teleSys Software, Inc.

teleSys Software is a San Mateo boutique telecom firm that has quietly kept the world's phone calls and texts connected since 1997. It builds carrier-grade signaling software - the invisible traffic-control layer that routes 2G, 3G, 4G, and 5G networks - including Diameter Signaling Controllers, SS7/SIGTRAN transfer points, signaling firewalls, and 5G SCPs. Its MACH7 product line runs in 400+ installations across 100+ operators worldwide, serving more than 500 million subscribers through the major Tier 1 carriers.