EX-SFP-1GE-LX40K-BCC | Juniper Compatible 1GB Single-Mode ER - 40km (1000BASE-EX)

Q: Will this work in place of the Juniper EX-SFP-1GE-LX40K?
A: Yes. This transceiver is a plug-and-play replacement for the Juniper EX-SFP-1GE-LX40K. It matches the form factor, data rate (1.25 Gbps), wavelength (1310nm), connector type (LC duplex), and 40km reach over single-mode fiber. It is programmed to initialize identically in Juniper platforms.

Q: Which Juniper platforms support this transceiver?
A: This SFP is compatible with Juniper EX-Series Ethernet switches and other Juniper platforms with SFP slots that support 1000BASE-X standards, including models such as EX2200, EX2300, EX3200, EX3300, EX3400, and EX4200 series. Any Juniper device with an SFP port supporting Gigabit Ethernet over fiber will accept this module.

Q: What fiber type and quality is required to achieve the full 40km reach?
A: The 40km reach specification is based on G.652 standard single-mode fiber (9/125 micron) with typical attenuation of 0.4 dB/km at 1310nm. Actual reach depends on total link loss budget, which includes fiber attenuation, splice loss, connector loss, and any inline components. The transceiver provides approximately 17 dB optical budget. Fiber spans exceeding 35km or with multiple splices may require optical time-domain reflectometer (OTDR) testing to verify end-to-end loss.

Q: Can I use this module back-to-back without fiber attenuation?
A: Direct back-to-back connection (zero fiber span) is not recommended without an inline attenuator. The high transmit power designed for 40km reach can saturate the receiver at the far end, causing bit errors or link instability. If testing without fiber, install a 5 dB LC inline optical attenuator between the cable and the receiving port on each end to prevent receiver overload.

Q: Does this transceiver support Forward Error Correction (FEC)?
A: No. This is a 1000BASE-EX transceiver operating at 1.25 Gbps with 8b/10b encoding, which predates FEC implementation in optical modules. FEC is typically found in 10G and higher-speed transceivers (10GBASE-R and above). The 1000BASE-X physical layer relies on 8b/10b encoding for DC balance and error detection but does not include FEC capability. Link reliability over 40km is achieved through the optical power budget rather than forward error correction.