| Business | Phone |
| Bay Networks 9450 Bryn Mawr Ave, Des Plaines 60018 | (847) 447-2001 |
| Business Communication Anlysts 2500 E Devon Ave, Des Plaines 60018 | (847) 299-3720 |
| Communication Technical Svc 1153 Lee St, Des Plaines 60016 | (847) 298-2500 |
| Comsys Services Llc 6400 Shafer Ct 740, Des Plaines 60018 | (847) 384-0773 |