The Cisco 12000 Series 4-Port OC-3c/STM-1c POS/SDH Line Card is a high-capacity, high-performance interface that is ideal for edge feature support and customer access applications. The 4-port OC-3/STM-1 card may be ordered with multimode, single mode intermediate reach, and single mode long reach optics enabling customers to connect directly to fiber or traditional SONET/SDH solutions.