EX-23.1 6 0006.txt CONSENT OF ARTHUR ANDERSEN LLP Consent of Independent Public Accountants As independent public accountants, we hereby consent to the incorporation of our reports in this Form 10-K, into the Company's previously filed Registration Statement File Nos. 35-27317, 33-21698, 33-06183, 333-49779, and 333-62037. ARTHUR ANDERSEN LLP Vienna, VA September 15, 2000