Which series of routers provides metro optical transport through plug-in modules deploying 10 Gbps?

The Cisco ONS series and the 7600 series are specifically designed to handle high-capacity data transport, including metropolitan area networks (MANs) that require reliable and high-speed optical transport. These series support various plug-in modules that can deliver 10 Gbps transmission speeds, making them ideal for environments where robust, high-speed transport of data over short to medium distances is required.

The Cisco ONS (Optical Networking System) series is engineered for optical networking solutions, facilitating the management of bandwidth and services across metropolitan optical networks. The Cisco 7600 series, on the other hand, operates as a high-performing service provider edge router, capable of handling extensive data traffic and advanced services, thus making it suitable for metro transport scenarios.

In contrast, the other series mentioned, like the Cisco 800, 2900, and 3900 series, are primarily designed for different applications. The 800 series routers are targeted mainly at small office or branch environments; the 2900 series focuses on small to mid-sized enterprise applications, while the 3900 series offers some modular capabilities, but is typically more associated with enterprise routing rather than specifically supporting metro optical transport at the mentioned speeds.