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                                    EXHIBIT B

                                     BY-LAWS

                                       OF

                               USTN HOLDINGS, INC.

                 (formerly known as U.S. TELNET HOLDINGS, INC.)

                                    ARTICLE I

                                     OFFICES

        SECTION 1. REGISTERED OFFICE. The registered office of USTN HOLDINGS,
INC. (the "Corporation") shall be established and maintained at the office of
the Prentice-Hall Corporation Systems, Inc., in the City of Dover, in the County
of Kent, in the State of Delaware, and said corporation shall be the registered
agent of this Corporation.

        SECTION 2. OTHER OFFICES. The Corporation may have other offices, either
within or without the State of Delaware, at such place or places as the Board of
Directors may from time to time appoint or the business of the Corporation may
require.

                                   ARTICLE II

                            MEETINGS OF STOCKHOLDERS

        SECTION 1. ANNUAL MEETINGS. Annual meetings of stockholders for the
election of directors and for such other business as may be stated in the notice
of the meeting, shall be held at such place, either within or without the State
of Delaware, and at such time and date as the Board of Directors, by resolution,
shall determine and as set forth in the notice of the meeting. In the event the
Board of Directors fails to so determine the time, date and place of meeting,
the annual meeting of stockholders shall be held at the principal office of the
Corporation at 203 North LaSalle Street, Chicago, Illinois 60601-1293 on the
first Monday in June.

        If the date of the annual meeting shall fall upon a legal holiday, the
meeting shall be held on the next succeeding business day. At each annual
meeting, the stockholders entitled to vote shall elect a Board of Directors and
they may transact such other corporate business as shall be stated in the notice
of the meeting.

        SECTION 2. OTHER MEETINGS. Meetings of stockholders for any purpose
other than the election of directors may be held at such time and place, within
or without the State of Delaware, as shall be stated in the notice of the
meeting.

        SECTION 3. VOTING. Each stockholder entitled to vote in accordance with
the terms of the Certificate of Incorporation and in accordance with the
provisions of these By-Laws shall be entitled to one vote, in person or by
proxy, for each share of stock entitled to vote held by


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such stockholder, but no proxy shall be voted after eleven (11) months from its
date unless such proxy provides for a longer period. Upon the demand of any
stockholder, the vote for directors and the vote upon any question before the
meeting shall be by ballot. All elections for directors shall be decided by
plurality vote; all other questions shall be determined by majority vote except
as otherwise provided by the Certificate of Incorporation or the laws of the
State of Delaware.

        A complete list of the stockholders entitled to vote at the meeting,
arranged in alphabetical order, with the address of each, and the number of
shares held by each, shall be open to the examination of any stockholder, for
any purpose germane to the meeting, during ordinary business hours, for a period
of at least ten days prior to the meeting, either at a place within the city
where the meeting is to be held, which place shall be specified in the notice of
the meeting, or, if not so specified, at the place where the meeting is to be
held. The list shall also be produced and kept at the time and place of the
meeting during the whole time thereof, and may be inspected by any stockholder
who is present.

        SECTION 4. QUORUM. Except as otherwise required by these By-Laws, the
presence, in person or by proxy, of stockholders holding a majority of the stock
of the Corporation entitled to vote shall constitute a quorum at all meetings of
the stockholders. In case a quorum shall not be present at any meeting, a
majority in interest of the stockholders entitled to vote thereat, present in
person or by proxy, shall have power to adjourn the meeting from time to time,
without notice other than announcement at the meeting, until the requisite
amount of stock entitled to vote shall be present. At any such adjourned meeting
at which the requisite amount of stock entitled to vote shall be represented,
any business may be transacted which might have been transacted at the meeting
as originally noticed; but only those stockholders entitled to vote at the
meeting as originally noticed shall be entitled to vote at any adjournment or
adjournments thereof.

        SECTION 5. SPECIAL MEETINGS. Special meetings of the stockholders may be
held whenever and wherever called for by the Chairman of the Board of Directors,
the President or the Board of Directors, or by the written demand of the holders
of no fewer than one-third of all the shares of capital stock entitled to vote
at the meeting. The business which may be conducted at any such special meeting
shall be confined to the purposes stated in the notice thereof, including the
election and/or removal of directors.

        SECTION 6. NOTICE OF MEETINGS. Written notice, stating the place, date
and time of the meeting, and the purpose or purposes for which the meeting is
called, shall be given to each stockholder entitled to vote thereat at his
address as it appears on the records of the Corporation, not less than ten nor
more than sixty days before the date of the meeting. No business other than that
stated in the notice shall be transacted at any meeting without the consent of
the majority of stockholders entitled to vote thereat.

        SECTION 7. INSPECTORS OF ELECTION.

                (a)     At such time as the Corporation becomes subject to
Section 231 of the General Corporation Law of the State of Delaware, the
provisions of this Section 7 shall become applicable. The Corporation shall, in
advance of any meeting of stockholders, appoint one or more inspectors to act at
the meeting and make a written report thereof. The Corporation may



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designate one or more persons as alternate inspectors to replace any inspector
who fails to act. If no inspector or alternate is able to act at a meeting of
stockholders, the person presiding at the meeting shall appoint one or more
inspectors to act at the meeting. Each inspector, before entering upon the
discharge of his duties, shall take and sign an oath faithfully to execute the
duties of inspector with strict impartiality and according to the best of his
ability.

                (b)     The inspectors shall (i) ascertain the number of shares
outstanding and the voting power of each, (ii) determine the shares represented
at a meeting and the validity of proxies and ballots, (iii) count all votes and
ballots, (iv) determine and retain for a reasonable period a record of the
disposition of any challenges made to any determination by the inspectors, and
(v) certify their determination of the number of shares represented at the
meeting, and their count of all votes and ballots. The inspectors may appoint or
retain other persons or entities to assist the inspectors in the performance of
the duties of the inspectors.

                (c)     The date and time of the opening and the closing of the
polls for each matter upon which the stockholders will vote at a meeting shall
be announced at the meeting. No ballot, proxies or votes, nor any revocations
thereof or changes thereto, shall be accepted by the inspectors after the
closing of the polls unless the Court of Chancery upon application by a
stockholder shall determine otherwise.

                (d)     In determining the validity and counting of proxies and
ballots, the inspectors shall be limited to an examination of the proxies, any
envelopes submitted with those proxies, any information provided in accordance
with Section 212(c)(2) of the General Corporation Law of the State of Delaware,
ballots and the regular books and records of the Corporation, except that the
inspectors may consider other reliable information for the limited purpose of
reconciling proxies and ballots submitted by or on behalf of banks, brokers,
their nominees or similar persons which represent more votes than the holder of
a proxy is authorized by the record owner to cast or more votes than the
stockholder holds of record. If the inspectors consider other reliable
information for the limited purpose permitted herein, the inspectors at the time
they make their certification pursuant to subsection (b)(v) of this Section 7
shall specify the precise information considered by them including the person or
persons from whom they obtained the information, when the information was
obtained, the means by which the information was obtained and the basis for the
inspectors' belief that such information is accurate and reliable.

        SECTION 8. CONDUCT OF STOCKHOLDERS' MEETINGS. The meetings of the
stockholders shall be presided over by the Chairman of the Board, or if he is
not present, by the President, or if neither of such officers is present, by a
Vice President designated by the Board of Directors, or if none of such officers
is present, by a chairman to be elected at the meeting. The Secretary of the
Corporation, if present, shall act as secretary of such meetings or, if he is
not present, an Assistant Secretary designated by the chairman of the meeting
shall so act; if neither the Secretary nor an Assistant Secretary is present,
then a secretary shall be appointed by the chairman of the meeting. The order of
business shall be as determined by the chairman of the meeting.



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                                  ARTICLE III

                                    DIRECTORS

        SECTION 1. GENERAL POWERS. The property and business of the Corporation
shall be managed by its Board of Directors, which shall possess all the powers
of the Corporation except as may be otherwise provided by statute or by the
certificate of incorporation or by these by-laws.

        The board of directors may hold its meetings, establish corporate
offices and agencies, and keep the books of the Corporation at such places
either within or without the State of Delaware as it may from time to time
determine.

        SECTION 2. NUMBER OF DIRECTORS. The number of directors of the
Corporation which shall constitute the entire Board shall initially be sixteen
(16), but such number may be changed from time to time to a number not less than
five (5) nor more than sixteen (16) by resolution adopted by a majority of the
entire Board; provided, however, that the number of directors constituting the
entire Board shall not be decreased by the Board of Directors below the number
then in office unless such decrease shall become effective at any annual meeting
of stockholders. The directors shall be elected at the annual meeting of the
stockholders and each director shall be elected to serve until his successor
shall be elected and shall qualify. As used in these By-laws, "entire Board"
means the total number of directors the Corporation would have if there were no
vacancies.

        SECTION 3. RESIGNATIONS. Any director, member of a committee or other
officer may resign at any time. Such resignation shall be made in writing, and
shall take effect at the time specified therein, and if no time be specified, at
the time of its receipt by the Chairman of the Board of Directors, President or
Secretary. The acceptance of a resignation shall not be necessary to make it
effective.

        SECTION 4. VACANCIES. If the office of any director, member of a
committee or other officer becomes vacant, the remaining directors in office,
though less than a quorum by a majority vote, may appoint any qualified person
to fill such vacancy, who shall hold office for the unexpired term and until his
successor shall be duly chosen.

        SECTION 5. REMOVAL. Except as hereinafter provided, any director or
directors may be removed either for or without cause at any time by the
affirmative vote of the holders of a majority of all the shares of stock
outstanding and entitled to vote, at a special meeting of the stockholders
called for the purpose and the vacancies thus created may be filled, at the
meeting held for the purpose of removal, by the affirmative vote of a majority
in interest of the stockholders entitled to vote.

        SECTION 6. INCREASE OR DECREASE OF NUMBER. The number of directors may
be increased or decreased by amendment of these By-Laws by the affirmative vote
of a majority of the directors, though less than a quorum, or, by the
affirmative vote of a majority in interest of the stockholders, at the annual
meeting or at a special meeting called for that purpose.



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        SECTION 7. POWERS. The Board of Directors shall exercise all of the
powers of the Corporation except such as are by law, or by the Certificate of
Incorporation of the Corporation or by these By-Laws conferred upon or reserved
to the stockholders.

        SECTION 8. COMMITTEES. The Board of Directors may, by resolution or
resolutions passed by a majority of the whole board, designate one or more
committees, each committee to consist of one or more of the directors of the
Corporation. The Board may designate one or more directors as alternate members
of any committee, who may replace any absent or disqualified member at any
meeting of the committee. In the absence or disqualification of any member of
such committee or committees, the member or members thereof present at any
meeting and not disqualified from voting, whether or not he or they constitute a
quorum, may unanimously appoint another member of the Board of Directors to act
at the meeting in the place of any such absent or disqualified member.

        Any such committee, to the extent provided in the resolution of the
Board of Directors, or in these By-Laws, shall have and may exercise all the
powers and authority of the Board of Directors in the management of the business
and affairs of the Corporation, and may authorize the seal of the Corporation to
be affixed to all papers which may require it; but no such committee shall have
the power or authority in reference to amending the Certificate of
Incorporation, adopting an agreement of merger or consolidation, recommending to
the stockholders the sale, lease or exchange of all or substantially all of the
Corporation's property and assets, recommending to the stockholders a
dissolution of the Corporation or a revocation of a dissolution, or amending the
By-Laws of the Corporation; and, unless the resolution, these By-Laws, or the
Certificate of Incorporation expressly so provide, no such committee shall have
the power or authority to declare a dividend or to authorize the issuance of
stock.

        SECTION 9. MEETINGS. The newly elected directors may hold their first
meeting for the purpose of organization and the transaction of business, if a
quorum be present, immediately after the annual meeting of the stockholders; or
the time and place of such meeting may be fixed by consent in writing of all the
directors.

        Regular meetings of the directors may be held without notice at such
places and times as shall be determined from time to time by resolution of the
directors.

        Special meetings of the board may be called by the Chairman, the
President or by the Secretary on the written request of any four directors on at
least four days' prior notice to each director and shall be held at such place
or places as may be determined by the directors, or as shall be stated in the
call of the meeting.

        Unless otherwise restricted by the Certificate of Incorporation or these
By-Laws, members of the Board of Directors, or any committee designated by the
Board of Directors, may participate in a meeting of the Board of Directors, or
any committee, by means of conference telephone or similar communications
equipment by means of which all persons participating in the meeting can hear
each other, and such participation in a meeting shall constitute presence in
person at the meeting.



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        SECTION 10. QUORUM. A majority of the entire Board shall constitute a
quorum for the transaction of business. If at any meeting of the board there
shall be less than a quorum present, a majority of those present may adjourn the
meeting from time to time until a quorum is obtained, and no further notice
thereof need be given other than by announcement at the meeting which shall be
so adjourned. The vote of the majority of directors present at a meeting at
which a quorum is present shall be the act of the Board of Directors unless the
Certificate of Incorporation or these By-laws shall require a vote of a greater
number.

        SECTION 11. COMPENSATION. Directors shall receive such compensation for
their services as directors or as members of committees, as may be fixed by
resolution of the Board of Directors, including but not limited to a stated
salary, fixed fee, or hourly rate and expenses of attendance for attendance at
each meeting or engagement or activity on behalf of this Corporation. Nothing
herein contained shall be construed to preclude any director from serving the
Corporation in any other capacity as an officer, agent or otherwise, and
receiving compensation therefor.

        SECTION 12. ACTION WITHOUT MEETING. Any action required or permitted to
be taken at any meeting of the Board of Directors, or of any committee thereof,
may be taken without a meeting, if all members of the Board or of such committee
as the case may be, consent thereto in writing and the writing or writings and
such written consent is filed with the minutes of proceedings of the Board or
committee.

                                   ARTICLE IV

                                    OFFICERS

        SECTION 1. OFFICERS. The officers of the Corporation shall be a Chairman
of the Board of Directors, a President, a Treasurer, and a Secretary, all of
whom shall be elected by the Board of Directors and who shall hold office until
their successors are elected and qualified. In addition, the Board of Directors
may elect one or more Vice-Presidents and such Assistant Secretaries and
Assistant Treasurers as they may deem proper. None of the officers (other than
the Chairman of the Board of Directors) need be directors. The officers shall be
elected at the first meeting of the Board of Directors after each annual
meeting, and vacancies in any office and newly created offices may be filled by
the Board at any time. Any two or more offices may be held by the same person.

        SECTION 2. REMOVAL OF OFFICERS. Any officer may be removed, either with
or without cause, by the vote of a majority of the directors then in office at
any meeting of the board of directors, but such removal shall be without
prejudice to the contract rights, if any, of the person so removed.

        SECTION 3. OTHER OFFICERS AND AGENTS. The Board of Directors may appoint
such other officers and agents as it may deem advisable, who shall hold their
offices for such terms and shall exercise such powers and perform such duties as
shall be determined from time to time by the Board of Directors.



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        SECTION 4. CHAIRMAN OF THE BOARD OF DIRECTORS. The Chairman of the Board
of Directors shall preside at all meetings of directors and stockholders of the
Corporation and may call meetings of the Board of Directors. The Chairman of the
Board of Directors shall also perform such other duties as may be assigned to
him by the Board of Directors.

        SECTION 5. PRESIDENT. The President shall be the chief executive officer
of the Corporation and shall formulate policies with respect to the affairs of
the Corporation and have general powers of supervision and management. In the
absence of the Chairman of the Board of Directors, the President shall preside
at meetings of the stockholders and the Board of Directors. Except as the Board
of Directors shall authorize the execution thereof in some other manner, the
President shall be authorized to execute bonds, mortgages and other contracts on
behalf of the Corporation to cause the Corporation's seal to be affixed to any
instrument requiring such seal, and when so affixed such seal shall be attested
by the signatures of the Secretary or Assistant Secretary.

        SECTION 6. VICE-PRESIDENT. Each Vice-President shall have such powers
and shall perform such duties as shall be assigned to him by the directors.

        SECTION 7. TREASURER. The Treasurer shall have the custody of the
corporate funds and securities and shall keep full and accurate account of
receipts and disbursements in books belonging to the Corporation. He shall
deposit all moneys and other valuables in the name and to the credit of the
Corporation in such depositaries as may be designated by the Board of Directors.

        The Treasurer shall disburse the funds of the Corporation as may be
ordered by the Board of Directors, the Chairman of the Board of Directors or the
President, taking proper vouchers for such disbursements. He shall render to the
Chairman of the Board of Directors, the President and Board of Directors at the
regular meetings of the Board of Directors, or whenever they may request it, an
account of all his transactions as Treasurer and of the financial condition of
the Corporation. If required by the Board of Directors, he shall give the
Corporation a bond for the faithful discharge of his duties in such amount and
with such surety as the board shall prescribe.

        SECTION 8. SECRETARY. The Secretary shall give, or cause to be given,
notice of all meetings of stockholders and directors, and all other notices
required by law or by these By-Laws, and in case of his absence or refusal or
neglect so to do, any such notice may be given by any person thereunto directed
by the Chairman of the Board of Directors, the President, or by the directors,
or stockholders, upon whose requisition the meeting is called as provided in
these By-Laws. He shall record all the proceedings of the meetings of the
Corporation and of the directors in a book to be kept for that purpose, and
shall perform such other duties as may be assigned to him by the directors the
Chairman of the Board of Directors or the President. He shall have the custody
of the seal of the Corporation and shall affix the same to all instruments
requiring it, when authorized by the directors or the Chairman of the Board of
Directors or the President, and attest the same.



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        SECTION 9. ASSISTANT TREASURERS AND ASSISTANT SECRETARIES. Assistant
Treasurers and Assistant Secretaries, if any, shall be elected and shall have
such powers and shall perform such duties as shall be assigned to them,
respectively, by the directors.

                                    ARTICLE V

                                  MISCELLANEOUS

        SECTION 1. CERTIFICATES OF STOCK. A certificate of stock, signed by the
Chairman of the Board of Directors, the President or Vice-President, and the
Treasurer or an Assistant Treasurer, or Secretary or an Assistant Secretary,
shall be issued to each stockholder certifying the number of shares owned by him
in the Corporation. Any of or all the signatures may be facsimiles.

        SECTION 2. LOST CERTIFICATES. A new certificate of stock may be issued
in the place of any certificate theretofore issued by the Corporation, alleged
to have been lost or destroyed, and the directors may, in their discretion,
require the owner of the lost or destroyed certificate, or his legal
representatives, to give the Corporation a bond, in such sum as they may direct,
not exceeding double the value of the stock, to indemnify the Corporation
against any claim that may be made against it on account of the alleged loss of
any such certificate, or the issuance of any such new certificate.

        SECTION 3. TRANSFER OF SHARES. The shares of stock of the Corporation
shall be transferable only upon its books by the holders thereof in person or by
their duly authorized attorneys or legal representatives, and upon such transfer
the old certificates shall be surrendered to the Corporation by the delivery
thereof to the person in charge of the stock and transfer books and ledgers, or
to such other person as the directors may designate, by whom they shall be
cancelled, and new certificates shall thereupon be issued. A record shall be
made of each transfer and whenever a transfer shall be made for collateral
security, and not absolutely, it shall be so expressed in the entry of the
transfer.

        SECTION 4. RECORD DATE. In order that the Corporation may determine the
stockholders entitled to notice of or to vote at any meeting of stockholders or
any adjournment thereof, or to express consent to corporate action in writing
without a meeting, or entitled to receive payment of any dividend or other
distribution or allotment of any rights, or entitled to exercise any rights in
respect of any change, conversion or exchange of stock or for the purpose of any
other lawful action, the Board of Directors may fix, in advance, a record date,
which shall not be more than sixty nor less than ten days before the date of
such meeting, nor more than sixty days prior to any other action. A
determination of stockholders of record entitled to notice of or to vote at a
meeting of stockholders shall apply to any adjournment of the meeting; provided,
however, that the Board of Directors may fix a new record date for the adjourned
meeting.

        SECTION 5. DIVIDENDS. Subject to the provisions of the Certificate of
Incorporation, the Board of Directors may, out of funds legally available
therefor at any regular or special meeting, declare dividends upon the capital
stock of the Corporation as and when they deem expedient. Before declaring any
dividend there may be set apart out of any funds of the Corporation available
for dividends, such sum or sums as the directors from time to time in their



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discretion deem proper for working capital or as a reserve fund to meet
contingencies or for equalizing dividends or for such other purposes as the
directors shall deem conducive to the interests of the Corporation.

        SECTION 6. SEAL. The corporate seal shall be circular in form and shall
contain the name of the Corporation, the year of its creation and the words
"CORPORATE SEAL DELAWARE". Said seal may be used by causing it or a facsimile
thereof to be impressed or affixed or reproduced or otherwise.

        SECTION 7. FISCAL YEAR. The fiscal year of the Corporation shall be
determined by resolution of the Board of Directors.

        SECTION 8. CHECKS. All checks, drafts or other orders for the payment of
money, notes or other evidences of indebtedness issued in the name of the
Corporation shall be signed by such officer or officers, agent or agents of the
Corporation, and in such manner as shall be determined from time to time by
resolution of the Board of Directors.

        SECTION 9. NOTICE AND WAIVER OF NOTICE. Whenever any notice is required
by these By-Laws to be given, personal notice is not meant unless expressly so
stated, and any notice so required shall be deemed to be sufficient if given by
depositing the same in the United States mail, postage prepaid, addressed to the
person entitled thereto at his address as it appears on the records of the
Corporation, and such notice shall be deemed to have been given on the day of
such mailing. Stockholders not entitled to vote shall not be entitled to receive
notice of any meetings except as otherwise provided by law.

        Whenever any notice whatever is required to be given under the
provisions of any law, or under the provisions of the Certificate of
Incorporation of the Corporation or these By-Laws, a waiver thereof in writing,
signed by the person or persons entitled to said notice, whether before or after
the time stated therein, shall be deemed equivalent thereto.

                                   ARTICLE VI

                                   AMENDMENTS

        These By-Laws may be altered or repealed and By-Laws may be made at any
annual meeting of the stockholders or at any special meeting thereof if notice
of the proposed alteration or repeal or By-Law or By-Laws to be made be
contained in the notice of such special meeting, by the affirmative vote of a
majority of the stock issued and outstanding and entitled to vote thereat, or by
the affirmative vote of a majority of the Board of Directors, at any regular
meeting of the Board of Directors, or at any special meeting of the Board of
Directors, if notice of the proposed alteration or repeal, or By-Law or By-Laws
to be made, be contained in the notice of such special meeting.



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                                  ARTICLE VII

                          INDEMNIFICATION OF OFFICERS,
                         DIRECTORS, EMPLOYEES AND AGENTS

        SECTION 1. The Corporation may indemnify any person who was or is a
party or is threatened to be made a party to any threatened, pending or
completed action, suit or proceeding, whether civil, criminal, administrative or
investigative (other than an action by or in the right of the Corporation) by
reason of the fact that he is or was a director, officer, employee or agent of
the Corporation, or who is or was serving at the request of the Corporation as a
director, officer, employee or agent of another Corporation, partnership, joint
venture, trust or other enterprise, against expenses (including attorneys'
fees), judgments, fines and amounts, paid in settlement actually and reasonably
incurred by him in connection with such action, suit or proceeding if he acted
in good faith and in a manner he reasonably believed to be in or not opposed to
the best interests of the Corporation, and, with respect to any criminal action
or proceeding, had no reasonable cause to believe his conduct was unlawful. The
determination of any action, suit or proceeding by judgment, order, settlement,
conviction, or upon a plea of nolo contendere or its equivalent, shall not, of
itself, create a presumption that the person did not act in good faith and in a
manner which he reasonably believed to be in or not opposed to the best
interests of the Corporation, and with respect to any criminal action or
proceeding, had reasonable cause to believe that his conduct was unlawful.

        SECTION 2. The Corporation may indemnify any person who was or is a
party or is threatened to be made a party to any threatened, pending or
completed action or suit by or in the right of the Corporation to procure a
judgment in its favor by reason of the fact that he is or was a director,
officer, employee or agent of the Corporation, or is or was serving at the
request of the Corporation as a director, officer, employee or agent of another
Corporation, partnership, joint venture, trust or other enterprise, against
expenses (including attorneys' fees) actually and reasonably incurred by him in
connection with the defense or settlement of such action or suit if he acted in
good faith and in a manner he reasonably believed to be in or not opposed to the
best interests of the Corporation and except that no indemnification shall be
made in respect of any claim, issue or matter as to which such person shall have
been adjudged to be liable for negligence or misconduct in the performance of
his duty to the Corporation unless and only to the extent that the court in
which such action or suit was brought shall determine upon application, that
despite the adjudication of liability but in view of all the circumstances of
the case, such person is fairly and reasonably entitled to indemnity for such
expenses which the court shall deem proper.

        SECTION 3. To the extent that a director, officer, employee or agent of
the Corporation has been successful on the merits or otherwise in the defense of
any action, suit or proceeding referred to in Sections 1 and 2, or in defense of
any claim, issue or matter therein, he shall be indemnified against expenses
(including attorneys' fees) actually and reasonably incurred by him in
connection therewith.

        SECTION 4. Any indemnification under Sections I and 2 (unless ordered by
a court) shall be made by the Corporation only as authorized in the specific
case upon a determination that indemnification of the director, officer,
employee or agent is proper in the circumstances



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because he has met the applicable standard of conduct set forth in Sections 1
and 2. Such determination shall be made (a) by the board of directors by a
majority vote of a quorum consisting of directors who were not parties to such
action, suit or proceeding, or (b) if such a quorum is not obtainable, or, even
if obtainable, a quorum of disinterested directors so directs, by independent
legal counsel in a written opinion, or (c) by the stockholders.

        SECTION 5. Expenses (including attorneys' fees) incurred in defending a
civil, criminal, administrative or investigative action, suit or proceeding may
be paid by the Corporation in advance of the final disposition of such action,
suit or proceeding upon receipt of an undertaking by or on behalf of the
director or officer to repay such amount if it shall ultimately be determined
that he is not entitled to be indemnified by the Corporation as authorized in
this Article. Such expenses (including attorneys' fees) incurred by other
employees and agents may be so paid upon such terms and conditions, if any, as
the board of directors deems appropriate.

        SECTION 6. The indemnification and advancement of expenses provided by
this Article shall not be deemed exclusive of any other rights to which those
indemnified may be entitled under any contract, agreement, vote of stockholders
or disinterested directors or otherwise, both as to action in his official
capacity and as to action in another capacity while holding such office.

        SECTION 7. The Corporation shall have power to purchase and maintain
insurance on behalf of any person who is or was a director, officer, employee or
agent of the Corporation, or who is or was serving at the request of the
Corporation as a director, officer, employee or agent of another Corporation,
partnership, joint venture, trust or other enterprise against any liability
asserted against him and incurred by him in any such capacity, or arising out of
his status as such, whether or not the Corporation would have the power to
indemnify him against such liability under the provisions of this Article.

        SECTION 8. The indemnification and advancement of expenses provided by,
or granted pursuant to, this Article shall, unless otherwise provided when
authorized or ratified, continue as to a person who has ceased to be a director,
officer, employee or agent and shall inure to the benefit of the heirs,
executors and administrators of such a person.



                                       11

<PAGE>   12

                         FIRST AMENDMENT TO THE BY-LAWS
                                       OF
                            ILLUMINET HOLDINGS, INC.

        Pursuant to the Annual Meeting of Stockholders of Illuminet Holdings,
Inc., (f/k/a U.S. Telnet Holdings, Inc. and USTN Holdings, Inc.) a Delaware
corporation (the "Corporation"), dated June 13, 1996, the By-Laws of the
Corporation are hereby amended as follows:

        1.      Article III, Section 2 of the By-Laws is hereby amended and
restated in its entirety so as to read as follows:

                SECTION 2. NUMBER OF DIRECTORS. The number of directors of the
                Corporation which shall constitute the entire Board shall
                initially be sixteen (16) but such number may be changed from
                time to time to a number not less than five (5) nor more than
                sixteen (16) by resolution adopted by a majority of the entire
                Board; provided, however, that the number of directors
                constituting the entire Board shall not be decreased by the
                Board of Directors below the number then in office unless such
                decrease shall become effective at any annual meeting of
                stockholders. The Board shall be divided into three classes,
                which are hereby designated Class I, Class II and Class III. The
                term of office of the initial Class I directors shall expire at
                the 1997 Annual Meeting of Stockholders; that of the initial
                Class II directors at the 1998 Annual Meeting of Stockholders;
                and that of the initial Class III directors at the 1999 Annual
                Meeting of Stockholders. At each annual meeting after the
                initial classification of directors, directors to replace those
                whose terms expire at such annual meeting shall be elected to
                hold office until the third succeeding annual meeting. The
                directors shall be elected at the annual meeting of the
                stockholders and each director shall be elected to serve until
                his successor shall be elected and shall qualify. As used in
                these By-Laws, "entire Board" means the total number of
                directors the Corporation would have if there were no vacancies.

        2.      The following shall be added to the end of Article III, Section
                5 of the By-Laws.

                After January 1, 1997, directors may not be elected or
                re-elected to the Board after attaining the age of sixty-five
                years old. Directors who attain the age of sixty-five years old
                during their term will be allowed to complete their full term.

        3.      Article VI of the By-Laws is hereby amended and restated in its
entirety so as to read as follows:



<PAGE>   13

                                   ARTICLE VI

                                   AMENDMENTS

                These By-Laws may be altered or repealed and By-Laws may be made
                at any annual meeting of the stockholders or at any special
                meeting thereof if notice of the proposed alteration or repeal
                or By-Law or By-Laws to be made be contained in the notice of
                such special meeting, by the affirmative vote of a majority of
                the stock issued and outstanding and entitled to vote thereat,
                or by the affirmative vote of a majority of the Board of
                Directors, at any regular meeting of the Board of Directors, or
                at any special meeting of the Board of Directors if notice of
                the proposed alteration or repeal, or By-Law or By-Laws to be
                made, be contained in the notice of such special meeting;
                provided, however, that the affirmative vote of two-thirds (2/3)
                of a majority of the stock issued and outstanding and entitled
                to vote thereat shall be required to amend Article III, Section
                2 of these By-Laws.

IN WITNESS WHEREOF, the By-Laws are so amended as of this 13th day of June 1996.


                                        ----------------------------------------
                                        Secretary