| Business | Phone |
| Sterling Communications Inc 2368 Canyon Dr, St Charles 63303 | (636) 922-2991 |
| Mci 500 Technology Dr, St Charles 63304 | (636) 793-1100 |
| Gla Network Technologies 17 Research Park Dr, St Charles 63304 | (636) 720-0900 |
| Complas Inc 509 Muirfield Dr, St Charles 63304 | (636) 926-0272 |