The U.S. Department of Energy seeks a single vendor to replace all traditional landline telecommunications circuits with modernized services across multiple Nevada, California, New Mexico, and Maryland locations, supporting over 1.5 million annual calls and 25,000 DIDs. The contractor must provide a long-term solution including fiber/ethernet/SIP circuits, on-premises equipment, DID and 800# services, 911 support, and U.S.-based support staff. Performance locations include the Nevada National Security Site, North Las Vegas Facility, Remote Sensing Labs in Nevada and Maryland, and labs in California and New Mexico. No specific budget amount or submission timeline is mentioned in the description. The opportunity requires respondents to demonstrate capability under NAICS code 517810 and provide past performance records.