EXHIBIT 23.1
CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS
As independent public accountants, we hereby consent to the incorporation by reference in this Form 10-K of our report dated February 6, 2002. It should be noted that we have not audited any financial statements of XO Communications, Inc. subsequent to December 31, 2001, or performed any audit procedures subsequent to the date of our report.
| FILE NUMBER | FILE DESCRIPTION | |
| 333-39414 | Form S-8 regarding the Company’s Stock-Related Benefit Plans | |
| 333-48684 | Form S-8 regarding the Company’s Cash Compensation Deferral Plan | |
| 333-54790 | Form S-3 regarding the Company’s Universal Shelf Registration Statement | |
| 333-34974 | Post-Effective Amendment No. 1 on Form S-3 to Registration Statement on Form S-4 regarding shares of the Company’s Class A common stock issuable upon exercise of warrants assumed in connection with the merger with Concentric Network Corporation | |
| 333-67896 | Form S-3 Amendment No. 1 regarding the Company’s 5 ¾% convertible subordinated notes and underlying shares of Class A common stock into which the notes are convertible |
| Vienna, VA March 28, 2002 | /s/ ARTHUR ANDERSEN LLP |
