DEMAND PROMISSORY NOTE

Date:  February 1, 2001                         Principal Amount: $94,000,000.00


           DTI Holdings,  Inc., a Missouri  corporation  (herein  referred to as
"Borrower"),  promises  to pay to the  order of KLT  Telecom  Inc.,  a  Missouri
corporation  (herein  referred to as "Lender"),  at its offices located at 10740
Nall,  Suite 230,  Overland  Park, KS 66211 or at such other place as Lender may
designate,  the  principal sum of Ninety Four Million  Dollars  ($94,000,000.00)
together with interest on the outstanding principal balance at a rate of 10% per
annum. The entire unpaid principal balance of this Note shall be immediately due
and payable UPON DEMAND by Lender, and Borrower  acknowledges that any condition
or requirement set forth in any other agreement  between  Borrower and Lender is
not the only basis upon which  demand  can be made  hereunder.  Interest  on the
unpaid  principal  of this Note will be due and payable  when demand is made for
payment of the principal of this Note.

           Borrower may prepay this Note,  in whole or in part,  at any time and
from time to time, without premium or penalty.  Any prepayments made by Borrower
shall be applied as follows:  first, to accrued and unpaid interest;  second, to
any other amounts payable  hereunder at the time a payment is made; and finally,
to the unpaid balance  remaining on the Note.  Interest shall be computed on the
basis of a 360-day year  consisting  of twelve (12) months with thirty (30) days
each.

           Except as otherwise  provided in this Note,  all notices  required or
permitted  hereunder  (including a notice by Lender demanding payment hereunder)
shall be in  writing.  A written  notice  shall be  deemed  to have  been  given
hereunder  (i) if delivered by hand,  when the  notifying  party  delivers  such
notice or other communication to the other party; (ii) if delivered by facsimile
or overnight delivery service, on the first business day following the date such
notice or other communication is transmitted by facsimile or timely delivered by
overnight  courier,  or (iii) if  delivered by mail,  on the third  business day
following the date such notice or other  communication  is deposited in the U.S.
mail by  certified or  registered  mail  properly  addressed to the other party.
Notices mailed or transmitted  via facsimile shall be directed as follows unless
written  notice of a change of  address  or  facsimile  number has been given in
writing in accordance with this Section:  (x) if to Lender, at 10740 Nall, Suite
230, Overland Park, KS 66211, facsimile number (913) 967-4340,  attn. President;
and (y) if to Borrower, at 8112 Maryland Avenue, Suite 400, St. Louis, MO 63105,
facsimile number (314) 880-1999 attn. President

           In no event shall  interest  (including  any charge or fee held to be
interest by a court of competent  jurisdiction)  accrue to be payable  hereon in
excess  of  the  highest  contract  rate  allowable  by law  at  the  time  such
indebtedness shall be outstanding and unpaid,  and if, for any reason,  interest
in excess of the highest legal rate shall be due or paid,  any such excess shall

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constitute and be treated as a payment on the principal hereof and shall operate
to reduce such  principal by the amount of such  excess,  or if in excess of the
principal indebtedness, such excess shall be waived or refunded to the Borrower.

           This Note shall be construed in accordance with the laws of Missouri.
Any  dispute or cause of action  under this Note shall be resolved by a court of
competent subject matter jurisdiction only in Jackson County,  Missouri.  If any
provisions  hereof are  judicially  determined to be invalid,  then that portion
thereof  which is declared  invalid  shall not affect the  remaining  provisions
hereof.

           Borrower hereby  expressly  acknowledges  that Borrower shall have no
right to set-off  against any amounts due to Lender  under this Note against any
amounts which Lender may owe to Borrower. The obligations of Borrower under this
Note are independent,  and Borrower agrees that any claim for sums due and owing
to Borrower  from  Lender  shall be the  subject of a separate  legal  action by
Borrower against Lender.

           The obligations of the Borrower under this Note are secured  pursuant
to that certain Pledge  Agreement of even date hereof.  Reference is hereby made
to such Pledge  Agreement for a description  of the security  interests  granted
under this Note,  a  description  of  Defaults  under the Pledge  Agreement  and
Lender's remedies upon a Default under the Pledge  Agreement.  Capitalized terms
used  herein  and not  otherwise  defined  herein  are used  with  the  meanings
attributed to them in the Pledge Agreement.

         The Borrower shall reimburse the Lender for any costs, internal charges
and  out-of-pocket  expenses  (including  attorneys'  fees and time  charges  of
attorneys for the Lender,  which  attorneys may be employees of the Lender) paid
or  incurred  by the Lender in  connection  with the  preparation,  negotiation,
execution, delivery, review, amendment,  modification, and administration of the
Loan Documents.  The Borrower also agrees to reimburse the Lender for any costs,
internal charges and out-of-pocket  expenses (including attorneys' fees and time
charges of attorneys  for the Lender,  which  attorneys  may be employees of the
Lender) paid or incurred by the Lender in  connection  with the  collection  and
enforcement  of the Note.  The Borrower  further agrees to indemnify the Lender,
its  directors,  officers and  employees  against all losses,  claims,  damages,
penalties,  judgments,  liabilities and expenses (including, without limitation,
all expenses of litigation or preparation  therefor whether or not the Lender is
a party  thereto)  which any of them may pay or incur arising out of or relating
to this Note, the other Loan Documents, the transactions  contemplated hereby or
the direct or indirect  application  or proposed  application of the proceeds of
the Note except to the extent such  obligations  arise from the gross negligence
or willful misconduct of the Lender.

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         THIS NOTE SHALL BE CONSTRUED IN ACCORDANCE  WITH THE INTERNAL LAWS (AND
NOT THE LAW OF CONFLICTS) OF THE STATE OF MISSOURI.

         THE  BORROWER   HEREBY   IRREVOCABLY   SUBMITS  TO  THE   NON-EXCLUSIVE
JURISDICTION  OF ANY UNITED  STATES  FEDERAL OR MISSOURI  STATE COURT SITTING IN
KANSAS CITY,  MISSOURI IN ANY ACTION OR PROCEEDING ARISING OUT OF OR RELATING TO
ANY LOAN DOCUMENTS AND THE BORROWER HEREBY IRREVOCABLY AGREES THAT ALL CLAIMS IN
RESPECT OF SUCH ACTION OR  PROCEEDING  MAY BE HEARD AND  DETERMINED  IN ANY SUCH
COURT AND  IRREVOCABLY  WAIVES ANY OBJECTION IT MAY NOW OR HEREAFTER  HAVE AS TO
THE VENUE OF ANY SUCH SUIT, ACTION OR PROCEEDING BROUGHT IN SUCH A COURT OR THAT
SUCH COURT IS AN INCONVENIENT FORUM. NOTHING HEREIN SHALL LIMIT THE RIGHT OF THE
LENDER TO BRING  PROCEEDINGS  AGAINST  THE  BORROWER  IN THE COURTS OF ANY OTHER
JURISDICTION.  ANY JUDICIAL PROCEEDING BY THE BORROWER AGAINST THE LENDER OR ANY
AFFILIATE OF THE LENDER INVOLVING, DIRECTLY OR INDIRECTLY, ANY MATTER IN ANY WAY
ARISING OUT OF, RELATED TO, OR CONNECTED WITH ANY LOAN DOCUMENT SHALL BE BROUGHT
ONLY IN A COURT IN KANSAS CITY, MISSOURI.

         THE BORROWER AND THE LENDER  HEREBY WAIVE TRIAL BY JURY IN ANY JUDICIAL
PROCEEDING  INVOLVING,  DIRECTLY OR INDIRECTLY,  ANY MATTER (WHETHER SOUNDING IN
TORT, CONTRACT OR OTHERWISE) IN ANY WAY ARISING OUT OF, RELATED TO, OR CONNECTED
WITH ANY LOAN DOCUMENT OR THE RELATIONSHIP ESTABLISHED THEREUNDER.

           In this Note,  the singular  shall include the plural;  the masculine
shall include the feminine and the neuter genders;  and  "borrower",  "maker" or
"undersigned"  shall include the  Borrower.  All persons  liable,  either now or
hereafter,  for the payment of this Note shall be jointly and severally  liable,
and waive presentment, demand (other than demand for payment as provided above),
protest,  and  notice  of  non-payment  and of  protest,  and  agrees  that  any
modifications  of the terms of payment or extension of time or payment  shall in
no way impair its joint and several liability.

           THE BORROWER AND ANY  ENDORSERS OR  CO-MAKERS,  ALL HEREBY  EXPRESSLY
WAIVE  THE  RIGHT  TO A TRIAL  BY  JURY  IN ANY  CLAIM,  ACTION,  PROCEEDING  OR
COUNTERCLAIM  BROUGHT BY ANY PERSON AGAINST ANY PERSON ON ANY MATTER ARISING OUT
OF OR IN ANY WAY  CONNECTED  WITH THIS NOTE OR THE  RELATIONSHIP  OF THE PARTIES
CREATED THEREUNDER.

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           IN WITNESS WHEREOF,  the duly authorized  representatives of Borrower
have executed this Agreement on the date first above written.

                                             BORROWER:

                                             DTI Holdings, Inc.
ATTEST:                                      a Missouri corporation


By: /s/ Daniel A. Davis                      By  /s/ Gary W. Douglass
   ----------------------------              ------------------------
Name:   Daniel A. Davis                      Name:   Gary W. Douglass
Title:  Vice President and                   Title:  Senior Vice President -
        General Counsel                              Finance and Administration
                                                     and Chief Financial Officer


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