- IN publishers Up, where a feed enters
- OUT receivers Up, where it is delivered
- Reach, not the route the packets take
Where feeds enter DoubleZero, and how far they reach
Each glowing dot is a metro where a feed’s publishers attach to DoubleZero and report BGP Up. Each ring is a metro where its receivers attach. A reach line joins every ingress metro to every receiver metro in the same family. Multicast carries every publisher’s packets to every subscriber, so each line is a real reach. The ledger holds no per-feed path, though, so a line is a great circle lifted off the surface, not a fiber route.
Farthest receiver is the receiver metro that sits farthest from its nearest ingress metro, measured along the great circle. The time after it is how long light in fiber needs over that distance, about 204 km per millisecond. Real paths are longer, so read it as a lower bound. It doesn’t mean that receiver gets its data from that ingress. The ledger doesn’t record which publisher wins.
Locations are DoubleZero attachment metros, not publisher hosts or matching engines. Counts are accounts reporting Up in the snapshot. The Atlas covers the method, the limits and the full tables.