| Business | Phone |
| Hci Technologies Inc 45300 Catalina Ct, Sterling 20166 | (703) 736-3000 |
| All-Com Communications Inc 20426 White Oak Dr, Sterling 20165 | (703) 404-3625 |
| Bridgman Communications Inc 45064 Underwood Ln 100, Sterling 20166 | (703) 471-4700 |
| E-Tel Systems Corp 43766 Trade Center Pl 140, Sterling 20166 | (703) 904-1700 |
| Pti 1334 Shepard Dr E, Sterling 20164 | (703) 406-4300 |