The Cisco NM-1A-OC3-POM network module is a high performance single-width, single-port ATM network module, utilizing an optical carrier level 3 (OC-3) link. The ATM interface is a small form-factor pluggable (SFP) optical port. Fiber-optic cables to the network are attached to an SFP module that is inserted into the SFP port. The mode of operation is determined by the SFP module that is used.