RIO — IL
Data last updated: March 10, 2026
Area Codes
Top Carriers
| Carrier | OCN | NXX Count |
|---|---|---|
| CITIZENS TELECOM CO ILLINOIS-FRONTIER CITIZENS -IL | 1183 | 1 |
| ONEIDA NETWORK SERVICES, INC. | 4624 | 1 |
| STRATUS NETWORKS | 495J | 1 |
Data last updated: March 10, 2026
| Carrier | OCN | NXX Count |
|---|---|---|
| CITIZENS TELECOM CO ILLINOIS-FRONTIER CITIZENS -IL | 1183 | 1 |
| ONEIDA NETWORK SERVICES, INC. | 4624 | 1 |
| STRATUS NETWORKS | 495J | 1 |