Ibasis SC 14D9 Tender offer solicitation

Exhibit (a)(56)

Customer Message Final (5:10 p.m.)

·iBasis Special Committee agrees to support KPN’s $3 per share tender offer for the 44% of iBasis shares that it does not already own, recommends that stockholders tender shares

·This is an exciting and positive development for iBasis customers:

·After successful completion of the transaction, iBasis will have the full support of KPN’s management and resources to execute on its business plan and strategies

·Until the transaction is completed we will continue to operate as an independent company until that time.

·Upon successful completion of the tender offer, iBasis CEO Ofer Gneezy, Executive VP Gordon VanderBrug and the iBasis Board of Directors, other than Eelco Blok and Joost Farwerck, will resign

·iBasis headquarters will remain in Burlington, Mass.

·iBasis and KPN agree to dismiss lawsuits in Delaware Chancery Court and U.S. District Court for the Southern District of New York

·Tender offer scheduled to expire at midnight on December 8, 2009 (KPN can extend twice for 10 business days each extension)