The POSIP-OC3-40 comes configured with 32 MB of dynamic random-access memory (DRAM) and 2 MB of static random-access memory (SRAM) as the factory default memory configurations. The Packet OC-3c Interface Processor (POSIP) provides a single 155.520-Mbps, OC-3c network interface, which provides a direct connection between the high-speed Cisco Extended Bus (CxBus or CyBus) and your external networks. The physical layer interface on the POSIP is OC-3c.