CISCO GLC-BX-D= 1000BASE-BX10 Downstream SFP Module 1 Gbps 1 x LC

The Cisco GLC-BX-D= is a hot-swappable 1 Gbps 1000BASE-BX10 downstream SFP transceiver for network administrators connecting compatible Cisco switches over single-mode fiber for links up to 10 km.

Recommended For

• Network administrators connecting two 1GbE devices over a point-to-point single-mode fiber link when only one fiber strand is available; the far end must use a matching 1000BASE-BX10-U optic.
• Teams extending a 1GbE connection between network closets, buildings, or other sites over compatible single-mode fiber, where a link rated for up to 10 km meets the route’s distance and optical-budget requirements.
• Cisco network operators replacing or provisioning an optic in a host device that explicitly supports the GLC-BX-D=, after checking the device’s transceiver compatibility requirements.
• Installers seeking a bidirectional 1GbE link with digital optical monitoring, when both the fiber plant and network equipment support the required single-mode optic.

Real-World Use Scenarios

• Connecting two compatible switches over a single strand of single-mode fiber: pair this downstream module with a matching upstream GLC-BX-U at the other end, and the link can carry bidirectional 1 Gbps traffic over a route up to 10 km, subject to the fiber path and equipment compatibility.
• Linking a campus or business building to a remote network closet: when compatible switches and a suitable single-mode fiber route are already in place, the module provides a 1 Gbps link without needing a two-strand fiber pair.
• Making use of a fiber route with only one available strand: a correctly matched downstream/upstream BiDi pair can provide a full-duplex switch connection over that strand, helping avoid the need to install or reserve a second strand.
• Connecting network equipment across a leased or provider-managed fiber handoff: where the handoff uses single-mode fiber and a compatible 1 Gbps BiDi optic pair, this module can serve as the downstream end of the connection; confirm the provider’s optic and wavelength requirements first.
• Checking a deployed fiber link during troubleshooting: on supported equipment, digital optical monitoring can help a technician inspect optical readings, making it easier to investigate a link that is down or behaving intermittently.

Spec Summary