XO COMMUNICATIONS, LLC WAIVER WITH RESPECT TO AMENDED AND RESTATED CREDIT AND GUARANTY AGREEMENT

Exhibit 10.7

XO COMMUNICATIONS, LLC

WAIVER

WITH RESPECT TO

AMENDED AND RESTATED CREDIT AND GUARANTY AGREEMENT

     This Waiver ( “Waiver” ), dated as of May 7, 2007, with respect to the Amended and Restated Credit and Guaranty Agreement, dated January 16, 2003 (as amended, supplemented or otherwise modified, through the date hereof, and as it may be further amended, supplemented or otherwise modified, the “Credit Agreement” ), by and among XO Communications, LLC, a Delaware limited liability company (the “Company,” as successor by merger to XO Communications, Inc., a Delaware corporation), certain affiliates and subsidiaries of the Company, as Guarantors, the Lenders party thereto from time to time and Mizuho Corporate Bank, Ltd., as administrative agent (the “Administrative Agent” ).

RECITALS

     A.     Capitalized terms used herein without definition shall have the same meanings herein as set forth in the Credit Agreement.

     B.     Pursuant to Section 10.5 of the Credit Agreement, the Requisite Lenders have the right to waive any provision of the Credit Documents or consent to any departure of any Credit Party therefrom or may take any action contemplated in the Credit Documents and such waiver shall be effective upon the written concurrence of the Requisite Lenders.

     C.     The Lenders executing this Waiver constitute the Requisite Lenders pursuant to Section 1.1 of the Credit Agreement.

     D.     The Company anticipates that it will not be in compliance with Section 6.6(b) of the Credit Agreement for the fiscal quarter ended March 31, 2008.

     E.     The Requisite Lenders desire to waive compliance by the Company with the requirements of Section 6.6(b) of the Credit Agreement on the terms and for the periods set forth herein.

     NOW, THEREFOR