Multimode fiber optic cable used to connect the switch to the BRAS

Use duplex multimode fiber (OM3 or OM4) with SFP+ transceivers and LC connectors for high-speed switch-to-BRAS links.Recommended Fiber Type

For connecting a switch to a BRAS, OM3 or OM4 multimode fiber (MMF) is typically used. OM3 supports 10Gbps transmission up to 300 meters, while OM4 extends this distance to around 400 meters, making it suitable for most data center or campus deployments . OM5 fiber is also available and optimized for short wavelength division multiplexing (SWDM), allowing multiple wavelengths over a single fiber for longer distances, but OM3/OM4 remains the standard for most 10G links .

Transceivers

The connection requires SFP+ multimode transceivers, commonly referred to as 10GBASE-SR modules. These operate at 850 nm and are designed for short-reach, high-speed applications . SFP+ modules are hot-pluggable and compatible with duplex LC connectors, providing reliable 10Gbps connectivity between the switch and BRAS .

Cabling and Connectors

• Duplex fiber: Two strands are required—one for transmit (TX) and one for receive (RX).
• LC connectors: Most SFP+ modules use LC-style connectors, which are compact and widely supported .
• MTP/MPO options: For higher-density or multi-fiber deployments, MTP/MPO trunk cables can be used, typically with OM4 fiber, supporting multiple fibers under a single sheath .

Deployment Considerations

• Ensure the fiber type matches the SFP+ module (OM3/OM4 for 10GBASE-SR).
• Maintain proper polarity: connect TX on the switch to RX on the BRAS and vice versa.
• Use plenum-rated cables for indoor installations where fire safety is required .
• For distances beyond 400 meters at 10Gbps, consider single-mode fiber (OS2) instead of multimode.

Summary

To connect a switch to a BRAS using multimode fiber:

1. Use OM3 or OM4 duplex multimode fiber.
2. Install 10GBASE-SR SFP+ transceivers on both ends.
3. Terminate with LC connectors or use pre-terminated duplex cables.
4. Verify polarity and distance limitations to ensure reliable 10Gbps connectivity . This setup provides a cost-effective, high-speed, and low-latency connection suitable for enterprise and service provider networks.