JUNIPER EX-SFP-GE40KT15R13 Switch Modules & Cards

EX-SFP-GE40KT15R13 40km BX Downlink Optic

EX-SFP-GE40KT15R13 is the downlink-side member of Juniper's 40km single-fiber 1000BASE-BX pair. It transmits at 1550nm, receives at 1310nm and uses a simplex LC PC/UPC connector. The Hardware Compatibility Tool maps it to Juniper part number 740-020426 and confirms digital optical monitoring.

Pairing direction is the SKU value

The correct far-end module is EX-SFP-GE40KT13R15. That 13R15 optic transmits on the wavelength this module receives, and receives the wavelength this module transmits. Purchasing two 15R13 units does not create a working BiDi pair even though both fit an SFP cage.

Receive power must stay inside range

Juniper documents the 40km BX pair on single-mode fiber with endpoint-specific optical limits. Measure the actual path, including patch panels, splices and connectors, and add design margin. A short laboratory jumper may require attenuation if received power would exceed the module maximum; a long path must still clear receiver sensitivity under worst-case conditions.

Platform qualification

Validate the exact host platform, interface module and Junos release in Juniper's HCT. Check that the port runs 1GbE and supports the Juniper BX optic, then verify DOM readings and alarms. A generic third-party EEPROM match is not equivalent to Juniper platform qualification.

Acceptance evidence

Record both endpoint PIDs, serials, fiber strand, TX/RX direction and optical levels. Confirm zero wavelength reversal, clean connectors, stable DOM values and error-free traffic under the intended load before closing the circuit.

Do not confuse this single-fiber BX part with EX-SFP-GE80KCW1470, which uses a duplex LC connection and a CWDM wavelength plan.

Official evidence: Juniper exact optic overview and part number, Juniper 40km BX endpoint and optical specifications and Juniper EX platform ordering description.