Metropolitan Area Networks - Learning Module

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Campus Networks

The Campus as Metropolitan Microcosm

Campus networks occupy a unique position in the network hierarchy. They span geographic areas larger than traditional LANs—often covering several square miles with dozens of buildings—yet remain under single organizational control. Universities, hospitals, corporate headquarters, research parks, and military installations all deploy campus networks that function as self-contained metropolitan networks.

These environments combine the complexity of city-wide networks with the control of enterprise LANs. A large university campus might connect 200+ buildings across 2,000 acres, supporting 50,000 daily users with bandwidth demands rivaling small cities. Yet this infrastructure answers to a single IT organization that can implement unified standards and policies.

This page explores the distinctive characteristics, architecture patterns, and operational considerations for campus-scale metropolitan networks.

What You Will Learn

You'll understand campus network architectures, the unique requirements of academic, healthcare, and corporate environments, fiber backbone design, building distribution, wireless integration, and the operational challenges of supporting diverse and demanding user communities.

Campus Network Characteristics

Campus networks exhibit distinct characteristics that differentiate them from both building-scale LANs and city-scale MANs. Understanding these characteristics is essential for appropriate design.

Defining Attributes of Campus Networks:

Core Campus Network Characteristics

•Contiguous Geography — Buildings typically clustered within walkable distance; fiber runs measured in hundreds of meters to few kilometers; campus perimeter often defines network boundary
•Single Administrative Domain — One IT organization controls all infrastructure; unified policies, standards, and purchasing; simplified security and management compared to multi-organization MANs
•High Density — Thousands of users per building in some cases; density creates unique capacity and interference challenges especially for wireless
•Diverse User Populations — Students, faculty, staff, guests, contractors, vendors all require different access levels and services on shared infrastructure
•Owned Infrastructure — Organization typically owns buildings, conduit, fiber, and equipment; control enables optimization but requires capital investment
•Predictable Traffic Patterns — Academic schedules, shift changes, event calendars create somewhat predictable demand patterns enabling capacity planning

Campus Types and Network Characteristics
Campus Type	Typical Scale	User Density	Critical Applications	Key Challenges
University	100-500 buildings	20,000-80,000 users	Research, LMS, library, housing	BYOD diversity, research needs, housing
Hospital/Healthcare	10-50 buildings	5,000-20,000 users	EHR, PACS, telemedicine	HIPAA, life safety, 24/7 operations
Corporate HQ	20-100 buildings	10,000-50,000 users	ERP, collaboration, security	Guest access, IoT, executive security
Research Park	50-200 buildings	10,000-30,000 tenants	High-speed data, lab systems	Multi-tenant, diverse requirements
Military/Government	50-500 buildings	Varies widely	Classified, command, logistics	Security classification, redundancy

Campus vs. MAN vs. LAN Comparison:

Dimension	Building LAN	Campus Network	City-Wide MAN
Geography	Single building	Multiple buildings (1-10 km²)	City/region (10-100+ km²)
Ownership	Single owner	Single owner	Varies (owned/carrier/hybrid)
Control	Complete	Complete	Complete to partial
User Count	100-5,000	1,000-100,000	10,000-1,000,000+
Fiber Distances	<500m	100m-5km	5-50+ km
Regulatory Burden	Minimal	Moderate	Significant
Construction	Interior/minor	Campus grounds	Public ROW

Campus networks combine the control advantages of LANs with the geographic scale requiring MAN-like backbone infrastructure.

The Extended Campus

Many organizations operate satellite facilities beyond the main campus—research stations, off-campus student housing, affiliated clinics. These create hybrid requirements: campus-like control expectations with MAN-like distances, often requiring carrier services or dedicated fiber construction for connection.

Campus Network Architecture

Campus networks follow well-established hierarchical architecture patterns that provide scalability, manageability, and resilience. The classic three-tier enterprise architecture remains the foundation, though two-tier collapsed designs increasingly serve smaller or newer deployments.

Three-Tier Campus Architecture:

Converting Mermaid diagram...

Layer Responsibilities:

Core Layer:

High-speed backbone connecting all distribution blocks
Aggregation point for data center, WAN, and Internet connectivity
Designed for maximum throughput and availability
Minimal policy—fast forwarding is primary function
Typical bandwidth: 40-400 Gbps aggregate
Technologies: L3 routing (OSPF/IS-IS), VXLAN/EVPN fabric

Distribution Layer:

Aggregates access switches within a building or building group
Implements routing, policy, and QoS at building boundary
Provides redundant uplinks to core
May implement inter-VLAN routing
Typical bandwidth: 10-40 Gbps to core, 1-10 Gbps to access
Technologies: L3 routing, VLANs, QoS marking/queuing

Access Layer:

Connects end devices (computers, phones, APs, printers)
Provides port-level security (802.1X, MAC filtering)
Powers devices (PoE/PoE+/PoE++)
Typical bandwidth: 1 Gbps to devices, 10-25 Gbps uplinks
Technologies: L2 switching, PoE, 802.1X, VLAN assignment

Collapsed Core/Two-Tier Architecture:

Smaller campuses may combine core and distribution functions:

When Two-Tier Works:

Campus with fewer than ~20 access closets
Limited growth expectations
Budget constraints requiring equipment reduction
Simplified environment with straightforward policies

Two-Tier Structure:

Collapsed core switches provide both backbone and distribution functions
Access switches connect directly to collapsed core
Reduces equipment and complexity
May limit scalability and policy flexibility

Modern Fabric Architectures:

SD-Access, VXLAN/EVPN fabrics, and similar technologies are reshaping campus architecture:

Fabric Benefits:

Simplified provisioning through automation
Consistent policy enforcement campus-wide
Macro-segmentation without complex VLAN engineering
Easier incorporation of wireless as first-class citizen
Improved visibility and analytics

Fabric Considerations:

Requires compatible equipment across campus
Operational staff training investment
Vendor-specific implementations limit interoperability
Transition from traditional architecture requires planning

Designing for Decades

Campus buildings last 50+ years. The fiber infrastructure should last as long. Even though equipment changes every 5-10 years, the physical plant is nearly permanent. Design conduit pathways, fiber counts, and building entrance facilities for long-term scalability, not just current needs.

Campus Fiber Backbone Design

The fiber optic backbone is the physical foundation of campus networks, representing long-term infrastructure investment that outlasts multiple generations of active equipment. Thoughtful fiber design enables decades of network evolution.

Fiber Planning Principles:

Campus Fiber Design Principles

•Overprovisioning — Install 2-4x the fiber strands currently needed; labor/conduit costs dominate, additional fiber is marginal; future demand always exceeds projections
•Path Diversity — Create at least two geographically separate paths between critical buildings; avoid single conduit runs that create single points of failure
•Ring Topology — Campus fiber rings enable self-healing connectivity; buildings access ring at two points for redundancy
•Future Building Sites — Extend conduit to planned construction sites; add building stubs during initial construction when possible
•Fiber Documentation — Maintain accurate splice records, route maps, and strand assignments; essential for troubleshooting and capacity planning

Recommended Fiber Strand Counts by Application
Application	Minimum Strands	Recommended	Fiber Type	Rationale
Building backbone	12 strands	48-96 strands	Single-mode	Per-floor pairs, future growth, diverse services
Data center interconnect	48 strands	144-288 strands	Single-mode	Multiple parallel 400G paths, storage, backup
Distribution aggregation	24 strands	48-144 strands	Single-mode	Multiple distribution uplinks, redundancy
Intra-building (risers)	12 strands	24-48 strands	Single-mode or OM4	Floor-to-floor connections, flexibility
Wireless/IoT fronthaul	6 strands	12-24 strands	Single-mode	AP aggregation, sensor connectivity

Conduit and Pathway Design:

Underground Conduit Systems:

Rigid Conduit (PVC/HDPE): Primary method for campus distribution; 4" typical for backbone, 2" for building laterals
Innerduct: Subdivides larger conduit for organized cable pulls; 1.25" typical fabric innerduct
Pulling Vaults/Handholes: Located at intersections, changes of direction; enable segmented pulls
Manhole Vaults: Larger access points for major junction areas; splice locations

Recommended Conduit Quantities:

Backbone routes: 4-8 × 4" conduits (or equivalent microduct)
Building laterals: 2-4 × 4" conduits minimum
Always include empty spares: At least 25-50% spare conduit capacity

Aerial vs. Underground:

Factor	Underground	Aerial
Protection	Superior (weather, damage)	Vulnerable (storms, vehicles)
Cost	Higher initial	Lower initial
Aesthetics	Invisible	Visible
Maintenance	Harder to access	Easier to access
Lifespan	50+ years	20-30 years
Campus Standard	Preferred	Sometimes used for quick additions

Fiber Termination:

Building Entrance Facilities (BEF):

Dedicated room or area for fiber termination
Fiber patch panels with organized cable management
Climate control to prevent condensation
Physical security (locked room/cabinet)
Documented patch records

Cross-Connect vs. Interconnect:

Cross-connect: Patch cords between termination panels; most flexible
Interconnect: Direct termination to active equipment; reduces patch cord mess
Best practice: Cross-connect at distribution, may interconnect at access

The Documentation Imperative

Undocumented fiber becomes 'dark' fiber in the worst sense—unusable because its routes and assignments are unknown. Maintain fiber management databases, splice records, and strand allocation logs. Update documentation with every change. This investment pays dividends during every repair, capacity addition, or audit.

University Campus Networks

University networks face unique challenges arising from academic culture, diverse user populations, research requirements, and the residential component of campus life. These networks often pioneer new technologies and must accommodate extraordinary demands.

University Network Stakeholders:

University User Populations and Requirements
User Group	Device Types	Bandwidth Needs	Special Requirements
Undergraduate Students	Laptops, phones, tablets, gaming	100 Mbps - 1 Gbps	BYOD diversity, social/streaming, housing
Graduate Students	Research workstations, personal devices	1-10+ Gbps (research)	Lab access, data transfer, remote access
Faculty	Office systems, research equipment	1-100+ Gbps (varies)	Research data, collaborations, home access
Staff	Office workstations, mobile	100 Mbps - 1 Gbps	ERP, email, departmental systems
Campus Visitors	Personal devices	10-100 Mbps	Guest authentication, internet access
Research Instruments	Specialized systems	10-400 Gbps	Science DMZ, dedicated paths, lossless

Distinctive University Network Requirements:

Residential Networking:

Dormitories/residence halls create housing-grade demands
1-4 devices per resident; thousands per building
Always-on lifestyle: peak usage midnight-2 AM common
Streaming video dominates bandwidth consumption
Guest access for family/friends during visits
Design: 1 Gbps per room, 100+ Gbps per building common

Research Computing:

Research data ranges from modest to extreme (petabyte-scale)
External collaborations: Internet2, CERN, national labs
Science DMZ: Bypass security controls for trusted high-speed transfers
Lossless fabric requirements for some HPC workloads
Grant-funded equipment may have specific network requirements

Academic Freedom Considerations:

Generally permissive filtering approach
Must support diverse research and academic inquiry
Balancing security with academic openness
Copyright/DMCA compliance requirements
International student population with global access patterns

University Network Best Practices

•Federated Identity (eduroam) — Support eduroam for visiting academics; seamless roaming between institutions worldwide enabled by RADIUS federation
•Science DMZ Architecture — Dedicated high-performance paths for research data; perfSONAR monitoring; friction-free for approved research workflows
•Student Network Segmentation — Separate residential/academic traffic; protect administrative systems from student network exposure
•Event Capacity Planning — Move-in day, graduation, major athletics create massive surge demands; wireless density must accommodate
•E-learning Infrastructure — LMS, lecture capture, online proctoring require reliable, low-latency connectivity; increasingly critical post-pandemic
•Academic Computing Labs — Managed computer labs still relevant; thick or thin client deployment for curriculum software

Student as Customer

Today's students compare campus networks to consumer-grade experiences. They expect Wi-Fi that works everywhere instantly, matching or exceeding their home ISP speeds. Meeting these expectations requires substantial investment in wireless density, backhaul capacity, and operational excellence. Poor network quality affects student satisfaction and recruitment.

Healthcare Campus Networks

Healthcare campus networks must support life-critical applications, stringent regulatory requirements, and 24/7/365 operations. The network is literally part of patient care infrastructure, and failures can have life-safety consequences.

Healthcare Network Requirements:

Critical Healthcare Network Requirements

•Life-Critical Availability — Network failures can impact patient care; dialysis machines, ventilators, and infusion pumps increasingly network-connected; 99.999%+ availability target
•HIPAA Compliance — Protected Health Information (PHI) requires encryption in transit, access controls, audit logging; network design must support compliance
•Medical Device Integration — Thousands of devices: monitors, imaging equipment, infusion pumps; many legacy devices with poor security; IoMT (Internet of Medical Things) challenges
•High-Bandwidth Imaging — PACS (Picture Archiving and Communication System) moves large imaging studies; single CT scan can exceed 1 GB; radiology workflows bandwidth-intensive
•Real-Time Telemetry — Patient monitors transmit continuous data; requires consistent low latency; alarm systems depend on reliable delivery
•Guest and Patient Access — Patients expect connectivity during stays; guest network must be isolated from clinical systems; entertainment services increasingly expected

Healthcare Network Segmentation:

Healthcare networks require particularly rigorous segmentation to protect clinical operations and patient data:

Clinical Network:

EHR (Electronic Health Record) systems
Clinical workstations and mobile devices
Medical devices requiring clinical data access
Protected by advanced threat detection
HIPAA-compliant controls throughout

Medical Device Network (Biomedical):

Legacy devices often Windows XP or proprietary OS
Cannot be patched or updated in many cases
Isolated from general network access
Vendor remote access tightly controlled
Network-based security compensates for device vulnerabilities

Building/Facility Systems:

HVAC, elevators, building automation
Physical security cameras and access control
Separated from clinical networks
Often managed by facilities department

Guest/Patient Network:

Internet access for patients and visitors
Completely isolated from clinical systems
May include entertainment (streaming, TV)
Limited to prevent abuse

Administrative Network:

Finance, HR, non-clinical operations
Standard enterprise security controls
Separated from clinical where practical

Healthcare Application Network Requirements
Application	Bandwidth	Latency	Availability	Security Priority
EHR Access	5-50 Mbps/user	<100 ms	99.99%	Highest (PHI)
PACS/Imaging	100 Mbps - 10 Gbps	<50 ms preferred	99.99%	High (diagnostic)
Patient Monitors	100 Kbps - 1 Mbps	<20 ms critical	99.999%	Life-critical
Voice (clinical)	100 Kbps/call	<150 ms	99.99%	High (clinical coordination)
Telehealth	5-25 Mbps/session	<150 ms	99.9%	High (PHI in video)
Guest Internet	10-100 Mbps shared	Best effort	99%	Isolated

The Biomedical Device Challenge

Medical devices often have 10-15 year lifecycles with minimal security updates. Devices may require legacy protocols (Telnet, unencrypted connections) that violate modern security policies. Network architecture must contain risk through segmentation, monitoring, and compensating controls rather than relying on device security.

Corporate Campus Networks

Corporate headquarters and business park campuses support enterprise operations with requirements emphasizing security, compliance, productivity, and the evolving hybrid work paradigm. These networks serve as the flagship infrastructure that business depends on.

Corporate Campus Network Drivers:

Corporate Network Priorities

•Security First — Corporate IP, financial data, and business communications require protection; zero-trust principles increasingly mandated; DLP and threat detection essential
•Unified Communications — Voice, video, messaging integrated; Microsoft Teams, Zoom, WebEx demanding network quality; executive expectations for flawless conferencing
•Productivity Applications — ERP, CRM, productivity suites central to operations; SaaS application performance critical; cloud connectivity optimization
•Guest and Contractor Management — Visitors need internet access; contractors may need limited internal access; onboarding/offboarding efficiency matters
•IoT and Smart Building — Conference room tech, environmental sensors, building systems; growing device population with security implications
•Work From Anywhere Support — VPN/ZTNA capacity for remote workers; campus network may be hub for distributed workforce

Corporate Network Architecture Trends:

SD-Access and Identity-Based Policy:

Users authenticated and authorized based on identity, not port
Policy follows user across wired and wireless
Simplified onboarding for new devices
Visibility into who/what is on the network
Micro-segmentation without VLAN complexity

Cloud Connectivity Optimization:

Direct internet access from campus (vs. backhauling to data center)
SD-WAN integration for branch and campus
SaaS application performance optimization
Split-tunnel VPN for remote workers
CASB integration for cloud security

Wireless-First Design:

Many employees primarily wireless connected
Desk phones declining; softphones and mobile dominant
Conference rooms require robust wireless for collaboration
Wired ports still needed for performance and legacy devices
Wi-Fi 6/6E becoming standard deployment

Corporate Workspace Connectivity Standards
Space Type	Wired Ports	Wireless Coverage	Special Requirements
Executive Office	2-4 ports	HD coverage	Video conferencing, guest access
Open Office Workstation	1-2 ports	HD coverage	VoIP, hot-desking support
Conference Room (small)	4-8 ports	Dedicated AP	Video conferencing, screen sharing
Conference Room (large)	8-16 ports	2+ APs	Multiple simultaneous video feeds
Lobby/Reception	2-4 ports	Guest coverage	Visitor registration, digital signage
Cafeteria/Common Area	Minimal	High density	BYOD, streaming tolerance
Data Center/Server	High density	Minimal	iLO/management, rack density

Executive and Sensitive Areas:

Corporate campuses often include areas requiring enhanced security:

Executive floors: Additional access controls, enhanced monitoring
Board rooms: Counter-surveillance considerations, isolated networks
Legal/HR areas: Sensitive data handling, DLP enforcement
Financial operations: PCI compliance if card processing; SOX controls
R&D facilities: Trade secret protection, access restrictions

Network design for these areas may include:

Physical isolation from general network segments
Enhanced logging and monitoring
Dedicated equipment inspected for tampering
Wireless carefully controlled or disabled
Guest access prohibited or heavily restricted

The Hybrid Work Evolution

Post-pandemic, corporate campuses must serve a hybrid workforce—some employees always present, some always remote, many splitting time. Network design should support this flexibility: easy temporary workspace setup, robust remote access, and capacity planning that accounts for unpredictable on-site populations.

Campus Wireless Networks

Wireless networking has become the primary access method for most campus users. Designing and operating wireless at campus scale requires attention to density, interference, roaming, and the unique characteristics of each environment type.

Campus Wireless Design Principles:

Wireless Design Fundamentals

•Capacity-Based Design — Design for device density, not just coverage; lecture halls may need one AP per 30-50 users; open offices similar density
•5 GHz/6 GHz Priority — Steer devices to less congested bands; 2.4 GHz for IoT and legacy only; Wi-Fi 6E enables 6 GHz for high-performance
•Channel Planning — Minimize co-channel interference through careful assignment; automated radio resource management (RRM) helps but needs tuning
•Seamless Roaming — 802.11r (Fast BSS Transition) for voice/video continuity; consistent SSID deployment campus-wide; controller-based or cloud-managed
•Wired Backhaul — APs require wired connectivity; 1 Gbps minimum, 2.5/5 Gbps for Wi-Fi 6/6E; fiber to closets with PoE switches
•Location Services — Wi-Fi can enable indoor location; wayfinding, asset tracking, analytics; additional infrastructure may be required

Campus Wireless Density Guidelines
Environment	Users per AP	AP Spacing	Special Considerations
Lecture Hall (seated)	30-50	1 AP per 1,500 sq ft	Fixed seating, predictable density
Library/Study Area	20-40	1 AP per 2,000 sq ft	Mixed seating, laptop-heavy
Cafeteria/Commons	40-60	1 AP per 1,500 sq ft	Meal time peaks, casual browsing
Office (open plan)	20-30	1 AP per 2,500 sq ft	Workday usage, video calls
Office (private)	Per office or 2-3	Coverage based	Wall attenuation varies
Residence Hall	8-15	1 AP per 4-6 rooms	24/7 usage, streaming heavy
Stadium/Arena	100-250	Distributed antenna systems	Massive simultaneous usage
Outdoor/Quad	Varies widely	Directional/mesh	Weather, wide coverage

Authentication and Onboarding:

802.1X/EAP Authentication:

Preferred for campus-owned and long-term devices
EAP-TLS (certificates) most secure
EAP-PEAP/MSCHAPv2 common with username/password
Integrates with Active Directory, LDAP, RADIUS
Device-specific policies based on authentication result

eduroam (Education Roaming):

Federated authentication for academic institutions
Visitors from member institutions authenticate against home institution
Campus users authenticate at visited institutions
Requires proper RADIUS proxy configuration
Growing to include K-12 and research organizations

Captive Portal (Guest Access):

Self-registration or sponsor-approved guest access
Time-limited credentials
Isolated VLAN with internet-only access
May require acknowledgment of acceptable use policy
SMS or email validation for accountability

BYOD Onboarding:

Self-service certificate provisioning
MDM enrollment for managed devices
Device profiling identifies device type
Automated VLAN/policy assignment

Wi-Fi 6 (802.11ax) and Wi-Fi 6E Campus Adoption:

Wi-Fi 6 Benefits:

OFDMA: Better efficiency in high-density environments
BSS Coloring: Improved interference handling
Target Wake Time: Battery life for IoT devices
Higher throughput: 9.6 Gbps theoretical maximum

Wi-Fi 6E (6 GHz Band):

1,200 MHz of new spectrum (more than 2.4 + 5 GHz combined)
Greenfield band—no legacy devices to accommodate
Ideal for high-performance, controlled environments
Shorter range requires more APs for coverage
Client adoption growing but not yet universal

Deployment Considerations:

Upgrade APs progressively; Wi-Fi 6/6E APs serve older clients too
Prioritize high-density areas first
Wired infrastructure may need upgrades (2.5G/5G interfaces)
Budget for increased AP count as 6E requires denser deployment

The Continuous Evolution

Wireless technology evolves rapidly—Wi-Fi 7 (802.11be) is already emerging with multi-link operation and 320 MHz channels. Campus networks should budget for ongoing wireless refresh cycles (typically 5-7 year AP replacement) and design physical infrastructure (cabling, outlets, pathways) to accommodate future AP densities.

Summary: Campus Networks

Campus networks represent sophisticated metropolitan-scale infrastructure under unified organizational control. Success requires understanding both the architectural fundamentals and the unique requirements of each campus environment.

Key Takeaways

•Campus networks bridge LAN and MAN — Geographic scale of MANs with control benefits of LANs; unique optimization opportunities and challenges.
•Hierarchical architecture scales — Three-tier (core/distribution/access) remains foundational; two-tier and fabric variants suit specific contexts.
•Fiber infrastructure is permanent — Design backbone for decades of evolution; overprovision strands, document meticulously, maintain path diversity.
•Universities demand diversity — Research, residential, academic, and administrative functions create extremely varied requirements on shared infrastructure.
•Healthcare prioritizes life-safety — Network is part of care delivery; segmentation, legacy device handling, and extreme availability are paramount.
•Corporate campuses emphasize security — Zero-trust, unified communications, and hybrid work support define modern corporate network design.
•Wireless is primary access — Capacity-based design, proper authentication, and continuous technology evolution are essential for campus wireless.

What's Next:

The final page of this module examines MAN Applications, exploring real-world use cases across industries and how metropolitan networks enable critical business, government, and societal functions.

Page Complete

You now understand campus network architecture, the specialized requirements of academic, healthcare, and corporate environments, fiber backbone design, and wireless deployment strategies. This knowledge prepares you to design, evaluate, or operate campus-scale metropolitan networks.