Exhibit 23.01 CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS As independent public accountants, we hereby consent to the incorporation of our reports incorporated by reference in or included in this Form 10-K, into the Company's previously filed Registration Statements File No. 333-36819, No. 333- 41355, No. 333-41357 and No. 333-67737. /s/ Arthur Andersen LLP Vienna, Virginia March 30, 2001