J4859D-BCC | Aruba Compatible 1GB Single-Mode 10km (1000BASE-LX)

Q: Will this work in place of the Aruba J4859D?
A: Yes. This module matches the J4859D specification: SFP form factor, 1.25 Gbps data rate, 1310nm wavelength, 10km reach over single-mode fibre, and 1000BASE-LX/LH standard compliance. It is plug-and-play compatible with Aruba switches that accept the original J4859D.

Q: Which Aruba switches support this transceiver?
A: This module is compatible with Aruba 2530, 2920, 2930F, and 3810M series switches, as well as other Aruba platforms with SFP ports supporting Gigabit Ethernet transceivers. Verify your switch has a 1G SFP slot and runs firmware that recognises 1000BASE-LX/LH optics.

Q: Can I use this on multi-mode fibre instead of single-mode?
A: Yes, but with reduced reach and specific requirements. Over 50/125µm or 62.5/125µm OM2 multi-mode fibre, maximum distance is 550m. You must use a mode conditioning patch cable at the transmit end to offset the launch from the 1310nm single-mode laser into the multi-mode core, preventing differential mode delay that would otherwise corrupt the signal.

Q: How do I access the DOM data from this transceiver?
A: The module reports DOM parameters over the I2C interface defined in SFF-8472. On Aruba switches, use CLI commands such as 'show interfaces transceiver' or equivalent for your platform and firmware version. You will see live values for transmit power, receive power, temperature, supply voltage, and laser bias current, updated continuously while the link is operational.

Q: What is the actual link budget and how does it relate to the 10km reach specification?
A: This transceiver provides a minimum 15 dB optical budget between the transmit power (-9.5 to -3 dBm) and receive sensitivity (-20 to -3 dBm). The 10km reach assumes typical single-mode fibre attenuation of around 0.35 to 0.5 dB/km at 1310nm, plus connector and splice losses. Actual distance depends on your installed fibre quality, number of connectors, and any inline passive components. Always measure link loss or calculate from your fibre plant records to confirm margin.