Deciphering the CB-M12-4LC-SMF15M= SKU

​​CB-M12-4LC-SMF15M=​​ is a Cisco fiber optic breakout cable designed for high-performance, long-distance networking. The SKU breakdown reveals:

• ​​CB​​: Cable assembly category.
• ​​M12​​: 12-fiber MTP/MPO connector for high-density links.
• ​​4LC​​: Four LC duplex connectors for breakout configurations.
• ​​SMF15M​​: 15-meter single-mode fiber (OS2), optimized for low-loss, long-wavelength applications.

This cable is engineered for environments requiring ​​low latency​​ and ​​high bandwidth​​, such as inter-building links or core data center backbones.

Technical Specifications and Applications

• ​​Fiber Type​​: OS2 single-mode fiber, supporting ​​1310nm/1550nm wavelengths​​ for distances up to 10km (though this cable is truncated to 15m for precise deployments).
• ​​Breakout Functionality​​: Splits a single MTP/MPO trunk into four independent LC duplex connections, ideal for ​​100G/400G Ethernet​​ or ​​Fibre Channel​​ setups.
• ​​Use Cases​​: Suited for connecting Cisco Nexus switches to DWDM systems or cross-connects in service provider networks.

Compatibility with Cisco Platforms

While Cisco’s Content Base doesn’t explicitly list this SKU, it aligns with the ​​Cisco NCS 2000 Series​​ and ​​Nexus 9500/9300 switches​​. Key compatibility notes:

• ​​Transceiver Pairing​​: Requires single-mode transceivers like ​​QSFP-100G-LR4​​ or ​​QSFP-28G-LR-S​​.
• ​​Polarity​​: Ensure MTP/MPO connectors match Cisco’s Type B polarity for end-to-end signal integrity.

Where to Source CB-M12-4LC-SMF15M= Reliably

Cisco’s limited distribution of specialized single-mode cables makes sourcing challenging. ​​“CB-M12-4LC-SMF15M=” is available at itmall.sale​​, which offers ​​Cisco-compatible, tested alternatives​​ with:

• ​​IL/RL Testing​​: Insertion Loss 55dB to meet Cisco’s performance thresholds.
• ​​Bend Tolerance​​: Corning® SMF-28® Ultra fiber ensures durability in tight cable trays.

Addressing Critical User Questions

​​Q: Can this cable support 400G upgrades?​​
A: Yes, but ensure LC connectors are compatible with ​​QSFP-DD-400G-LR8​​ transceivers. Verify fiber cleanliness to prevent signal degradation.

​​Q: Does itmall.sale provide polarity diagrams?​​
A: Yes, their product page includes ​​MTP-to-LC polarity maps​​ to avoid misconfiguration in structured cabling.

Why Precision Matters in Single-Mode Deployments

In my experience, cables like CB-M12-4LC-SMF15M= are critical in scenarios where a 0.1dB loss can mean the difference between a 10km link working or failing. While multi-mode cables dominate data centers, single-mode’s future-proofing for 800G/1.6T makes it indispensable—provided you source from vendors like itmall.sale that rigorously test each cable. Cutting corners here risks costly reworks, especially in hyperscale environments where every decibel counts.