OC3-2M MMF W/CPU-2 clei The OC3-2M MMF Card with CPU-2 is a local ATM (LATM) OC3 interface card operating at the SONET OC3 rate of 155 Mbps, with 32k cell buffering per card. The multi-mode fiber (MMF) optional interface has a typical range of 2km. The OC3-2M MMF Card is a single port card and is compliant to the requirements of the ATM Forum UNI Specification (Version 3.1) and the ATM Forum B-ICI Specification (Version 2.0). This card is designed to accept the optional Multi-Service Traffic Module (MSTM, 90-4724-01) or enhanced Traffic Shaping Module (eTM, 90-7695-01) which, when installed, provides enchanced traffic management features. This card is also supported on R2.0 of the 7670 ESE. Note that only the eTM is supported for traffic shaping on the ESE.