Arbinet-thexchange (ARBX)

Consent of Independent Registered Public Accounting Firm

We consent to the incorporation by reference in the Arbinet-thexchange, Inc. Registration Statement (Form S-8 No. 333-125550), pertaining to the stock incentive plans of Arbinet-thexchange, Inc., of our reports dated March 14, 2008, with respect to the consolidated financial statements and schedule of Arbinet-thexchange, Inc., and the effectiveness of internal control over financial reporting of Arbinet-thexchange, Inc., included in this Form 10-K for the year ended December 31, 2007.

/s/ Ernst & Young LLP

Iselin, New Jersey

March 14, 2008

Consent of Independent Registered Public Accounting Firm

We consent to the incorporation by reference in the Arbinet-thexchange, Inc. Registration Statement (Form S-8 No. 333-125550), pertaining to the stock incentive plans of Arbinet-thexchange, Inc., of our reports dated March 15, 2007, with respect to the consolidated financial statements and schedules of Arbinet-thexchange, Inc., and management’s assessment of the effectiveness of internal control over financial reporting and the effectiveness of internal control over financial reporting of Arbinet-thexchange, Inc., included in this Annual Report (Form 10-K) for the year ended December 31, 2006.

MetroPark, New Jersey

March 15, 2007