AI fabric switches carry 800G OSFP112 and 1.6T OSFP224 optics that draw 25 to 40 W per module. However, SONiC powers up inserted modules without considering an overall power budget, aggregate usage, or admission policy.

PowerFence introduces zone-aware optics resource management to SONiC. Operators configure watt budgets per switch and per power or thermal zone, including cold plates on liquid-cooled platforms and power rails or airflow regions on air-cooled platforms. Modules that would oversubscribe their zone remain in Low Power Mode with an explicit reason and are automatically admitted by priority when headroom returns.

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show platform power-budget

Zone Budget(W) Allocated(W) Headroom(W) Ports Fenced
OSFP-LEFT 500.0 480.0 20.0 12 1
OSFP-RIGHT 500.0 360.0 140.0 9 0

Fenced: Ethernet88 (needs 40.0 W, headroom 20.0 W) - low-power mode