🏙️ MAN (Metropolitan Area Network)

Connect Campuses, Data Centers & Cloud — Fast, Resilient, and Proven

A Metropolitan Area Network (MAN) is the high-speed fabric that stitches together headquarters, campuses, data centers, cloud on-ramps, and edge sites across a city/region.
SolveForce engineers MANs as a system: optical and packet rails (DWDM, wavelengths, Ethernet, IP/MPLS), EVPN/VXLAN campus cores, SD-WAN policy, Zero-Trust edges, and evidence pipelines so every span, class, and change is measurable and auditable.

Related deep dives
• Campus/DC fabric → /networks-and-data-centers • Access/Fiber → /fiber-internet • Optical/DCI → /wavelength • Dark/ Lit → /dark-fiber/lit-fiber
• WAN overlays → /sd-wan • Cloud on-ramps → /direct-connect • Campus LAN → /lan • Wide area → /wan
• Security → /ztna/sase/nac • Edge sites → /edge-data-centers
• Evidence/Ops → /siem-soar/circuit-monitoring • Colo/VDC → /colocation/virtual-data-centers


🎯 Outcomes We Optimize

  • Deterministic latency & throughput — low-microsecond switching, sub-millisecond metro spans for storage, AI fabrics, and real-time apps.
  • Resilience by design — protected rings/meshes, fast reroute, dual laterals/POPs, and SD-WAN brownout steering.
  • Cloud adjacency — private on-ramps (DX/ER/Interconnect) with policy-driven routing and Anycast edges.
  • Security by default — MACsec/L1 crypto where required, segmentation (EVPN/VXLAN), ZTNA for admin access.
  • Evidence on demand — OTDR, light levels, RFC 2544/Y.1564, BGP traces and change diffs to SIEM/SOAR.

🧭 Reference Architecture (metro fabric)

Optical layer (L0/L1)

  • DWDM/ROADM ring or mesh; protected spans with < 50 ms switching; coherent optics for 100/200/400G; optional L1 encryption.
    /wavelength/dark-fiber

Packet transport (L2/L3)

  • Carrier Ethernet: EPL/EVPL/E-LAN/E-Tree for L2 private connectivity.
  • IP/MPLS / Segment Routing (SR-MPLS/SRv6) for L3 VPNs with TE/FRR.
  • EVPN/VXLAN stretching campus fabrics where justified (with failure-domain boundaries).
    /fiber-internet/networks-and-data-centers

Edge & policy

  • SD-WAN across dual underlays (DIA + Metro Ethernet/WL) for application SLOs, packet duplication/FEC for voice/video, Anycast ingress.
    /sd-wan

Cloud & colo interconnect

  • Dual Direct Connect / ExpressRoute / Interconnect POPs; BGP policy/communities; private endpoints in cloud landing zones.
    /direct-connect/colocation

Security & identity

  • MACsec on metro uplinks; ZTNA for admin/console access; NAC 802.1X at campus edges; SASE for web/SaaS.
    /ztna/nac/sase

Evidence & operations


🧰 Service Catalog (what we design & run)

1) Wavelength Services (10/25/40/50/100/200/400G) — protected ROADM rings/mesh, jumbo MTU, fixed FEC, optional L1 crypto.
2) Dark Fiber (IRU/lease) — strand pairs you light; full control over optics, spectrum, and encryption.
3) Carrier EthernetEPL, EVPL, E-LAN, E-Tree; MEF-aligned CoS and OAM.
4) Metro IP/MPLS / SR — L3 VPNs with FRR/TE; Anycast services; DDoS options on Internet edges.
5) Cloud Interconnect — metro cross-connects and NNI to cloud on-ramps with BGP design and route policy.
6) EVPN/VXLAN Campus Extension — any-to-any L2 overlay when needed (with failure domain guardrails).
7) SD-WAN Overlay — per-app SLOs, packet duplication/FEC, breakout strategy, and Anycast ingress for UC/CCaaS.
8) Security — MACsec keys, ZTNA for admin, ACL/SGTs, microseg for crown-jewel VRFs; WAF/Bot at public edges.
9) Ops & Evidence — acceptance suites, monitoring, QBR packs, RCAs, and savings (TEM) where transport is optimized.


📊 Transport & Use-Case Matrix

TechnologySpeedsTypical Latency (metro one-way)Best ForNotes
Wavelength (DWDM)10/25/40/50/100/200/400G≤ 1–2 msDCI, storage (NVMe-oF), AI fabrics, mediaJumbo MTU; coherent optics; L1 crypto optional
Dark FiberYou choose≤ 1–2 msFull control, hyperscale AI, bespoke TERequires optics/ROADM; diversity critical
EPL (L2 P2P)1–100G≤ 1–3 msL2 private line, storage, voice backhaulVLAN-transparent; dedicated path
EVPL (L2 Hub/Spoke)1–10G (typ.)≤ 1–3 msMulti-site spokes, service multiplexingMultiple EVCs per UNI
E-LAN (L2 Any-to-Any)1–100G≤ 1–3 msMulti-campus L2 domainsControl failure domains carefully
IP/MPLS / SR1G–400G≤ 1–5 msL3 VPNs, Anycast servicesFRR/TE; Internet/DDoS edge ready
SD-WAN OverlayPer underlayAdds ≤ 5–10 msApp-aware SLOs, brownout steerPacket dup/FEC for real-time apps

🛡️ Security & Trust (baked in)

  • MACsec/L1 crypto on private transport; TLS/IPsec for targeted flows; DDoS posture on Internet edges.
  • Segmentation with EVPN/VXLAN, VRFs, ACL/SGT; crown-jewel isolation.
  • Admin access via ZTNA, not flat VPNs; device posture checks; PAM JIT for privileged sessions.
  • Policy-as-code and config drift watch to keep the binder == build.
    /ztna/pam/siem-soar

📐 SLO Guardrails (targets you can tune)

DomainKPI / SLO (p95 unless noted)Target (Metro)
Optical spanProtection switch time< 50 ms
Wavelength/EPL one-way latencyMetro≤ 1–2 ms
EVPL/E-LAN L2 lossSustained< 0.05%
IP/MPLS jitterOne-way≤ 1–3 ms
SD-WAN brownout steerPath change≤ 1–3 s
MACsec coverageProtected uplinks= 100% (as scoped)
Cloud on-ramp attachMetro→region edge≤ 2–5 ms
AvailabilityMonthly≥ 99.99% protected core
Evidence pipelineTest/artifact → SIEM≤ 60–120 s
Unapproved changesPolicy gate= 0

Breaches open a case and trigger SOAR (reroute, enable packet-dup, adjust TE, rotate keys, roll back config) with artifacts. → /siem-soar


🔁 Topology Patterns (pick your fit)

PatternProsConsiderationsTypical Use
Ring (ROADM)Fast <50 ms protection, efficient fiberShared risk on adjacent spans3–8 site metro loops
MeshMultiple disjoint paths, high resilienceCost/complexityCore DCI across city
Hub-and-SpokeSimple ops, clear controlHub dependencyBranches ↔ DC/Cloud
Dual-Hub AnycastResilient ingress, easy SD-WANRequires Anycast designUC/CCaaS, Internet edges

📦 QoS Classes (metro quick table)

ClassTrafficMetro Target
EFRTP/voice, critical controlJitter ≤ 1 ms, loss < 0.05%
AF31/41Signaling, prioritized appsJitter ≤ 2–3 ms
BEBulk/backupBest effort; schedule windows

Mark at source, trust at edge, verify end-to-end over MAN and SD-WAN.


🧪 Acceptance Tests & Artifacts (we keep the receipts)

  • Optical — OTDR traces (distance, splice/connector loss), Rx/Tx light levels, BER/FEC counters, ROADM maps.
  • Service activationRFC 2544/Y.1564 throughput, latency, jitter, frame loss; CoS verification.
  • Security — MACsec enablement logs, ZTNA admin admits, ACL/SGT policy tests, WAF/Bot events at Internet edges.
  • Routing — BGP/OSPF/SR policies, Anycast failover tests, FRR timing; cloud on-ramp reachability proofs.
  • SD-WAN — brownout steer and packet-dup/FEC effectiveness; policy diffs.
    All artifacts stream to /siem-soar and bundle into QBR/audit packs.

🧱 Design Notes & Best Practices

  • Diversity matters — separate laterals, providers, bridges/tunnels; request diversity letters and validate with as-builts.
  • Bound your L2 domains — prefer routed access and EVPN/VXLAN boundaries; avoid spanning tree across the metro.
  • Jumbo MTU — align end-to-end for storage/AI movers; test fragmentation behavior.
  • MACsec at edges — especially for PHI/CUI/PCI or multi-tenant routes.
  • Anycast edges — improve ingress for UC/CCaaS and APIs; health-gated withdraw.
  • Policy-as-code — configs in Git with lint/tests; drift watchers; golden builds per device role.

📝 MAN Intake (copy-paste & fill)

  • Sites & addresses (HQ/campuses/DCs/colos/on-ramps) + target RFS
  • Transport preferences (Wavelength speeds, Dark vs Lit, EPL/EVPL/E-LAN, IP/MPLS)
  • Topology goal (ring/mesh/hub-spoke) + diversity requirements (laterals/POPs/providers)
  • Cloud (DX/ER/Interconnect POPs, regions, Private Endpoints only?)
  • QoS & MTU (EF/AF classes, jumbo needs, packet-dup/FEC)
  • Security (MACsec scope, ZTNA admin, ACL/SGT, WAF/DDoS posture)
  • Operations (managed vs co-managed, SIEM destination, change windows)
  • Compliance overlays (HIPAA/PCI/NIST/CJIS/etc.) & artifact retention
  • Budget & timeline (ROM vs build-ready), success metrics (latency, availability, cost)

We’ll return a design-to-quote with carrier options, optical/packet designs, SLO-mapped pricing, acceptance plan, and an evidence pipeline you can reuse in audits and QBRs.
Or jump to /customized-quotes.


📞 Build a MAN That’s Fast, Resilient, and Auditable

From campuses and colos to cloud on-ramps and edge sites, we’ll deliver the metro fabric your business can measure, trust, and prove.