Exhibit 4.4



 Exhibit 4.4 
 JOINDER AGREEMENT 
 December 6, 2010 

Pursuant to Section 3(j) of the Purchase Agreement, such section being an inducement to the Representatives (on behalf of the
Initial Purchasers) referred to below to execute the Purchase Agreement, the undersigned hereby execute this joinder agreement (this “Joinder Agreement”), whereby each of the undersigned agrees, on a joint and several basis, to accede to
the terms of the Registration Rights Agreement (the “Registration Rights Agreement”), dated as of December 2, 2010 (the “Issue Date”), between PAETEC Escrow Corporation (the “Escrow Issuer”), a Delaware corporation
and a wholly-owned subsidiary of PAETEC Holding Corp. (the “Parent”), and Deutsche Bank Securities Inc. (“DB”), Merrill Lynch, Pierce, Fenner & Smith Incorporated (“ML” and, together with DB, the
“Representatives”), Goldman Sachs & Co. (“GS”) and Morgan Stanley & Co. Incorporated (“MS” and, together with the Representatives and GS, the “Initial Purchasers”). Capitalized terms used in
this Joinder Agreement without definition have the respective meanings given to them in the Registration Rights Agreement. 

The Parent hereby undertakes to perform all of the obligations of the Company set forth therein, as though the Parent had entered into
the Registration Rights Agreement on the Issue Date. Each of the undersigned PAETEC Guarantors and Cavalier Entities undertakes to perform, on a joint and several basis, all of the obligations of the Note Guarantors set forth therein, as though the
undersigned PAETEC Guarantors and Cavalier Entities had entered into the Registration Rights Agreement on the Issue Date. Each of the undersigned agrees that such obligations include, without limitation, (a) the Parent’s assumption of all
of the obligations of the Company to perform and comply with all of the agreements thereof contained in the Registration Rights Agreement, (b) the PAETEC Guarantors’ and Cavalier Entities’ assumption of all of the obligations of the
Note Guarantors to perform and comply with all of the agreements thereof contained in the Registration Rights Agreement and (c) the Parent’s, the PAETEC Guarantors’ and the Cavalier Entities’ assumption, to the same extent as set
forth therein but on a joint and several basis, of all of the Company’s and the Note Guarantors’ indemnification and other obligations contained in Section 8 of the Registration Rights Agreement. 

This Joinder Agreement shall be governed by and construed in accordance with the laws of the State of New York applicable to agreements
made and to be performed in New York State. 
 This Joinder Agreement may be executed in any number of counterparts and by the
parties hereto in separate counterparts, each of which when so executed shall be deemed to be an original and all of which taken together shall constitute one and the same agreement. Delivery of an executed counterpart of a signature page by
facsimile, e-mail or other electronic means shall be effective as delivery of a manually executed counterpart. 

*        *        * 







 IN WITNESS WHEREOF, the parties hereto have executed this Joinder Agreement as of the date
first written above. 
  

			
	PAETEC HOLDING CORP.
		
	By:	 	/s/ Keith M. Wilson
	 Name:
 Title:
	 	 Keith M. Wilson
 Executive
Vice President and Chief Financial Officer



  
  

			
	PAETEC GUARANTORS:
	
	US LEC LLC
		
	By:	 	/s/ Keith M. Wilson
	 Name:
 Title:
	 	 Keith M. Wilson
 Executive
Vice President and Chief Financial Officer



  

			
	PAETEC CORP.
		
	By:	 	/s/ Keith M. Wilson
	 Name:
 Title:
	 	 Keith M. Wilson
 Executive
Vice President and Chief Financial Officer



  
  

			
	US LEC COMMUNICATIONS LLC
		
	By:	 	/s/ Keith M. Wilson
	 Name:
 Title:
	 	 Keith M. Wilson
 Executive
Vice President and Chief Financial Officer










  

			
	US LEC OF NORTH CAROLINA LLC
		
	By:	 	/s/ Keith M. Wilson
	 Name:
 Title:
	 	 Keith M. Wilson
 Executive
Vice President and Chief Financial Officer



  

			
	US LEC OF ALABAMA LLC
		
	By:	 	/s/ Keith M. Wilson
	 Name:
 Title:
	 	 Keith M. Wilson
 Executive
Vice President and Chief Financial Officer



  

			
	US LEC OF FLORIDA LLC
		
	By:	 	/s/ Keith M. Wilson
	 Name:
 Title:
	 	 Keith M. Wilson
 Executive
Vice President and Chief Financial Officer



  

			
	US LEC OF GEORGIA LLC
		
	By:	 	/s/ Keith M. Wilson
	 Name:
 Title:
	 	 Keith M. Wilson
 Executive
Vice President and Chief Financial Officer



  

			
	US LEC OF TENNESSEE LLC
		
	By:	 	/s/ Keith M. Wilson
	 Name:
 Title:
	 	 Keith M. Wilson
 Executive
Vice President and Chief Financial Officer



  

			
	US LEC OF SOUTH CAROLINA LLC
		
	By:	 	/s/ Keith M. Wilson
	 Name:
 Title:
	 	 Keith M. Wilson
 Executive
Vice President and Chief Financial Officer










  

			
	PAETEC ITEL, L.L.C.
		
	By:	 	/s/ Keith M. Wilson
	 Name:
 Title:
	 	 Keith M. Wilson
 Executive
Vice President and Chief Financial Officer



  

			
	PAETEC INTEGRATED SOLUTIONS GROUP, INC.
		
	By:	 	/s/ Keith M. Wilson
	 Name:
 Title:
	 	 Keith M. Wilson
 Executive
Vice President and Chief Financial Officer



  

			
	PAETEC SOFTWARE CORP.
		
	By:	 	/s/ Keith M. Wilson
	 Name:
 Title:
	 	 Keith M. Wilson
 Executive
Vice President and Chief Financial Officer



  

			
	PAETEC COMMUNICATIONS, INC.
		
	By:	 	/s/ Keith M. Wilson
	 Name:
 Title:
	 	 Keith M. Wilson
 Executive
Vice President and Chief Financial Officer



  

			
	PAETEC COMMUNICATIONS OF VIRGINIA, INC.
		
	By:	 	/s/ Keith M. Wilson
	 Name:
 Title:
	 	 Keith M. Wilson
 Executive
Vice President and Chief Financial Officer










  

			
	US LEC OF MARYLAND LLC
		
	By:	 	/s/ Keith M. Wilson
	 Name:
 Title:
	 	 Keith M. Wilson
 Executive
Vice President and Chief Financial Officer



  

			
	US LEC OF VIRGINIA L.L.C.
		
	By:	 	/s/ Keith M. Wilson
	 Name:
 Title:
	 	 Keith M. Wilson
 Executive
Vice President and Chief Financial Officer



  

			
	US LEC OF PENNSYLVANIA LLC
		
	By:	 	/s/ Keith M. Wilson
	 Name:
 Title:
	 	 Keith M. Wilson
 Executive
Vice President and Chief Financial Officer



  

			
	ALLWORX CORP.
		
	By:	 	/s/ Keith M. Wilson
	 Name:
 Title:
	 	 Keith M. Wilson
 Executive
Vice President and Chief Financial Officer



  

			
	MPX, INC.
		
	By:	 	/s/ Keith M. Wilson
	 Name:
 Title:
	 	 Keith M. Wilson
 Executive
Vice President and Chief Financial Officer



  

			
	TECHNOLOGY RESOURCE SOLUTIONS, INC.
		
	By:	 	/s/ Keith M. Wilson
	 Name:
 Title:
	 	 Keith M. Wilson
 Executive
Vice President and Chief Financial Officer










  

			
	MCLEODUSA LLC
		
	By:	 	/s/ Keith M. Wilson
	 Name:
 Title:
	 	 Keith M. Wilson
 Executive
Vice President and Chief Financial Officer



  

			
	MCLEODUSA INFORMATION SERVICES, LLC
		
	By:	 	/s/ Keith M. Wilson
	 Name:
 Title:
	 	 Keith M. Wilson
 Executive
Vice President and Chief Financial Officer



  

			
	MCLEODUSA TELECOMMUNICATIONS SERVICES, L.L.C.
		
	By:	 	/s/ Keith M. Wilson
	 Name:
 Title:
	 	 Keith M. Wilson
 Executive
Vice President and Chief Financial Officer



  

			
	MCLEODUSA PURCHASING, L.L.C.
		
	By:	 	/s/ Keith M. Wilson
	 Name:
 Title:
	 	 Keith M. Wilson
 Executive
Vice President and Chief Financial Officer



  

			
	U.S. ENERGY PARTNERS LLC
		
	By:	 	/s/ Keith M. Wilson
	 Name:
 Title:
	 	 Keith M. Wilson
 Executive
Vice President and Chief Financial Officer



  

			
	PAETEC REALTY LLC
		
	By:	 	/s/ Keith M. Wilson
	 Name:
 Title:
	 	 Keith M. Wilson
 Executive
Vice President and Chief Financial Officer










  

			
	QUAGGA CORPORATION
		
	By:	 	/s/ Keith M. Wilson
	Name:	 	Keith M. Wilson
	Title:	 	Executive Vice President and Chief Financial Officer


  

			
	
	CAVALIER ENTITIES
	
	ACCESS ONE COMMUNICATIONS CORP.
		
	By:	 	/s/ Keith M. Wilson
	Name:	 	Keith M. Wilson
	Title:	 	Executive Vice President and Chief Financial Officer


  

			
	CAVALIER TELEPHONE CORPORATION
		
	By:	 	/s/ Keith M. Wilson
	Name:	 	Keith M. Wilson
	Title:	 	Executive Vice President and Chief Financial Officer


  

			
	COMPCO, INC.
		
	By:	 	/s/ Keith M. Wilson
	Name:	 	Keith M. Wilson
	Title:	 	Executive Vice President and Chief Financial Officer


  

			
	ELANTIC NETWORKS, INC.
		
	By:	 	/s/ Keith M. Wilson
	Name:	 	Keith M. Wilson
	Title:	 	Executive Vice President and Chief Financial Officer









  

			
	INTELLIFIBER NETWORKS, INC.
		
	By:	 	/s/ Keith M. Wilson
	Name:	 	Keith M. Wilson
	Title:	 	Executive Vice President and Chief Financial Officer


  

			
	LDMI TELECOMMUNICATIONS, INC.
		
	By:	 	/s/ Keith M. Wilson
	Name:	 	Keith M. Wilson
	Title:	 	Executive Vice President and Chief Financial Officer


  

			
	NETWORK TELEPHONE CORPORATION
		
	By:	 	/s/ Keith M. Wilson
	Name:	 	Keith M. Wilson
	Title:	 	Executive Vice President and Chief Financial Officer


  

			
	NT CORPORATION
		
	By:	 	/s/ Keith M. Wilson
	Name:	 	Keith M. Wilson
	Title:	 	Executive Vice President and Chief Financial Officer


  

			
	OMNICALL, INC.
		
	By:	 	/s/ Keith M. Wilson
	Name:	 	Keith M. Wilson
	Title:	 	Executive Vice President and Chief Financial Officer


  

			
	TALK AMERICA INC.
		
	By:	 	/s/ Keith M. Wilson
	Name:	 	Keith M. Wilson
	Title:	 	Executive Vice President and Chief Financial Officer









  

			
	TALK AMERICA HOLDINGS, INC.
		
	By:	 	/s/ Keith M. Wilson
	Name:	 	Keith M. Wilson
	Title:	 	Executive Vice President and Chief Financial Officer


  

			
	TALK AMERICA OF VIRGINIA, INC.
		
	By:	 	/s/ Keith M. Wilson
	Name:	 	Keith M. Wilson
	Title:	 	Executive Vice President and Chief Financial Officer


  

			
	TC SERVICES HOLDING CO., INC.
		
	By:	 	/s/ Keith M. Wilson
	Name:	 	Keith M. Wilson
	Title:	 	Executive Vice President and Chief Financial Officer


  

			
	THE OTHER PHONE COMPANY, INC.
		
	By:	 	/s/ Keith M. Wilson
	Name:	 	Keith M. Wilson
	Title:	 	Executive Vice President and Chief Financial Officer


  

			
	CAVALIER IP TV, LLC
		
	By:	 	/s/ Keith M. Wilson
	Name:	 	Keith M. Wilson
	Title:	 	Executive Vice President and Chief Financial Officer


  

			
	CAVALIER SERVICES, LLC
		
	By:	 	/s/ Keith M. Wilson
	Name:	 	Keith M. Wilson
	Title:	 	Executive Vice President and Chief Financial Officer


  







  

			
	CAVALIER TELEPHONE, L.L.C.
		
	By:	 	/s/ Keith M. Wilson
	Name:	 	Keith M. Wilson
	Title:	 	Executive Vice President and Chief Financial Officer


  

			
	CAVALIER TELEPHONE MID-ATLANTIC, L.L.C.
		
	By:	 	/s/ Keith M. Wilson
	Name:	 	Keith M. Wilson
	Title:	 	Executive Vice President and Chief Financial Officer


  

			
	CAVTEL HOLDINGS, LLC
		
	By:	 	/s/ Keith M. Wilson
	Name:	 	Keith M. Wilson
	Title:	 	Executive Vice President and Chief Financial Officer


  

			
	SM HOLDINGS, LLC
		
	By:	 	/s/ Keith M. Wilson
	Name:	 	Keith M. Wilson
	Title:	 	Executive Vice President and Chief Financial Officer