Operator network design dossier
Metropolitan aggregation & backhaul
An internet service provider is deploying a city-wide network. Four aggregation PoPs connect to two core PoPs.
Illustrated decision
Size an aggregation ring and its core connections to carry the rerouted traffic when one segment fails.
Urban aggregation100 Gbit/s per segment
Assumption for this example
Ring: core A → North → East → core B → South → West → core A.
PoP: point of presence. The diagram shows logical links; physical route diversity still needs to be checked on site.
ArchitectureWhat informs the design
- Network load and growth
- Busy-hour traffic, growth in access connections and the capacity of each segment after a failure.
- Physical diversity
- Fibre routes, shared ducts, building entrances and power feeds: identify shared dependencies.
- Core and interconnections
- Connections to both core PoPs, transit or peering connections, and responsibilities at handover points.
CommissioningWhat supports acceptance
- Disconnect a segment in a controlled test and verify traffic rerouting.
- Measure load, loss and latency on the remaining path, using the agreed acceptance test load.
- Verify services from access connections through to interconnections.
- Restore the link, check stability and record the results.
- Hand over diagrams, configurations, monitoring thresholds and escalation procedures to operations.
An architecture that is sized, deployable and operable.
Capacity · diversity · interconnection · acceptance
Information to gather at the start
Areas to serve, traffic forecasts, available infrastructure, rights of way, accessible PoPs and data centres, planned interconnections and commissioning constraints.
