Preserve installed fiber infrastructure with a compatible 1000BASE-LX GBIC designed for Avaya/Nortel environments that still anchor many enterprise networks. This AddOn module delivers Gigabit Ethernet over single-mode fiber at 1,310 nm and supports up to 10 km of reach, making it a practical fit for backbone links, inter-building runs, and long-haul switch uplinks. The LC connector keeps integration straightforward in standard SMF cabling plants, while the TAA-compliant designation supports procurement requirements in public sector and regulated environments. For teams managing mixed-vendor networks, a compatible replacement optic can reduce qualification effort and help keep spare inventory aligned with the installed base. This module is a focused option for organizations that need dependable optical performance without reworking the network design. It is suited to legacy Gigabit deployments where preserving compatibility, reach, and sourcing compliance matters more than chasing a lower-cost part with uncertain fit. When uptime depends on the fiber layer, a verified replacement optic is the safer path.