What do the Suffixes “SR8, SR8-C, SRBD, SR4, DR4/XDR4/PLR4, FR4/LR4 and 2FR4” Stand for?

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John Doe

Answered on 7:32 am

In general, the letters refer to reach or optics technology, and the number refers to the number of optical channels:

SR8: Short Range 8. This transceiver supports 400G transmission over multimode fiber (MMF) with a maximum reach of 100 meters. It uses a MPO-16 connector and PAM4 modulation.

SR8-C: Short Range 8 Copper. This transceiver supports 400G transmission over copper cable with a maximum reach of 3 meters. It uses a QSFP-DD connector and PAM4 modulation.

SRBD: Short Range Bidirectional. This transceiver supports 400G transmission over MMF with a maximum reach of 70 meters. It uses a duplex LC connector and PAM4 modulation.

SR4: Short Range 4. This transceiver supports 400G transmission over MMF with a maximum reach of 100 meters. It uses a MPO-12 connector and PAM4 modulation.

DR4 / XDR4 / PLR4: Data Center Reach 4 / eXtended Data Center Reach 4 / Parallel Long Reach 4. These transceivers support 400G transmission over single-mode fiber (SMF) with a maximum reach of 500 meters / 2 kilometers / 10 kilometers respectively. They use a MPO-12 connector and PAM4 modulation.

FR4 / LR4: Fiber Reach 4 / Long Reach 4. These transceivers support 400G transmission over SMF with a maximum reach of 2 kilometers / 10 kilometers respectively. They use a duplex LC connector and PAM4 modulation.

2FR4: Two Fiber Reach 4. This transceiver supports 400G transmission over SMF with a maximum reach of 2 kilometers. It uses two duplex LC connectors and coherent modulation.

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