Linear Pluggable Optics (LPO) enables low-latency, power-efficient optical connections in switches, with DSPLPO indicating DSP-free interoperability between modules.

What is LPO?

Linear Pluggable Optics (LPO) is an optical transceiver technology designed to reduce power consumption and latency by eliminating the Digital Signal Processor (DSP) typically used in pluggable modules . Instead of relying on DSPs for signal equalization and regeneration, LPO systems distribute these functions across the switch ASIC, driver IC, and high-linearity Transimpedance Amplifiers (TIAs). This approach maintains a pluggable form factor, allowing hot swapping, easy servicing, and interoperability between modules .

LPO in Switch Convergence

In a spot convergence switch scenario, LPO modules connect servers, NICs, and switches with optimized power, cost, and latency. For example, Dell PowerSwitch Z9864F-ON switches can interoperate with Broadcom Thor 2 NICs using LPO optics, including DSPLPO variants, which are certified DSP-free modules for end-to-end optical links . This setup allows incremental deployment of LPO networks while maintaining high-speed connectivity and low operational costs.

DSPLPO Explained

DSPLPO stands for DSP-free Linear Pluggable Optics. These modules are designed to connect to remote LPO modules without requiring DSP-based signal processing at either end, reducing power usage and system complexity . While DSPLPO modules may have slightly shorter transmission distances due to higher bit error rates, they provide a scalable and flexible solution for high-speed optical networks.

Advantages and Considerations

• Power Efficiency: Eliminating DSPs reduces energy consumption in data centers .
• Low Latency: Direct signal handling through TIAs and ASICs minimizes processing delays .
• Flexibility: Pluggable modules can be hot-swapped and upgraded incrementally .
• Deployment Challenges: LPO systems may have reduced transmission distances and require careful SerDes compatibility, especially at 200G+ speeds .

Applications

LPO and DSPLPO are increasingly used in data centers, AI clusters, and mobile fronthaul networks, where low latency, high bandwidth, and energy efficiency are critical . Integrating LPO with optical switch fabrics enables all-optical transmission, supporting GPU/CPU-intensive workloads and high-speed server-to-switch interconnects. In summary, Lithuanian spot convergence switches using LPO and DSPLPO would leverage DSP-free optical modules to achieve high-speed, low-latency, and energy-efficient connectivity, while maintaining the flexibility and serviceability of pluggable optics .