a vendor-neutral networking certificate. Concepts are general, but the product context is Nokia's.
- It is not guaranteed by any practice material. Third-party practice content, including ours, is original supplemental study material. It is not issuer-endorsed, it does not reproduce actual exam questions, and it cannot guarantee results.
On difficulty, the exam is introductory in level, but the breadth is real, spanning Ethernet, IP, routing protocols, MPLS, and a vendor CLI. Our analysis of how hard the NRS I exam is unpacks where candidates tend to feel pressure.
Sequencing Your Preparation Around the Modules
Rather than generic study advice, tie your schedule to the structure of the six modules. The logic: later modules build on earlier ones, and the Nokia-specific CLI material benefits from repeated exposure. A sensible pacing might look like this.
Foundations and the Platform
- Work through Introduction to Networking and Services: layering, encapsulation, control versus forwarding
- Begin Service Router Components and CLI early so MD-CLI navigation becomes familiar
Layer 2 and Layer 3
- Cover Ethernet: frames, VLANs, hub versus switch, redundancy
- Start The Internet Layer and drill subnetting until it is automatic
Routing Protocols
- Finish forwarding decisions and header fields
- Study static routes, OSPF fundamentals, and the BGP introduction
Services and Review
- Tackle VPN concepts, MPLS transport, LDP, and VPWS/VPLS/VPRN
- Revisit weak modules with original practice questions
Subnetting and CLI fluency reward repetition, so interleave them across weeks instead of cramming. For a fuller plan, read the NRS I study guide, keep the NRS I cheat sheet nearby for quick review, and use the NRS I practice tests to check yourself under timed conditions.
The 2027 Exam Revision Notice
Timing matters for this credential. Nokia has announced that a revised version of the exam arrives 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, based on Nokia pages reviewed on October 11, 2026.
Always confirm current details directly with Nokia before registering, since fees, scope, and availability can change. When you are ready to test your readiness, take a practice test on the main NRS I site to see which modules need more attention.
Frequently Asked Questions
On this site, NRS I stands for Nokia Network Routing Specialist I. It is Nokia's foundation-level routing and services certification, earned by passing the 4A0-100 IP Networks and Services Fundamentals exam.
One. NRS I requires the single mandatory 4A0-100 exam, a 40-question multiple-choice test lasting 90 minutes. No mandatory prerequisite exam is listed, and you should not assume NRS II or Service Routing Architect lab requirements apply.
The published exam fee is USD 125. Nokia's training course is priced separately, so budget for it as its own line item. Confirm current pricing with Nokia before registering.
No. The appointment lasts 110 minutes, but it includes a 20-minute introductory survey. The timed examination itself is 90 minutes.
No. The six modules and their 28 subtopics are Nokia's issuer-designated preparation outline. They are not a weighted blueprint and are not guaranteed to be exhaustive, so use them as a guide rather than a precise scoring map.
It depends on your career context. It is most valuable if you work with or want to work with Nokia service routers. See our ROI analysis for a structured way to decide.