An architect receives a business requirement from a CTO that states the RTO for a new system should be 4 hours, and the RPO should be less than 1 hour. Business continuity must also be ensured in…

Asynchronous replication introduces a lag between writes that may exceed the sub-1-hour RPO requirement, and DWDM is typically deployed over metro-scale distances rather than between geographically dispersed disaster-recovery sites.

Asynchronous replication cannot guarantee an RPO under 1 hour due to its inherent write-lag, and CWDM is limited to short-range optical links unsuitable for the geographic separation needed for natural disaster protection.

Metro Ethernet connects sites within the same metropolitan area, meaning a single regional natural disaster could affect both data centers simultaneously and violate the business continuity requirement.

Synchronous replication confirms data is written to both sites before acknowledging each write, guaranteeing near-zero data loss and satisfying an RPO of less than 1 hour. Geographically dispersed data centers ensure a regional natural disaster cannot destroy both sites simultaneously, and MPLS provides the reliable, low-latency WAN transport required to sustain synchronous replication over long distances while meeting the 4-hour RTO.