N9K-C9400-SUP-A=: How Does Cisco\’s Enh
Hardware Architecture: The Backbone of Catalyst 9400 Op...
The GLC-FE-100BX-D= is a Cisco 100BASE-BX10 SFP (Small Form-Factor Pluggable) transceiver designed for single-mode fiber (SMF) networks. Unlike traditional dual-fiber modules, this bidirectional (BiDi) optic uses wavelength division multiplexing (WDM) to transmit and receive data over a single fiber strand. Operating at 1550 nm TX / 1310 nm RX, it supports distances up to 10 kilometers (6.2 miles), making it ideal for metro Ethernet, campus backbones, and ISP last-mile deployments.
Cisco’s Transceiver Module Compatibility Matrix confirms the GLC-FE-100BX-D= works with Catalyst 2960-X, 3850, and 9200 Series switches, as well as ASR 1000 routers. Its DOM (Digital Optical Monitoring) support enables real-time diagnostics for temperature, voltage, and TX/RX power via Cisco IOS commands like show interface transceiver details
.
A common installation error involves mismatched TX/RX wavelengths between paired BiDi modules. For example, connecting two GLC-FE-100BX-D= units will fail because both transmit at 1550 nm. Correct deployment requires one GLC-FE-100BX-D= (1550 nm TX) and one GLC-FE-100BX-U= (1310 nm TX) at opposite ends. Cisco’s Field Manual for Fiber Optics emphasizes verifying wavelength labels on SFPs before installation.
A 2023 case study by a European ISP revealed a 30% reduction in fiber trenching costs after replacing dual-strand 100BASE-FX links with GLC-FE-100BX-D=/U= pairs in their rural FTTH rollout.
For intermittent link drops, run show interface transceiver
to check for Rx Power Low warnings. If values fall below -23 dBm, inspect connectors or replace degraded fiber segments.
Counterfeit BiDi SFPs often fail to meet wavelength tolerances, causing packet loss or permanent switch port damage. Authentic GLC-FE-100BX-D= modules are available via itmall.sale’s Cisco-certified inventory, which includes lifetime warranty coverage and technical validation reports.
Having deployed GLC-FE-100BX-D= SFPs in oil refinery monitoring systems, I’ve seen firsthand how single-strand fiber solutions cut deployment timelines by weeks in remote areas. While 100 Mbps seems modest compared to modern multi-gigabit optics, this module fills a critical niche where infrastructure costs outweigh raw speed requirements. Organizations prioritizing TCO (Total Cost of Ownership) over bandwidth hype should treat the GLC-FE-100BX-D= as a cornerstone of their fiber strategy—especially when retrofitting legacy networks. Cisco’s commitment to backward compatibility ensures these SFPs remain relevant even as networks evolve toward 400G.