ARBX Arbinet Corp. (MM)

Arbinet Corporation (NASDAQ: ARBX) announces today that it has introduced a new Premium Mobile routing table for use by Arbinet Carrier Service (ACS) customers*. Premium Mobile is the highest quality routing table available on the ACS platform. Premium Mobile is designed for both fixed and mobile operators whose retail customers require advanced features and need the highest quality voice termination available. Arbinet Carrier Services features multiple levels of quality and Customer Based Routing(SM) where a customer can select from varied grades of service for each destination on a route-by-route basis over a single trunk group.

Key features and benefits of Arbinet's Premium Mobile termination include:

--  Direct termination to more than 250 Fixed and Mobile network operators

--  Guaranteed Caller Line Identity (CLI) transmission and delivery to
    terminating network suppliers

--  Support for Mobile Subscriber Roaming Number (MSRN) ranges

--  Release code management

--  Mobile Number Portability (MNP) & Local  Number Portability (LNP)
    support using the Arbinet Global Number Portability platform

--  Proactive testing & monitoring of Answer Seizure Ratio (ASR),
    Average Length of Call (ALOC) & Call Completion Ratio CCR

--  24x7 Multi-lingual premium Customer Care support

--  On-line Trouble Reporting

--  On-line Traffic Management & Quality of Service (QoS) Reporting

--  Prepaid support

Arbinet has been offering Premium Mobile routes since late 2009. CLI delivery and MSRN support enable operators to deliver a higher quality experience to their customers and to increase revenues through higher ARPU and reduced churn.

"At Digicel we take every effort to ensure the highest possible quality of service for our mobile subscribers and inbound roamers. Having access to high quality voice services with direct fixed and mobile termination, CLI delivery, and MSRN support helps to meet these increasingly complex demands. Arbinet's new Premium Mobile CLI solution provides us with the type of quality routing and voice termination required by our customers," commented Mario Rojas, Director Carrier Services at leading Caribbean and Central American mobile operator Digicel Group.

"In 2009, Arbinet increased the flexibility with which it works with the marketplace. We launched ACS, a traditional wholesale way of working with customers and suppliers. ACS features standard rate sheets, utilizes supplier codes and has no fees," said Brian Troesch, Sr. Vice President, Product & Business Development. "We made a concerted effort to drive away low-quality traffic from the network through the deployment of False Answer Supervision (FAS) identification protocols and technology. And we worked hard to identify the high quality direct termination routes from our 1100+ suppliers. With the addition of our Premium Mobile service, retail fixed and mobile operators now have a new choice to route their highest quality traffic flows."

Arbinet offers three ways for carriers and service providers to originate and terminate international voice traffic. Arbinet Carrier Services is a standard wholesale interface with no fees, a single invoice and rate lock. It uses supplier codes in its wholesale routing plans. PrivateExchange(SM) is an easy to use, low-risk outsourcing approach that enables service providers to create virtual direct routes and aggregate existing interconnects. thexchange™ is the industry's leading marketplace for buying and selling voice communications.

For more information about Arbinet please visit www.arbinet.com or e-mail sales@arbinet.com.

* All underlying CLI routes used in Arbinet's Premium Mobile table are available on thexchange.

About Arbinet

Arbinet is a leading provider of international voice and IP solutions to carriers and service providers globally. With more than 1100 carriers across the world connected to the Arbinet Network, Arbinet combines global scale with sophisticated platform intelligence, call routing and industry leading credit management and settlement capabilities. Customers and suppliers include many leading fixed line, mobile, wholesale and VoIP carriers as well as calling card, ISPs and content providers around the world who buy and sell voice and IP telecommunications capacity and content.

Forward-Looking Statements

This press release may contain forward-looking statements, including forward-looking statements regarding anticipated future revenues, growth, capital expenditures, management's future expansion plans, expected product and service developments or enhancements, discussions of strategy, and future operating results. Such forward-looking statements may be identified by, among other things, the use of forward-looking terminology such as: "believes," "expects," "intends," "may," "will," "should," "confident," "work to," "seeks," or "anticipates," or the negative thereof or other variations thereon or comparable terminology, or by discussions of strategy. Various risks and uncertainties may cause Arbinet's actual results to differ materially from those express or implied in such forward-looking statements. Please refer to Part I, Item 1A of the Company's Annual Report on Form 10-K, filed with the Securities and Exchange Commission on March 16, 2009, and other filings that have been filed with the Securities and Exchange Commission for a description of the risks and uncertainties that Arbinet faces. Arbinet assumes no obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise, and such statements are current only as of the date they are made.

Ilissa Miller Jaymie Scotto & Associates 1.866.695.3629 Email Contact Michelle Midura Arbinet 1.732.509.9235 Email Contact