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Exhibit 10.57    
    


 
 

JOINDER AGREEMENT    
    


        Reference is hereby made to the Securities Exchange Agreement dated as of February 21, 2003 (the "Exchange
Agreement"), by and between the iBasis, Inc. (the "Company"), iBasis Global, Inc.
("Global" and, together with the Company, the "Borrower"), iBasis Securities Corporation, JMG Triton
Offshore Fund Limited CITCO and the other Exchanging Holders named therein, and U.S. Bank National Association, as Collateral Agent, Fiscal Agent and Warrant Agent (the
"Agent"). Capitalized terms used herein and not otherwise defined shall have the meanings assigned to such terms in the Exchange Agreement. 


        Pursuant
to the terms and conditions of the Exchange Agreement, the Borrower, the Agent and the persons set forth on Annex A hereto (the "Acceding
Holders" and each, individually, an "Acceding Holder") and each person that becomes an Acceding Holder to this Joinder Agreement
pursuant to Section 9 hereof hereby agree as follows: 


        SECTION 1.    Subject to the terms and conditions of this Joinder Agreement, dated as of May 29, 2003 (this
"Joinder Agreement"), each Acceding Holder hereby agrees to exchange, on or as of the Effective Date (as defined below), Convertible Notes in the
aggregate principal amount set forth opposite such Acceding Holder's name on Annex A hereto for (a) the aggregate principal amount set
forth opposite such Acceding Holder's name on Annex A hereto of the Borrower's 11.5% Senior Secured Notes due 2005 and (b) Warrants
exercisable for an aggregate number of shares of Common Stock set forth opposite such Acceding Holder's name on Annex A hereto, all in accordance
with the terms and conditions set forth in the Exchange Agreement. Each Acceding Holder hereby agrees to be bound by, and hereby requests the agreement of the Borrower and the Agent that such Acceding
Holder shall be entitled to the benefits of, all of the terms, conditions and provisions of the Exchange Agreement as if such Acceding Holder had been one of the Persons originally executing the
Exchange Agreement as an "Exchanging Holder"; provided that nothing herein shall be construed as making such Acceding Holder liable to the Borrower or
the other Exchanging Holders or the Borrower liable to such Acceding Holder in respect of any acts or omissions of any party to the Exchange Agreement or in respect of any other event occurring prior
to the Effective Date (as defined below) of this Joinder Agreement. Furthermore, each Acceding Holder expressly acknowledges and agrees that by executing and delivering this Joinder Agreement
(i) it becomes a party to the Exchange Agreement, the Intercreditor Agreement and the Subordination Agreement, in each case as an "Exchanging Holder", (ii) it accepts and shall be
subject to the terms of the Fiscal Agency Agreement and the Warrant Agreement as a Noteholder and
a Warrantholder, respectively, and (iii) it accepts and shall be subject to the terms of each of the Credit Documents as an Exchanging Holder, as the same may be applicable. 


        SECTION 2.    (a) Each Acceding Holder, subject to Section 2(b) below, severally, but not jointly with any other Acceding
Holder, (i) represents and warrants that (A) it is duly and legally authorized to enter into this Joinder Agreement, (B) the execution, delivery and performance of this Joinder
Agreement do not conflict with any provision of law or, if such Acceding Holder is not an individual, of the charter or by-laws of such Acceding Holder, or of any agreement binding on such
Acceding Holder, and (C) all acts, conditions and things required to be done and performed and to have occurred prior to the execution, delivery and performance of this Joinder Agreement, and
to render the same the legal, valid and binding obligation of such Acceding Holder, enforceable against it in accordance with its terms, have been done and performed and have occurred in due and
strict compliance with all applicable laws; (ii) confirms that it has received a copy of the Exchange Agreement, together with such other documents and information as it has deemed appropriate
to make its own credit analysis and decision to enter into this Joinder Agreement; (iii) agrees that it will, independently and without reliance upon the Exchanging Holders or the Agent and
based on such documents and information as it shall deem appropriate at the time, continue to make its own credit decisions in taking or not taking action under the Exchange Agreement;
(iv) appoints and authorizes the Agent to take such action as 





 



agent
on its behalf and to exercise such powers under the Exchange Agreement and the other Loan Documents as are delegated to the Agent by the terms thereof, together with such powers as are
reasonably incidental thereto; and (v) agrees that it will perform in accordance with their terms all of the obligations which by the terms of the Exchange Agreement are required to be
performed by it as an Exchanging Holder. 


        (b)
Each Acceding Holder, severally, but not jointly with any other Acceding Holder, represents and warrants only as to itself that, except as set forth on  Schedule 2 attached hereto, it is an
"accredited investor" as that term is defined in Rule 501 of Regulation D promulgated under
the Securities Act, by virtue, inter alia, of its being (i) a corporation, Massachusetts or similar business trust, or partnership, not formed
for the specific purpose of acquiring the Warrants or the shares of Common Stock issuable upon exercise of the Warrants, with total assets in excess of $5,000,000, (ii) a natural person whose
individual net worth, or joint net worth with that person's spouse, at the time of his or her exchange exceeds $1,000,000, or (iii) a natural person who had an individual income in excess of
$200,000 in each of the two most recent years or joint income with that person's spouse in excess of $300,000 in each of those years and has a reasonable expectation of reaching the same income level
in the current year. The Company hereby waives the accredited investor representation set forth in Section 8.5 of the Exchange Agreement for those Acceding Holders set forth on  Schedule 2.




        SECTION 3.    The Acceding Holders hereby request that the Borrower issue a new global note increasing the principal amount by
$6,100,000 and a new global warrant increasing the number of shares
exercisable thereunder by an aggregate of 1,116,605 shares of Common Stock; and the Company hereby authorizes and directs the Agent to authenticate and register, in the names and denominations
specified herein, and to deliver each such Global Security, when so authenticated and registered, to The Depository Trust Company, or its custodian, on the Effective Date (as defined below). 


        SECTION 4.    The effective date for this Joinder Agreement shall be May 29, 2003 (the "Effective
Date"). Following the execution of this Joinder Agreement by the Borrower and the Acceding Holders, it will be delivered to the Agent for acceptance. 


        SECTION 5.    By execution of this Joinder Agreement, the Borrower hereby certifies that: (i) the sum of the aggregate
original principal amount of the Notes to be issued pursuant to this Joinder Agreement, together with the aggregate original principal amount of all other Notes previously issued under the Fiscal
Agency Agreement, does not exceed $28,750,000; (ii) the sum of the aggregate amount of Warrant Shares issuable upon exercise of the Warrants to be issued pursuant to this Joinder Agreement,
together with the aggregate amount of Warrant Shares issuable (or, if exercised, issued) upon exercise of all Warrants previously issued pursuant to any and all other Joinder Agreements entered into
pursuant to (and after the date of) the Exchange Agreement (which, for avoidance of doubt, does not include any Warrants issued to the Exchanger, as that term is defined in and pursuant to the
Exchange Agreement, or any Warrants issued pursuant to the Symphony Exchange Agreement) does not exceed 1,967,798; and (iii) this Joinder Agreement, and the Notes and Warrants to be issued
pursuant thereto, constitutes a Permitted Exchange in accordance with Section 9.3 of, and otherwise is in accordance with, the Exchange Agreement. 



        SECTION 6.    THIS JOINDER AGREEMENT SHALL FOR ALL PURPOSES BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE
WITH, THE LAWS OF THE COMMONWEALTH OF MASSACHUSETTS (WITHOUT REGARD TO THE PRINCIPLES OF CONFLICTS OF LAWS).


        SECTION 7.    The use in this Joinder Agreement of neuter pronouns in reference to a party hereto shall be deemed to include the
masculine or feminine, as the context may require. 



        SECTION 8.    This Joinder Agreement may be executed in any number of counterparts which shall together constitute but one and
the same agreement. This Joinder Agreement, once duly executed 


2





 



and
delivered in accordance with the terms of the Exchange Agreement, may be relied upon conclusively by the Agent. 


        SECTION 9.    Any person that is a holder of Convertible Notes may become an Acceding Holder party to this Joinder Agreement by
executing and delivering to the Borrower and the Agent, on or prior to June 30, 2003, an Instrument of Accession, substantially in the form of Annex
B attached hereto,
provided that the Borrower and the Agent consent to such person becoming an Acceding Holder party to this Joinder Agreement (which consent shall be conclusively deemed to have been given by the
Borrower and Agent when each countersigns the Instrument of Accession executed by such person). Any such Instrument of Accession executed by any such person and countersigned by the Borrower and Agent
shall become a part of this Joinder Agreement. It is hereby understood and agreed that each of Annex A and  Schedule 2 shall be updated to reflect
such Acceding Holder's interest. Any exchange of Convertible Notes for Notes by a holder of Convertible
Notes who becomes an Acceding Party to this Joinder Agreement shall be deemed to have occurred for all purposes of this Joinder Agreement and such Convertible Notes as of the Effective Date,
regardless of the date on which exchange may actually be consummated. 


[Remainder
of Page Intentionally Left Blank] 


3








        IN WITNESS WHEREOF, intending to be legally bound, each of the undersigned has caused this Joinder Agreement to be executed on its behalf
by its officer thereunto duly authorized, to take effect as a sealed instrument as of the date first above written. 



	 	 	iBASIS, INC.
	

 	
 	

By:	

/s/  OFER GNEEZY      
 Name:  Ofer Gneezy

Title:    President and CEO
	
 	
 	

iBASIS GLOBAL, INC.
	

 	
 	

By:	

/s/  RICHARD TENNANT      
 Name:  Richard Tennant

Title:    Treasurer & CFO





	
 	
 	
ACCEDING HOLDERS

listed on Annex A hereto
	

 	
 	
By:	
 	

COMMONWEALTH ADVISORS, INC.

their attorney in fact
	

 	
 	

 	
 	

By	

/s/  WALTER MORALES      
 Name:      Walter Morales

Title:        President

Address:  P.O. Box 3395

                 Baton Rouge, LA 70821





	Acknowledged this 29 day of May, 2003:	 
	
U.S. BANK NATIONAL ASSOCIATION,

as Collateral Agent under the Securities Exchange Agreement.	

 
	

By:	

/s/  JOHN BRENNAN      
 Name:  John Brennan

Title:    Trust Officer	

 









 
 

Annex A    
    



	Name of Acceding Holder
 
	 	Principal Amount of exchanged Convertible Notes
	 	Principal Amount of new Notes
	 	Number of Shares into which Warrants are exercisable

	Ferguson, William & Janiece B.	 	 	70,000	 	 	35000	 	6407
	Anepohl, Clarilynn D.	 	 	45,000	 	 	22000	 	4119
	Breaux, Frank W.	 	 	100,000	 	 	50000	 	9153
	Anepohl, Jr., Fred G.	 	 	35,000	 	 	18000	 	3203
	Solar, Curtis J & Kay M	 	 	20,000	 	 	10000	 	1831
	Attrep, John	 	 	90,000	 	 	45000	 	8237
	Balcom, Grace, Randy & Carolyn	 	 	75,000	 	 	37000	 	6864
	Ballard, E. Dwight	 	 	70,000	 	 	35000	 	6407
	Ballard, Dwight & Sandra Jean	 	 	20,000	 	 	10000	 	1831
	Balle, David S	 	 	35,000	 	 	18000	 	3203
	Balliro, Peggy G	 	 	20,000	 	 	10000	 	1831
	Williams, John Kelly	 	 	50,000	 	 	25000	 	4576
	Bayard, William J	 	 	25,000	 	 	13000	 	2288
	Anjier, Joseph L	 	 	90,000	 	 	45000	 	8237
	Bombet MD, Leon H	 	 	100,000	 	 	50000	 	9153
	Borak, Rachel	 	 	35,000	 	 	18000	 	3203
	Brewer, Ralph	 	 	65,000	 	 	32000	 	5949
	Bowman, Edwin A	 	 	35,000	 	 	18000	 	3203
	Burroughs MD, Richard	 	 	175,000	 	 	87000	 	16017
	Hirsch, Gary S. & Karen E	 	 	75,000	 	 	37000	 	6864
	Hirsch, Gary S	 	 	130,000	 	 	65000	 	11898
	Weldon, William E	 	 	170,000	 	 	85000	 	15559
	Weldon, William & Cornelia	 	 	115,000	 	 	57000	 	10525
	Newcomer, JR, George C	 	 	90,000	 	 	45000	 	8237
	Cassidy, Laura	 	 	40,000	 	 	20000	 	3661
	Pace, William Robert	 	 	70,000	 	 	35000	 	6407
	CJS Investments	 	 	25,000	 	 	13000	 	2288
	Claiborne, Earl B.	 	 	110,000	 	 	55000	 	10068
	Claiborne, Earl B. & Ethel L.	 	 	25,000	 	 	13000	 	2288
	Head & Neck P/S Plan, Clinic of	 	 	30,000	 	 	15000	 	2746
	Head & Neck Pension Pln, Clinic	 	 	65,000	 	 	32000	 	5949
	Collins, Steven & Eileen	 	 	30,000	 	 	15000	 	2746
	De Fraites, Rebecca Kay	 	 	20,000	 	 	10000	 	1831
	de Jongh, Maria P	 	 	20,000	 	 	10000	 	1831
	De Fraites JR, Emanuel G	 	 	50,000	 	 	25000	 	4576
	de Jongh, Alberto & Maria	 	 	160,000	 	 	80000	 	14644
	Delhaye Children's Tr II	 	 	65,000	 	 	33000	 	5949
	Mayfield, Mary Jo	 	 	115,000	 	 	57000	 	10525
	Dement, Leon D. & Sylvia L.	 	 	75,000	 	 	37000	 	6864
	Delhaye, Mary Field	 	 	25,000	 	 	13000	 	2288
	Dupont, J. Benton	 	 	115,000	 	 	57000	 	10525
	Dupont MD, J. Benton	 	 	30,000	 	 	15000	 	2746
	Dyer, Herbert R.	 	 	180,000	 	 	90000	 	16475
	Phillips, Gary N	 	 	210,000	 	 	105000	 	19220
	Silverberg, Joel D	 	 	25,000	 	 	13000	 	2288
	Trahan III, Victor "Trey"	 	 	130,000	 	 	65000	 	11898
	Barry, Mary Kathleen V	 	 	200,000	 	 	100000	 	18305
	Cloud, Louise C	 	 	60,000	 	 	30000	 	5492







	Fazio, Frank L	 	 	45,000	 	 	23000	 	4119
	Ferguson, William F	 	 	50,000	 	 	25000	 	4576
	Mayfield FP, Field	 	 	65,000	 	 	32000	 	5949
	Sanders, Donald Leroy	 	 	75,000	 	 	37000	 	6864
	Fleury, JR, Linton Albert	 	 	55,000	 	 	27000	 	5034
	Gasparrini, Sue D	 	 	25,000	 	 	13000	 	2288
	Gasparrini, William G	 	 	65,000	 	 	32000	 	5949
	Mayfield, Drew Generation Skippi	 	 	10,000	 	 	5000	 	915
	Greco, Leu Anne	 	 	50,000	 	 	25000	 	4576
	Greco TTEE, Cyrus John	 	 	100,000	 	 	50000	 	9153
	Grissom MD, Robert T	 	 	25,000	 	 	13000	 	2288
	Grissom MD, Robert T	 	 	15,000	 	 	8000	 	1373
	Greco, Cyrus John	 	 	120,000	 	 	60000	 	10983
	Haga, D Bruce	 	 	25,000	 	 	13000	 	2288
	Hall MD, Donald Leroy	 	 	110,000	 	 	55000	 	10068
	Kennon JR, Robert F	 	 	70,000	 	 	35000	 	6407
	Harner, James Oliver	 	 	70,000	 	 	35000	 	6407
	Hirsch, Karen Elkind	 	 	30,000	 	 	15000	 	2746
	Haydel, Froisin J.	 	 	220,000	 	 	110000	 	20127
	Haydel, F. Joseph & Frances L.	 	 	50,000	 	 	25000	 	4576
	Mayfield Trust, John D.	 	 	25,000	 	 	13000	 	2288
	Bayard, William J & Peggy G	 	 	30,000	 	 	15000	 	2746
	Bayard, William J & Peggy G	 	 	15,000	 	 	8000	 	1373
	Norman, Joseph R.	 	 	95,000	 	 	47000	 	8695
	Norman, Joseph R. & Susan	 	 	15,000	 	 	8000	 	1373
	BCL Investment Partnership	 	 	90,000	 	 	45000	 	8237
	Kirsch JR, William G	 	 	40,000	 	 	20000	 	3661
	Herad, Khosrow	 	 	55,000	 	 	27000	 	5034
	Trahan III "Trey", Victor F	 	 	10,000	 	 	5000	 	915
	Laville, Anne	 	 	50,000	 	 	25000	 	4576
	Laville, Anne M.	 	 	40,000	 	 	20000	 	3661
	Lee, David M	 	 	40,000	 	 	20000	 	3661
	Lee, J. David	 	 	100,000	 	 	50000	 	9153
	Lockwood, Thomas M.	 	 	25,000	 	 	13000	 	2288
	La. Realtors Assoc LDF	 	 	50,000	 	 	25000	 	4576
	Delhaye Trust, Mary Jo	 	 	10,000	 	 	5000	 	915
	Maestri Jr., Natale A	 	 	25,000	 	 	13000	 	2288
	Mayfield, Lucy R	 	 	40,000	 	 	20000	 	3661
	Mayfield, Mary Jane	 	 	95,000	 	 	47000	 	8695
	Cloyd, William P.	 	 	110,000	 	 	55000	 	10068
	McMillin, Bill	 	 	70,000	 	 	35000	 	6407
	McNeil, Edwin B	 	 	50,000	 	 	25000	 	4576
	Mosley, Guy J & Wanda M	 	 	60,000	 	 	30000	 	5492
	Mosley, Guy J	 	 	30,000	 	 	15000	 	2746
	Mosley, Wanda M	 	 	40,000	 	 	20000	 	3661
	Myres, Betty G	 	 	50,000	 	 	25000	 	4576
	Myres, Yancey C	 	 	45,000	 	 	22000	 	4119
	Shannon, Keith D	 	 	40,000	 	 	20000	 	3661
	Noland, Ameila M	 	 	50,000	 	 	25000	 	4576
	Ordeneaux, Jerry C.	 	 	140,000	 	 	70000	 	12814







	Poche, Francis Jay	 	 	15,000	 	 	8000	 	1373
	Pollard, Glenda S	 	 	65,000	 	 	32000	 	5949
	Reine MD, Georgia A	 	 	20,000	 	 	10000	 	1831
	Reine, Georgia A	 	 	175,000	 	 	87000	 	16017
	Richey, Anne Q	 	 	70,000	 	 	35000	 	6407
	Richey, Charles A	 	 	70,000	 	 	35000	 	6407
	Richey, Charles A & Anne Q	 	 	60,000	 	 	30000	 	5492
	Coleman & Partners, Robert	 	 	100,000	 	 	50000	 	9153
	Russo III DDS, Camille Joseph	 	 	60,000	 	 	30000	 	5492
	Russo, Camille J & Patricia	 	 	50,000	 	 	25000	 	4576
	Russo III DDS MPP, Camille J	 	 	90,000	 	 	45000	 	8237
	Rucci, Peter J	 	 	40,000	 	 	20000	 	3661
	Schexnayder, Michael C. & Charl	 	 	25,000	 	 	13000	 	2288
	Schexnayder MD, Michael C.	 	 	60,000	 	 	30000	 	5492
	Schucker, Robert Charles	 	 	170,000	 	 	85000	 	15559
	Schwartzberg, Harvey J	 	 	70,000	 	 	35000	 	6407
	Schwartzberg, Harvey J & Betty	 	 	25,000	 	 	13000	 	2288
	Schwartzberg, Ellis J. & Barb	 	 	55,000	 	 	27000	 	5034
	Shannon, Maureen G	 	 	50,000	 	 	25000	 	4576
	Drake, Kathryn M	 	 	15,000	 	 	8000	 	1373
	Cloyd MD, William P.	 	 	210,000	 	 	105000	 	19220
	Solar, Karen Kay	 	 	30,000	 	 	15000	 	2746
	Mayfield Trust, Lucy R.	 	 	25,000	 	 	12000	 	2288
	Steen, Gayle	 	 	175,000	 	 	87000	 	16017
	Collins TTEE, Steven D	 	 	50,000	 	 	25000	 	4576
	Stark, Michael M	 	 	80,000	 	 	40000	 	7322
	Wood, Danny S.	 	 	15,000	 	 	8000	 	1373
	Cavalier, MD, Steven J.	 	 	110,000	 	 	55000	 	10068
	Alvarez, MD, Frank J.	 	 	100,000	 	 	50000	 	9153
	Schwartzberg, MD, Glen	 	 	85,000	 	 	42000	 	7780
	Robin, MD, Richard L.	 	 	140,000	 	 	70000	 	12814
	Roberts, MD, Floyd J.	 	 	165,000	 	 	82000	 	15102
	Melker MD, Merritt "Trey"	 	 	100,000	 	 	50000	 	9153
	Dement, MD, Leon N.	 	 	190,000	 	 	95000	 	17390
	Gladney, MD, William W.	 	 	100,000	 	 	50000	 	9153
	Peairs, MD, Patricia T.	 	 	35,000	 	 	18000	 	3203
	Hargus, MD, Louis Field	 	 	125,000	 	 	62000	 	11441
	Waggenspack, MD, Mark	 	 	70,000	 	 	35000	 	6407
	Silverberg, MD, Joel	 	 	25,000	 	 	13000	 	2288
	Rolfsen, MD, Michael	 	 	80,000	 	 	40000	 	7322
	Seiter, MD, Elizabeth D.	 	 	90,000	 	 	45000	 	8237
	Vicari, MD, Roberta C.	 	 	50,000	 	 	25000	 	4576
	Vath, MD, Richard R.	 	 	105,000	 	 	52000	 	9610
	Silvey, Edgar H.	 	 	80,000	 	 	40000	 	7322
	Hecker MD, Roger	 	 	35,000	 	 	17000	 	3203
	Earhart MD, Robert N	 	 	115,000	 	 	57000	 	10525
	Vinci, MD, Edmund	 	 	60,000	 	 	30000	 	5492
	Fraser, MD, Warren M.	 	 	125,000	 	 	62000	 	11441
	Thudium, Jr., John F.	 	 	165,000	 	 	82000	 	15102
	Barry, Mary Kathleen	 	 	35,000	 	 	18000	 	3203







	Garcia, O J	 	 	65,000	 	 	32000	 	5949
	Waguespack, Hubert J.	 	 	140,000	 	 	70000	 	12814
	Waguespack, Phillip J.	 	 	100,000	 	 	50000	 	9153
	Wall IV, Williams D	 	 	45,000	 	 	23000	 	4119
	Wall IV, Williams D	 	 	30,000	 	 	15000	 	2746
	Walsh, Robert Eugene	 	 	20,000	 	 	10000	 	1831
	Walsh, Robert & Linda	 	 	50,000	 	 	25000	 	4576
	Williams, John Kelly	 	 	80,000	 	 	40000	 	7322
	Wood, Danny S. & Leah S.	 	 	25,000	 	 	13000	 	2288
	Wood, MD, Danny S.	 	 	110,000	 	 	55000	 	10068
	Bernhard, Jo'An O	 	 	40,000	 	 	20000	 	3661
	Zuckerman, Steven J.	 	 	50,000	 	 	25000	 	4576
	Zuckerman, Steven & Marialden	 	 	45,000	 	 	23000	 	4119
	Allen, Lane	 	 	65,000	 	 	33000	 	5949
	Ashford, Jules	 	 	110,000	 	 	55000	 	10068
	Bradford, Juanita	 	 	75,000	 	 	37000	 	6864
	Ellison, Linda	 	 	50,000	 	 	25000	 	4576
	Gust, Dorothy	 	 	10,000	 	 	5000	 	915
	Gust, Richard	 	 	65,000	 	 	32000	 	5949
	Salter, Barbara	 	 	45,000	 	 	23000	 	4119
	Summers, Steven	 	 	30,000	 	 	15000	 	2746
	Summers, Jane	 	 	10,000	 	 	5000	 	915
	Summers, S & J	 	 	35,000	 	 	17000	 	3203
	

TOTAL:	
 	
$	

11,770,000	
 	
$	

5,884,000	
 	

1,077,248
	

Additional New Notes and Warrants to be held by iBasis until such time as additional Acceding Holders become party to this Joinder Agreement pursuant to Section 9 hereof.	
 	
$
	

430,000

—To be exchanged.	
 	
$	

216,000	
 	

39,357
	
TOTAL:	
 	
 	
12,200,000	
 	
$	

6,100,000	
 	

1,116,605









 
 

Schedule 2    
    


 
 

Schedule of Exceptions    
    



	Name of

Acceding Holder
	 	Principal Amount

of exchanged

Convertible Notes
	 	Principal Amount

of new Notes
	 	Number of Shares

into which Warrants

are exercisable

	Allen, Lane	 	65,000	 	33,000	 	5,949
	Ashford, Jules	 	110,000	 	55,000	 	10,068
	Bradford, Juanita	 	75,000	 	37,000	 	6,864
	Ellison, Linda S	 	50,000	 	25,000	 	4,576
	Gust, Dorothy B	 	10,000	 	5,000	 	915
	Gust, Richard	 	65,000	 	32,000	 	5,949
	Salter, Barbara G	 	45,000	 	23,000	 	4,119
	Summers, Steven Hall	 	30,000	 	15,000	 	2,746
	Summers, Jane Kay	 	10,000	 	5,000	 	915
	Summers, Steven & Jane K	 	35,000	 	17,000	 	3,203









 
 

Annex B    
    


 
 

Instrument of Accession    
    


 
 

[June    , 2003]    
    


        Reference is made to that certain Joinder Agreement dated as of May 29, 2003, a copy of which is attached hereto (as amended and in effect from time to
time, the "Joinder Agreement"), among iBasis, Inc. (the "Company"), iBasis Global, Inc.
("Global" and together with the Company, the "Borrower"), the Acceding Holders as named therein, and U.S. Bank National Association, as Collateral
Agent, Fiscal Agent and Warrant Agent (the "Agent"). 


        The
persons listed on Schedule 1 attached hereto are the owners or holders of the Company's 53/4% Convertible
Subordinated Notes due 2005 and each person hereby agrees that, by his or her execution hereof, that it is an Acceding Holder party to the Joinder Agreement and that he or she is subject to all of the
restrictions and conditions applicable to the Acceding Holders set forth in such Joinder Agreement. This Instrument of Accession shall take effect and shall become a part of said Joinder Agreement
immediately upon acceptance thereof by the Borrower and the Agent. Attached hereto are revised Annex A and  Schedule 2 to the Joinder Agreement.



        Executed
as of the date set forth below under the laws of the Commonwealth of Massachusetts. 



	

 	
 	
ACCEDING HOLDERS

listed on Schedule 1 hereto
	

 	
 	

By:	

COMMONWEALTH ADVISORS, INC.

their attorney in fact
	

 	
 	

By:	

 Name:

Title:

Address;    P.O. Box 3395

                   Baton Rouge, LA 70821





	

Accepted:
 iBASIS, INC.	

 
	
By:	

 Name:

Title:	

 









	iBASIS GLOBAL, INC.	 
	
By:	

 Name:

Title:	

 
	
U.S. BANK NATIONAL ASSOCIATION,

as Collateral Agent under the Securities Exchange Agreement.	

 
	

By:	

 Name:

Title:	

 









 
 

Schedule 1    
    



	Name of

Acceding Holder
	 	Principal Amount

of exchanged

Convertible Notes
	 	Principal Amount

of new Notes
	 	Number of Shares

into which Warrants

are exercisable






[List
the Acceding Holders that are additional parties to the Joinder Agreement pursuant to Section 9 thereof.] 









QuickLinks



Exhibit 10.57


JOINDER AGREEMENT



Annex A




Schedule 2


Schedule of Exceptions



Annex B


Instrument of Accession

[June , 2003]




Schedule 1