Exhibit 10.1

           THIS NOTE HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT

              OF 1933 AND MAY NOT BE SOLD, TRANSFERRED OR OTHERWISE

                  DISPOSED OF UNLESS REGISTERED UNDER THAT ACT

                 OR AN EXEMPTION FROM REGISTRATION IS AVAILABLE.

                                 IFX CORPORATION

                           CONVERTIBLE PROMISSORY NOTE

$2,755,000.00                                            Dated: October 31, 2002

          FOR VALUE RECEIVED IFX CORPORATION, a Delaware corporation (the
"Company"), hereby promises to pay to UBS Capital Americas III, L.P., a limited
partnership formed under the laws of Jersey, Channel Islands (the "Payee"), or
its registered assigns, the principal amount of Two Million Seven Hundred
Fifty-five Thousand and 00/100 Dollars ($2,755,000.00 ) together with interest
thereon calculated from the date hereof in accordance with the provisions of
this Convertible Promissory Note (the "Convertible Note").

          Certain capitalized terms are defined in Section 8 hereof.

          1. Interest Rate. Interest shall accrue at a rate equal to ten percent
(10%) per annum (the "Interest Rate") on the unpaid principal amount of this
Convertible Note outstanding from time to time; provided that so long as any
Event of Default has occurred and is continuing, interest shall accrue to the
extent permitted by law at the rate of the Interest Rate plus two percent (2%)
per annum on the unpaid principal amount of this Convertible Note outstanding
from time to time for the period beginning on the date on which such Event of
Default occurs and ending on the date on which such Event of Default ceases to
exist. Interest shall be computed on the basis of the actual number of days
elapsed and a 360-day year.

          2. Maturity Date. Notwithstanding Section 3 below, the entire
principal amount of this Convertible Note and all accrued but unpaid interest
thereon shall be due and payable in full in cash in immediately available funds
on September 30, 2007 (the "Maturity Date"). Any overdue principal and overdue
interest together with any interest thereon, shall be due and payable upon
demand.

          3. Conversion.

          (a) Subject to a Forced Payee D Election described below, at the
election of the Payee (the "Payee D Election") at any time prior to the Maturity
Date, all of the principal amount of this Convertible Note plus accrued and
unpaid interest thereon may be converted into shares of the Series D Preferred
Stock at a conversion price equal to $1.20 per share (as adjusted for stock
splits, combinations, stock dividends and the like) of Series D Preferred Stock
(the



"Series D Conversion Price"). The Series D Preferred Stock to be issued upon any
such conversion shall have the same rights, preferences and privileges as the
shares of the Series D Preferred Stock issued in the Series D Financing. The
Payee, upon making such conversion, and as a condition thereof, shall enter into
a registration rights agreement and shareholders agreement substantially in the
form of the Third Amended and Restated Registration Rights Agreement and the
Fourth Amended and Restated Stockholders Agreement among the Company and the
holders of the Series D Preferred Stock, if the Payee is not already a party to
any of such agreements. No fractional shares shall be issued upon a conversion
into Series D Preferred Stock. In lieu of any fractional shares to which Payee
would otherwise be entitled, the Company shall pay cash equal to such fraction
multiplied by the Series D Conversion Price. In the event that the Payee does
not own Company Common Stock at the time of the conversion to Series D Preferred
Stock pursuant to this section, then in lieu of the "common to preferred"
conversion right provided under the terms of the Series D Financing, and in
addition to the shares of Series D Preferred Stock issuable as provided above,
Payee shall receive 0.0342 shares of Series D Preferred Stock for each dollar of
Convertible Note plus accrued and unpaid interest converted pursuant hereto. In
the event that Convertible Noteholders holding a majority of the outstanding
principal amount of the Convertible Notes elect to make a Payee D Election, then
all of the Convertible Noteholders who have not otherwise voluntarily made a
Payee D Election shall be deemed to have automatically made a Payee D Election
on the first date that a majority of Convertible Noteholders holding a majority
of the Convertible Notes shall have made a Payee D Election (the "Forced Payee D
Election").

          (b) In the event that the Company enters into a Qualified Financing
Purchase Agreement prior to the Maturity Date (the date thereof being the
"Qualified Financing Date"), then, subject to a Forced Payee F Election
described below, at the election of the Payee (the "Payee F Election"), this
Convertible Note plus accrued and unpaid interest thereon may be converted, in
whole and not in part, into Qualified Financing Securities at a conversion price
equal to the purchase price per Qualified Financing Security set forth in the
Qualified Financing Purchase Agreement (the "Qualified Financing Conversion
Price"). The Company shall provide Payee timely notice of the Qualified
Financing Date, and Payee shall make the Payee F Election within ten (10)
business days of receiving such notice. The Payee, upon making such conversion,
and as a condition thereof, shall enter into any registration rights agreement,
shareholders agreement or other material agreements entered into by other
investors in the Qualified Financing. In the event that Convertible Noteholders
holding a majority of the outstanding principal amount of the Convertible Notes
elect to make a Payee F Election, then all of the Convertible Noteholders who
have not otherwise voluntarily made a Payee F Election shall be deemed to have
automatically made a Payee F Election on the first date that a majority of
Convertible Noteholders holding a majority of the Convertible Notes shall have
made a Payee F Election (the "Forced Payee F Election").

          (c) At such time as a conversion under this Section 3 has been
effected, the rights of the holder of this Convertible Note as the holder of
such note shall cease, and the Person or Persons in whose name or names any
certificate or certificates for shares of the Series D Preferred Stock or
Qualified Financing Securities, as the case may be, are to be issued upon such
conversion shall be deemed to have become the holder or holders of record of the
shares of such Series D Preferred Stock or Qualified Financing Securities
represented thereby.

                                  Page 2 of 11



          (d) The Company shall deliver to the converting holder a certificate
or certificates representing the number of shares of Series D Preferred Stock or
Qualified Financing Securities, as the case may be, issuable by reason of such
conversion in such name or names and such denomination or denominations as the
converting holder has specified.

          (e) The issuance of certificates for shares of Series D Preferred
Stock or Qualified Financing Securities, as the case may be, upon conversion of
this Convertible Note shall be made without charge to the holder hereof for any
issuance tax in respect thereof or other cost incurred by the Company in
connection with such conversion and the related issuance of shares of Series D
Preferred Stock or Qualified Financing Securities, provided that such holder
shall pay any transfer taxes associated therewith.

          (f) The Company shall at all times reserve and keep available out of
its authorized but unissued shares of Series D Preferred Stock or Qualified
Financing Securities, as the case may be, solely for the purpose of issuance
upon conversion hereunder, such number of shares of Series D Preferred Stock or
Qualified Financing Securities issuable upon conversion, or, if an adequate
number of shares of Series D Preferred Stock or Qualified Financing Securities
have not previously been authorized, the Company shall authorize additional
shares of Series D Preferred Stock or Qualified Financing Securities The Company
shall not designate or authorize any additional classes of Preferred Stock if
such authorization or designation would preclude the Company from authorizing
and issuing the Series D Preferred Stock or the Qualified Financing Securities.
All such securities which are so issuable shall, when issued, be duly and
validly issued, fully paid and nonassessable and free from all taxes, liens and
charges (other than the applicable shareholders agreement and securities laws).
The Company shall take all such actions as may be necessary to assure that all
such securities may be so issued without violation of any applicable law or
governmental regulation or any requirements of any domestic securities exchange
upon which such shares of capital stock may be listed; provided, that in no
event will the Company be obligated to register Series D Preferred Stock or
Qualified Financing Securities under the Securities Act of 1933.

          (g) Capital Stock

               (i) On the date hereof, the authorized capital stock of the
Company consists of (1) 110,000,000 shares of Common Stock, of which 11,963,399
shares of Common Stock are issued and outstanding, and (2) 40,000,000 shares of
Preferred Stock, of which (w) 2,030,869 shares of Preferred Stock have been
designated as Series A Convertible Preferred Stock, all of which shares are
issued and outstanding; (x) 4,842,397 shares of Preferred Stock have been
designated Series B Convertible Preferred Stock, 4,418,262 of which shares are
issued and outstanding; (y) 3,126,241 shares of Preferred Stock have been
designated as Series C Preferred Stock, all of which shares are issued and
outstanding, and (z) 8,509,675 shares of Series D Preferred Stock, of which
6,432,608 are issued and outstanding.

               (ii) On the date hereof, 43,639,400 shares of Common Stock are
reserved for issuance upon the exercise of options, warrants and convertible
preferred stock.

          4. Method of Payments.

                                  Page 3 of 11



          (a) Payment. Except in the event of an earlier conversion pursuant to
Section 3 hereof or an acceleration pursuant to Section 7 hereof,
notwithstanding anything contained elsewhere in this Convertible Note to the
contrary, the Company will pay all sums for principal, interest, premiums,
dividends or otherwise becoming due on this Convertible Note not later than 5:00
p.m. New York time, on the Maturity Date, in immediately available funds, in
accordance with the payment instructions that the Payee may designate in
writing, without the presentation or surrender of such Convertible Note or the
making of any notation thereon. Any payment made after 5:00 p.m. New York time,
on a Business Day will be deemed made on the next following Business Day. If the
Maturity Date falls on a day that is not a Business Day, such due date shall be
extended to the next succeeding Business Day, and interest shall be payable on
any principal so extended for the period of such extension. All amounts payable
under this Convertible Note shall be paid free and clear of, and without
reduction by reason of, any deduction, set-off or counterclaim. The Company will
afford the benefits of this Section to the Payee and to each other Person
holding this Convertible Note.

          (b) Transfer and Exchange. Upon surrender of any Convertible Note for
registration of transfer or for exchange to the Company at its principal office,
the Company at its sole expense will execute and deliver in exchange therefor a
new Convertible Note or Convertible Notes, as the case may be, as requested by
the holder or transferee, which aggregate the unpaid principal amount of such
Convertible Note, registered as such holder or transferee may request, dated so
that there will be no loss of interest on the Convertible Note and otherwise of
like tenor. The issuance of new Convertible Notes shall be made without charge
to the holder(s) of the surrendered Convertible Note for any issuance tax in
respect thereof or other cost incurred by the Company in connection with such
issuance, provided that each Convertible Noteholder shall pay any transfer taxes
associated therewith. The Company shall be entitled to regard the registered
holder of this Convertible Note as the holder of the Convertible Note so
registered for all purposes until the Company or its agent, as applicable, is
required to record a transfer of this Convertible Note on its register.

          (c) Replacement. Upon receipt of evidence reasonably satisfactory to
the Company of the loss, theft, destruction or mutilation of any Convertible
Note and, in the case of any such loss, theft or destruction of any Convertible
Note, upon receipt of an indemnity reasonably satisfactory to the Company or, in
the case of any such mutilation, upon the surrender and cancellation of such
Convertible Note, the Company, at its expense, will execute and deliver, in lieu
thereof, a new Convertible Note of like tenor and dated the date of such lost,
stolen, destroyed or mutilated Convertible Note.

          5. Representations and Warranties of Payee. Payee represents and
warrants to Company that:

          (a) Investment Purpose. Payee is acquiring this Convertible Note and
any and all securities into which this Convertible Note is convertible solely
for its own account for the purpose of investment and not with a view to or for
sale in connection with any distribution thereof, and has no present intention
or plan to effect any distribution thereof. The securities issuable upon
conversion hereof will bear a legend to the following effect:

                                  Page 4 of 11



                    "The securities represented by this certificate have not
                    been registered under the Securities Act of 1933, as amended
                    (the "Act"), or the laws of any state and may not be sold or
                    transferred except in compliance with the Act and such
                    laws."

          (b) Information. Payee has had the opportunity to conduct and complete
customary business, financial, and operational due diligence investigations and
Payee is satisfied with the results of the due diligence investigations
conducted by Payee. Payee has been furnished with all materials relating to the
business, finances and operations of the Company that has been requested by
Payee. In addition, Payee has reviewed the public filings made by the Company
with the SEC. Payee understands and acknowledges that its investment in this
Convertible Note involves a high degree of risk.

          (c) Sophistication. Payee is able to bear the economic risk of an
investment in the Convertible Note and can afford to sustain a total loss of
such investment, and has such knowledge and experience in financial and business
matters that it is capable of evaluating the merits and risks of the proposed
investment and therefore has the capacity to protect its own interests in
connection with the purchase of such Convertible Note.

          (d) Illiquidity. Payee understands that there is no public market for
the Convertible Note to be acquired by it and that there may never be a public
market for such Convertible Note or the preferred stock or other security to be
issued at conversion, and that such Purchaser may have to bear the risk of its
investment in such securities for a substantial period of time.

          (e) Accredited Investor. Payee is an "accredited investor" within the
meaning of Regulation D promulgated under the Securities Act. In addition, Payee
has received such information as it considers necessary or appropriate for
deciding whether to acquire the Convertible Note.

          (f) Requisite Power and Authority. Payee has all necessary power and
authority to execute this Convertible Note. This Convertible Note has been duly
executed and delivered by Payee, and when executed by Payee will constitute the
legal, valid and binding obligation of Payee, enforceable in accordance with its
terms, subject to applicable bankruptcy, insolvency, or other similar laws
affecting the enforceability of creditors' rights generally and court decisions
with respect thereto, and the discretion of courts in granting equitable
remedies.

          (g) No Conflict. The execution by Payee of this Convertible Note and
the consummation of the transactions contemplated hereby by Payee will not
result in any violation of or default under, any provision of the organizational
documents of Payee, any contract to which Payee is a party or any applicable
law, rule or regulation, which violation or default could

                                  Page 5 of 11



reasonably be expected to (i) affect the validity of this Convertible Note, (ii)
affect in any material respect any action taken or to be taken by Payee pursuant
to this Convertible Note, or (iii) have a material adverse effect on the
properties, assets, business or operations of such Payee.

          (h) Confidentiality. The terms and conditions of the Mutual
Non-Disclosure Agreement ("NDA"), if any, previously entered into by Payee and
the Company, shall govern the exchange of all confidential information between
the parties. The NDA shall survive execution of this Convertible Note.

          6. Representations and Warranties of the Company. The Company
represents and warrants to Payee that:

          (a) Organization and Qualification. The Company and each of its
subsidiaries is an entity duly organized, validly existing and in good standing
under the laws of its jurisdiction of organization, with power and authority to
conduct its business as it is now being conducted, to own or use its properties
and assets that it purports to own or use and, in the case of the Company, to
perform its obligations under this Convertible Note. The Company and each of its
subsidiaries is duly qualified to do business as a foreign company and is in
good standing under the laws of each state or other jurisdiction in which either
the ownership or use of the properties owned or used by it, or the nature of the
activities conducted by it, requires such qualification.

          (b) Absence of Conflicts. Neither the execution, delivery and
performance of this Convertible Note by the Company, nor the consummation of the
transactions contemplated hereby, nor compliance by the Company with any of the
provisions hereof, will (a) violate, conflict with, or result in a breach of any
provision of, constitute a default under, or permit or result in the termination
of, acceleration of any obligation under, or creation of a lien under any of the
terms, conditions or provisions of, (i) the certificate of incorporation, bylaws
or stockholders agreements of the Company, or (ii) any note, mortgage,
indenture, contract, agreement or license by which the Company or any of the
properties or assets thereof may be bound, or to which the Company or any
subsidiary thereof or any of the properties or assets thereof may be subject, or
(b) violate or conflict with any law, rule, regulation, judgment, ruling, order,
writ, injunction or decree applicable to the Company or any subsidiary thereof
or any of the properties or assets thereof.

          (c) Authorization of Agreements, Etc. Each of (i) the execution and
delivery by the Company of this Convertible Note, (ii) the performance by the
Company of its obligations hereunder, and (iii) the issuance, sale and delivery
by the Company of this Convertible Note and the shares of Series D Preferred
Stock or other security issuable upon conversion thereof has been duly
authorized by all necessary corporate action of the Company.

          (d) Validity. This Convertible Note has been duly executed and
delivered by the Company and constitutes the legal, valid and binding obligation
of the Company, enforceable against the Company in accordance with its terms.

                                  Page 6 of 11



          7. Events of Default. If any of the following events takes place
before the Maturity Date (each, an "Event of Default"), Payee at its option may
declare all principal and accrued and unpaid interest thereon and all other
amounts payable under this Convertible Note immediately due and payable in
immediately available cash funds; provided, however, that this Convertible Note
shall automatically become due and payable without any declaration in the case
of an Event of Default specified in clause 2, 3, 4, 5, 6 or 7, below:

          (1)  The Company fails to make payment of the full amount due under
               this Convertible Note (including, without limitation, principal,
               interest, premiums and other amounts) on demand at the Maturity
               Date or by the issuance of Series D Preferred Stock or Qualified
               Financing Securities, as the case may be following a valid Payee
               D Election or Payee F Election by Payee; or
          (2)  A receiver, liquidator or trustee is appointed by a court order
               (i) of the Company or (ii) for any substantial part of the
               Company's assets or properties; or
          (3)  The Company is adjudicated bankrupt or insolvent; or
          (4)  A substantial part of the Company's property is sequestered by or
               in consequence of a court order and such order remains in effect
               for more than 30 days; or
          (5)  The Company files a petition in voluntary bankruptcy or requests
               reorganization under any provision of any bankruptcy,
               reorganization or insolvency law or consents to the filing of any
               petition against it under such law, or
          (6)  Any petition against the Company is filed under bankruptcy,
               receivership or insolvency law; or
          (7)  The Company makes a formal or informal general assignment for the
               benefit of its creditors, or admits in writing its inability to
               pay debts generally when they become due, or consents to the
               appointment of a receiver, liquidator or trustee of the Company
               or for all or any part of its property; or
          (8)  An attachment or execution is levied against any substantial part
               of the Company's assets that is not released within 30 days; or
          (9)  The Company dissolves, liquidates or ceases business activity, or
               transfers the majority of its assets other than in the ordinary
               course of business; or
          (10) The Company breaches any material covenant or agreement on its
               part contained in this Convertible Note;
          (11) There exists any material inaccuracy or untruthfulness of any
               representation or warranty of the Company set forth in this
               Convertible Note; or
          (12) Except as with respect to defaults existing on the date hereof
               under those promissory notes, credit agreements, loan agreements,
               conditional sales contracts, guarantees, leases, indentures,
               bonds, debentures or other contract or material obligations set
               forth on Attachment A, the Company shall default under any
               promissory note, credit agreement, loan agreement, conditional
               sales contract, guarantee, lease, indenture, bond, debenture or
               other contract or material obligation to which it is a party
               whatsoever

                                  Page 7 of 11



               having an aggregate outstanding amount greater than $100,000 and
               a party thereto or a holder thereof is entitled to accelerate the
               obligations of the Company.

          8.   Definitions.

          "Business Day" means a day (other than a Saturday or Sunday) on which
banks generally are open in New York, New York for the conduct of substantially
all of their activities.

          "Convertible Note" shall mean this Convertible Promissory Note.

          "Convertible Notes" shall mean this Convertible Promissory Note along
with (i) any convertible notes substantially in the form of this Convertible
Note issued to UBS Capital LLC, (ii) any convertible note to be issued to
ROF/IFX, LLC if ROF/IFX, LLC has elected to receive a convertible note
substantially similar to the form of this Convertible Note pursuant to the terms
of the convertible note dated September 9, 2002 between ROF/IFX, LLC and the
Company and (iii) any other convertible notes in the form hereof issued upon
transfer or exchange hereof, in whole or in part.

          "Convertible Noteholder" with respect to any Convertible Note, means
at any time each Person then the record owner of such Convertible Note and
"Convertible Noteholders" means all of such Convertible Noteholders
collectively.

          "Person" means any person or entity of any nature whatsoever,
specifically including an individual, a firm, a company, a corporation, a
partnership, a limited liability company, a trust or other entity.

          "Series D Preferred Stock" means the series of convertible preferred
stock of the Company issued in the Series D Financing or, if necessary under
Delaware law, a new class of preferred stock having the same rights,
preferences, and privileges as the Series D Preferred Stock.

          "Series D Financing" means the issuance of convertible preferred stock
of the Company to one or more investors for cash pursuant to the Series D Stock
Purchase Agreement.

          "Series D Stock Purchase Agreement" means the IFX Corporation Series D
Convertible Preferred Stock Purchase Agreement dated as of February 19, 2002,
among the Company and the other parties named therein.

          "Qualified Financing" means the future issuance of Qualified Financing
Securities to one or more investors following the date of issuance of this
Convertible Note pursuant to a Qualified Financing Purchase Agreement, if any.

          "Qualified Financing Securities" means a new series of convertible
preferred stock, any common stock or any convertible debt of the Company to be
issued pursuant to a Qualified Financing Purchase Agreement, if any.

                                  Page 8 of 11



          "Qualified Financing Purchase Agreement" means an agreement executed
by the Company after the date hereof which provides the Company with debt or
equity financing in connection with the issuance of securities by the Company
consisting of IFX common stock or other securities that are convertible,
exercisable, or exchangeable into shares of IFX common stock.

          9. Expenses of Enforcement, etc. The Company agrees to pay all
reasonable fees and expenses incurred by the Payee in connection with the
negotiation, execution and delivery of this Convertible Note. The Company agrees
to pay all reasonable fees and expenses incurred by the Payee in connection with
any amendments, modifications, waivers, extensions, renewals, renegotiations or
"workouts" of the provisions hereof or incurred by the Payee in connection with
the enforcement or protection of the Payee's rights in connection with this
Convertible Note, or in connection with any pending or threatened action,
proceeding, or investigation relating to the foregoing, including but not
limited to the reasonable fees and expenses of counsel for the Payee. The
Company indemnifies the Payee and its directors, managers, affiliates, partners,
members, officers, employees and agents against, and agrees to hold the Payee
and each such person and/or entity harmless from, any and all losses, claims,
damages, liabilities and related expenses, including reasonable counsel fees and
expenses, incurred by or asserted against the Payee or any such person or entity
arising out of, in any way connected with, or as a result of (i) the
consummation of the loan evidenced by this Convertible Note and the use of the
proceeds thereof or (ii) any claim, litigation, investigation or proceedings
relating to any of the foregoing, whether or not the Payee or any such person or
entity is a party thereto.

          10. Amendment and Waiver. The provisions of this Convertible Note may
not be modified, amended or waived, and the Company may not take any action
herein prohibited, or omit to perform any act herein required to be performed by
it without the written consent of the Payee.

          11. Remedies Cumulative. No remedy herein conferred upon the Payee is
intended to be exclusive of any other remedy and each and every such remedy
shall be cumulative and shall be in addition to every other remedy given
hereunder or now or hereafter existing at law or in equity or by statute or
otherwise.

          12. Remedies Not Waived. No course of dealing between the Company and
the Payee or any delay on the part of the Payee in exercising any rights
hereunder shall operate as a waiver of any right of the Payee.

          13. Assignments. The Payee may assign, participate, transfer or
otherwise convey this Convertible Note and any of its rights or obligations
hereunder or interest herein to any Person, and this Convertible Note shall
inure to the benefit of the Payee's successors and assigns. The Company shall
not assign or delegate this Convertible Note or any of its liabilities or
obligations hereunder.

          14. Headings. The headings of the sections and paragraphs of this
Convertible Note are inserted for convenience only and do not constitute a part
of this Convertible Note.

                                  Page 9 of 11



          15. Severability. If any provision of this Convertible Note is held
invalid or unenforceable by any court of competent jurisdiction, the other
provisions of this Convertible Note will remain in full force and effect. Any
provision of this Convertible Note held invalid or unenforceable only in part or
degree will remain in full force and effect to the extent not held invalid or
unenforceable.

          16. Cancellation. After all principal, premiums (if any), accrued
interest and all other amounts at any time owed under or in connection with this
Convertible Note have been paid in full in immediately available funds, or this
Convertible Note has been converted in accordance with its terms, this
Convertible Note will be surrendered to the Company for cancellation and will
not be reissued.

          17. Maximum Legal Rate. If at any time an interest rate applicable
hereunder exceeds the maximum rate permitted by law, such rate shall be reduced
to the maximum rate so permitted by law.

          18. Place of Payment and Notices. Subject to Section 4(a) above,
payments of principal and interest and notices deliverable to the Payee
hereunder are to be delivered to the Payee at the address as the Payee has
specified by prior written notice to the Company. No notice shall be deemed to
have been delivered until the first Business Day following actual receipt
thereof at the foregoing address.

          19. Waiver of Jury Trial. The Payee and the Company each hereby waives
any right it may have to a trial by jury in respect of any litigation directly
or indirectly arising out of, under or in connection with this Convertible Note
or the transactions contemplated hereunder.

          20. Submission to Jurisdiction. (a) Any legal action or proceeding
with respect to this Convertible Note may be brought in the courts of the State
of New York or of the United States of America for the Southern District of New
York, and, by execution and delivery of this Convertible Note, the Company
hereby accepts for itself and in respect of its property, generally and
unconditionally, the jurisdiction of the aforesaid courts.

          (b) The Company hereby irrevocably waives, in connection with any such
action or proceeding, any objection, including, without limitation, any
objection to the laying of venue or based on the grounds of forum non
conveniens, which they may now or hereafter have to the bringing of any such
action or proceeding in such respective jurisdictions.

          (c) Nothing herein shall affect the right of the Payee to serve
process in any other manner permitted by law or to commence legal proceedings or
otherwise proceed against the Company in any other jurisdiction.

          21. GOVERNING LAW. ALL ISSUES AND QUESTIONS CONCERNING THE
CONSTRUCTION, VALIDITY, ENFORCEMENT AND INTERPRETATION OF THIS CONVERTIBLE NOTE
SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF
NEW YORK.

                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]

                                 Page 10 of 11



          IN WITNESS WHEREOF, the Company has executed and delivered this
Convertible Promissory Note on the date first written above.

                                                     IFX CORPORATION


                                                     By:  /s/ Joel Eidelstein
                                                          ----------------------
                                                          Name: Joel Eidelstein
                                                          Title: President

Agreed to and accepted:

PAYEE:

UBS CAPITAL AMERICAS III, L.P.


By:  UBS Capital Americas III, LLC


By: /s/ George A. Duarte
    --------------------------
Name: George A. Duarte
Title: Partner


By: /s/ Marc Unger
    --------------------------
Name: Marc Unger
Title: Chief Financial Officer

Address:       UBS Capital Americas III, L.P.
               c/o UBS Capital Americas III, LLC
               299 Park Avenue
               New York, NY  10171
               Attention:  George Duarte
Telephone No.: (212) 821-6330
Telecopy No.:  (212) 821-6333

                                 Page 11 of 11