Exhibit 21

FAIRPOINT COMMUNICATIONS, INC.  (formerly known as MJD Communications, Inc.)  SUBSIDIARIES

|Name                 |                                                           | Jurisdiction of Incorporation         
|-------------------- | --------------------------------------------------------- | --------------------------------------
|ST Enterprises, Ltd. |                                                           | Kansas                                
|                     | FairPoint Vermont, Inc.                                   |                                       
|                     | Sunflower Telephone Company, Inc.                         |                                       
|                     | Northland Telephone Company of Maine, Inc.                |                                       
|                     | ST Computer Resources, Inc.                               |                                       
|                     | ST Long Distance, Inc.                                    |                                       
|MJD Ventures, Inc.   |                                                           | Delaware                              
|                     | Marianna and Scenery Hill Telephone Company               |                                       
|                     |                                                           | Marianna Tel, Inc.                    
|                     | Bentleyville Communications Corporation                   |                                       
|                     |                                                           | BE Mobile Communications, Incorporated
|                     | The Columbus Grove Telephone Company                      |                                       
|                     |                                                           | Quality One Technologies, Inc.        
|                     | C-R Communications, Inc.                                  |                                       
|                     |                                                           | C-R Telephone Company                 
|                     |                                                           | C-R Long Distance, Inc.               
|                     | Taconic Telephone Corp.                                   |                                       
|                     |                                                           | Taconic Technology Corp.              
|                     |                                                           | Taconic TelCom Corp.                  
|                     | Ellensburg Telephone Company                              |                                       
|                     |                                                           | Elltel Long Distance Corp.            
|                     | Sidney Telephone Company                                  |                                       
|                     | Utilities, Inc.                                           |                                       
|                     |                                                           | Standish Telephone Company            
|                     |                                                           | China Telephone Company               
|                     |                                                           | Maine Telephone Company               
|                     |                                                           | UI Long Distance, Inc.                
|                     |                                                           | UI Communications, Inc.               
|                     |                                                           | UI Telecom, Inc.                      
|                     | Telephone Service Company                                 |                                       
|                     | Chouteau Telephone Company                                |                                       
|                     | Chautauqua and Erie Telephone Corporation                 |                                       
|                     |                                                           | Chautauqua & Erie Communications, Inc.
|                     |                                                           | (d/b/a C& E Teleadvantage)            
|                     |                                                           | C & E Communications, Ltd.            
|                     | The Orwell Telephone Company                              |                                       
|                     |                                                           | Orwell Communications, Inc.           
|                     | The Germantown Independent Telephone Company              |                                       
|                     |                                                           | Germantown Long Distance Company      
|                     |                                                           | GITCO Sales, Inc.                     
|                     |                                                           | GIT-CELL, Inc.                        
|                     | GTC Communications, Inc. (f/k/a TPG Communications, Inc.) |                                       
|                     |                                                           | St. Joe Communications, Inc.          
|                     |                                                           |                                       
|                     |                                                           |                                       
|                     |                                                           |                                       

---



|                                                                                       | Peoples Mutual Telephone Company                              |                                                   | Virginia                       
|-------------------------------------------------------------------------------------- | ------------------------------------------------------------- | ------------------------------------------------- | -------------------------------
|                                                                                       |                                                               | Peoples Mutual Services Company                   |                                
|                                                                                       |                                                               | Peoples Mutual Long Distance Company              |                                
|                                                                                       | Fremont Telcom Co.                                            |                                                   | Idaho                          
|                                                                                       |                                                               | Fremont Broadband, LLC                            |                                
|                                                                                       | Fretel Communications, LLC                                    |                                                   | Idaho                          
|                                                                                       | Comerco, Inc.                                                 |                                                   | Washington                     
|                                                                                       |                                                               | YCOM Networks, Inc.                               |                                
|                                                                                       | Berkshire Telephone Corporation                               |                                                   | New York                       
|                                                                                       |                                                               | Berkshire Cable Corp.                             |                                
|                                                                                       |                                                               | Berkshire Net, Inc.                               |                                
|                                                                                       |                                                               | Berkshire Cellular, Inc.                          |                                
|                                                                                       |                                                               |                                                   | Berkshire New York Access, Inc.
|                                                                                       | Community Service Telephone Co.                               |                                                   | Maine                          
|                                                                                       | Commtel Communications Inc.                                   |                                                   | Maine                          
|MJD Services Corp.                                                                     |                                                               | Delaware                                         
|                                                                                       | Bluestem Telephone Company                                    |                                                   | Delaware                       
|                                                                                       | Big Sandy Telecom, Inc.                                       |                                                   | Delaware                       
|                                                                                       | FairPoint Communications Missouri, Inc.                       |                                                   | Missouri                       
|                                                                                       | Odin Telephone Exchange, Inc.                                 |                                                   | Illinois                       
|                                                                                       | Columbine Telecom Company (f/k/a Columbine Acquisition Corp.) |                                                   | Delaware                       
|                                                                                       | Ravenswood Communications, Inc.                               |                                                   | Illinois                       
|                                                                                       |                                                               | The El Paso Telephone Company                     |                                
|                                                                                       |                                                               | El Paso Long Distance Company                     |                                
|                                                                                       | Unite Communications Systems, Inc.                            |                                                   | Missouri                       
|                                                                                       |                                                               | ExOp of Missouri, Inc.                            |                                
|                                                                                       | Yates City Telephone Company                                  |                                                   | Illinois                       
|FairPoint Carrier Services, Inc.                                                       |                                                               | Delaware                                         
|(f/k/a FairPoint Communications Solutions Corp., f/k/a FairPoint Communications Corp.) |                                                               |                                                  
|                                                                                       |                                                               | FairPoint Communications Solutions Corp.New York |                                
|                                                                                       |                                                               | FairPoint Communications Solutions Corp.Virginia |                                
|FairPoint Broadband, Inc.                                                              |                                                               | Delaware                                         
|FairPoint Logistics, Inc.(f/k/a MJD Capital Corp.)                                     |                                                               | South Dakota                                     
|Northern New England Telephone Operations LLC                                          |                                                               | Delaware                                         
|                                                                                       |                                                               | Telephone Operating Company of Vermont LLC        |                                
|Enhanced Communications of Northern New England Inc.                                   |                                                               | Delaware                                         

---



QuickLinks