Digital coherent optics - Deployment and operation#

Philip Bedard – Cisco

• Why: Coherent pluggables (400ZR/800ZR) are how router-to-router DCI is collapsing the transponder layer — the PM's DC/WAN interconnect interest. Standards-heavy and operational rather than a pitch.
• What: Deployment patterns (unamplified single-channel dark fiber, amplified P2P DWDM, multi-degree ROADM) plus the management story: CMIS AppSel application codes (240 codes in CMIS 5.3+, 128 modes on one 800G-ZR optic), CMIS 0x51h interface-code descriptors that finally expose the optical parameters needed for alien-wave handling, C-CMIS 1.5 (Sept 2026) standardizing coherent performance registers, T-API for the photonic domain, and the OpenConfig operational-mode wart (non-standard numeric IDs like "5003"). Also notes the org convergence: cost savings are driving IP and optical teams to merge.
• How: A working standards matrix across OIF 400ZR/800ZR, OpenZR+ vs 400ZR+, and 100G-ZR (reach/FEC/modulation/power), SFF-8024 host/media IDs, and a model-driven path from pluggable manifest → IP controller → multi-layer controller using IETF/OpenConfig pluggable and impairment-topology drafts.
• Where applicable: Any operator interconnecting routers over dark fiber or DWDM; vendor-presented (Cisco TME) but the content is standards-first. 1.6T coherent standards work is underway — worth tracking for interconnect planning.