JL309A - Aruba 100G QSFP28 MPO SR4 MMF Transceiver

Aruba JL309A — 100G QSFP28 MPO SR4 multimode transceiver (100m)

What it is

JL309A is a 100GbE QSFP28 optical transceiver from Aruba/HPE’s X151 optics line. It’s the standard 100GBASE-SR4 short-reach module for multimode fiber, using a parallel 4-lane 850nm design over an MPO/MTP-12 connector. Think “default 100G optic for short in-building / data-center MMF runs.”

Why buyers pick JL309A (plain English)

• Easy, standard 100G over multimode
  The go-to for short-reach 100G links inside a data center or campus building.

• High density, clean cabling
  One QSFP28 port gives 100G without bundling multiple 10/25G links.

• Great for leaf-spine and core uplinks
  SR4 is the common choice when your fiber plant is OM3/OM4 and distances are short.

• Breakout-friendly
  Can be used for 100G → 4×25G SR breakout if your switch supports it and you use the right MPO breakout cable.

60-second spec box (JL309A)

Form factor

• QSFP28 (100GbE)

Type / standard

• 100GBASE-SR4 (Short Reach, 4-lane parallel optics)

Fiber / connector

• Multimode fiber (MMF)

• MPO / MTP-12 connector

Wavelength

• 850 nm

Max distance (typical)

• Up to ~70 m on OM3 MMF

• Up to ~100 m on OM4 MMF

Lane structure

• 4 × 25Gb/s lanes (Tx/Rx) for 100Gb/s aggregate

Diagnostics

• DOM/DDM supported

Use case

• 100G switch-to-switch or switch-to-server links over short MMF runs

Where it fits (and when to choose something else)

Perfect for:

• Data center leaf-to-spine, TOR-to-aggregation, core uplinks on OM3/OM4

• Short campus backbone runs inside the same building

• 100G ports that may need 4×25G breakout

Choose something else if:

• You need longer reach → use 100GBASE-LR4 / CWDM4 on single-mode

• Your run is very short in-rack → QSFP28 DAC/AOC is usually cheaper

TL;DR

JL309A is the Aruba 100G QSFP28 SR4 MMF optic:
850nm over MPO-12, ~70m OM3 / ~100m OM4 — the standard short-reach 100GbE transceiver for Aruba CX and high-speed campus/data-center links.