How to Choose the Right MPO/MTP Cable for 400G/800G Transceivers

MPO/MTP Cabling Guide: Match Fiber Patch Cords to Transceivers for Hyperscale Networks

As 400G/800G data centers and 5G fronthaul networks demand higher density and lower latency, selecting the correct MPO/MTP cable for your optical transceiver is critical. This guide simplifies compatibility checks, polarity rules, and future-proofing strategies to optimize hyperscale cabling performance.

Step 1: Verify Transceiver Compatibility

A. Fiber Type

• OM5 Fiber: Essential for SWDM (Short Wavelength Division Multiplexing) and 400G-SR8 transceivers. Supports 40G/100G/400G up to 150m.

• OS2 Fiber: Enables 400G-ZR coherent optics for 80–120km links.

B. MPO Connector Size

• MPO-12: For 40G (e.g., QSFP-40G-SR4) and 100G-SR4 transceivers.

• MPO-24/APC: Required for 800G-SR8 and coherent CPO (Co-Packaged Optics).

C. Data Rate & Distance

• 40G/100G-MMF: OM4 supports 150m at 100G; OM5 extends to 150m for 400G.

• 400G/800G-SMF: OS2 with ER4/LR8 transceivers for 2–120km.

Step 2: Select Polarity Type (TIA-568 Standard)

Polarity Schemes

Pro Tip: For 400G-SR8/DR4, use Type B with MPO-24 trunks to avoid mid-span polarity flips.

Step 3: Confirm Gender & Connector Polish

• Gender:

• Male (Pinned): Connects to transceivers.

• Female (Unpinned): Links between patch panels.

• Polish Type:

• UPC (Ultra Physical Contact): For MM/SM up to 100G.

• APC (Angled Physical Contact): Mandatory for DWDM/PON to reduce back reflection.

Step 4: Calculate Cable Length & Loss Budget

• Attenuation Limits:

• OM4 @ 850nm: 3.0 dB/km (Max 1.5 dB loss for 100m 400G-SR8).

• OS2 @ 1310nm: 0.4 dB/km (Max 5.0 dB for 40km 400G-LR4).

• Length Guidelines:

• Intra-Rack: 1–5m LC-MPO breakout cables.

• Inter-Rack: 10–30m MPO-12 trunks.

• Long-Haul: 50–300m low-loss MPO-24 harnesses.

Step 5: Future-Proof with MPO-24 & OM5

• MPO-24: Prepares for 800G-LR and 1.6T transceivers using 16x25G lanes.

• OM5 + SWDM: Enables 200m 400G-SR4.2 without re-cabling.

Case Study: 400G QSFP-DD-SR8 Deployment

1. Transceiver: QSFP-DD-400G-SR8 (850nm VCSEL, MPO-24).

2. Cable: OM5 MPO-24 Type B (Female-to-Female).

3. Polarity: Type B cross-connect between spine/leaf switches.

4. Length: 75m (within OM5’s 150m limit for 400G).

Conclusion: Optimize for Hyperscale & Coherent Optics

• Hyperscale DCs: Prioritize MPO-24 OM5 trunks and Type B polarity.

• 5G Transport: Use APC-MPO OS2 cables for 400G-ZR coherence.

• Legacy Upgrades: Deploy MPO-12-to-LC breakout cables for hybrid 10G/40G networks.