The single-port Cisco Gigabit Ethernet Network Module (part number NM-1GE) provides Gigabit Ethernet optical and copper connectivity for access routers. The module is supported by the Cisco 2691, Cisco 3660, Cisco 3725, Cisco 3745, Cisco 3825, and Cisco 3845 series routers. This network module has one gigabit interface converter (GBIC) slot to carry any standard copper or optical Cisco GBIC (see Table 1 for details). The flexibility to use different GBICs allows for making a choice depending on various factors, such as distance, cost, existing infrastructure, future expansion plans, and requirements.