RX-Only BiDi Transceivers for Passive Network Visibility

Profitap RX-only BiDi transceivers are engineered for passive network monitoring, where transmit capability back into the network poses a liability. By completely removing the transmit path, these modules minimize risk, reduce power consumption, and guarantee unidirectional data flow.

What makes RX-only transceivers different

One-Way optical communication

RX-Only BiDi transceivers are different from standard transceivers because the transmit (TX) function is disabled at the hardware level. The components required to power and drive the TX laser are physically removed. As a result, the module cannot transmit under any circumstances. This creates accurate one-way optical communication, preventing signal injection, accidental link negotiation, and any impact on the production network.

These transceivers are indispensable for sensitive applications, such as monitoring in regulated industries and oversight of critical infrastructure.

Designed for passive monitoring

RX-only transceivers were specifically designed to receive network traffic, making them ideal for exclusively:

• Deterministic operation: Ensures predictable port behavior.
• Safety: Ideal for non intrusive monitoring.
• Precision: Guarantees clean packet acquisition for subsequent filtering, aggregation, and distribution.

Bi-directional transmission over standard duplex LC fiber

Both RX-only modules utilize bi-directional (BiDi) optics over conventional duplex LC multimode fiber. This is achieved by transmitting traffic on each fiber at distinct wavelengths (approximately 850 nm and 900–910 nm).

This BiDi approach provides significant advantages:

• Infrastructure reuse: Compatible with existing OM3 and OM4 fiber deployments.
• Simplified cabling: Removes the requirement for MPO or ribbon cabling.
• Ease of installation: Streamlines cabling within monitoring racks and data centers.

RX-Only monitoring at 40G

The PT-40G-SR-BD-RX is a QSFP+ receive-only transceiver designed for environments where 40G monitoring is still widely deployed.

Typical use cases

• Passive monitoring of 40G backbone links
• Optical TAP outputs connected to packet brokers
• Aggregation of multiple 40G feeds into a Packet Broker
• Cost-effective monitoring in transitional data center environments

RX-Only Monitoring at 100G

The PT-100G-SR-BD-RX extends the RX-only concept to modern 100G monitoring deployments using QSFP28 interfaces.

Typical use cases

• High-speed data center spine monitoring
• Security analytics platforms operating at 100G
• Optical TAP outputs feeding a Network Packet Broker 
• Lawful interception and compliance-driven monitoring environments
• IDS, NDR, and traffic forensics solutions

Why RX-Only transceivers matter

RX-only optics offer advantages that standard transceivers cannot provide in monitoring environments, including physical enforcement of one-way traffic flow, reduced operational and security risks, simplified compliance with regulatory requirements, fewer active optical components, and lower failure rates, as well as an optimized cost structure for passive monitoring deployments.

Conclusion

Profitap RX-only BiDi transceivers are not modified production optics. They are purpose-built components explicitly designed for passive monitoring.

• PT-40G-SR-BD-RX enables reliable RX-only monitoring at 40G
• PT-100G-SR-BD-RX enables scalable RX-only monitoring at 100G

In network visibility architectures, the objective is to receive traffic. Transmitting traffic is a risk. RX-only transceivers eliminate that risk by design.