<PAGE>

                                                                 Exhibit 10.1.18

                               WARRANT CERTIFICATE

THE WARRANTS REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED UNDER THE
SECURITIES ACT OF 1933 AND MAY NOT BE SOLD OR TRANSFERRED IN THE ABSENCE OF SUCH
REGISTRATION OR AN EXEMPTION THEREFROM UNDER SUCH ACT. SUCH WARRANTS MAY BE
TRANSFERRED ONLY IN COMPLIANCE WITH THE CONDITIONS SPECIFIED IN THE WARRANT
AGREEMENT, DATED AS OF JULY 16,1999, ("WARRANT AGREEMENT") BETWEEN THE ISSUER
AND THE INITIAL HOLDER OF THE WARRANTS THEREIN NAMED, A COMPLETE AND CORRECT
COPY OF WHICH IS AVAILABLE FOR INSPECTION AT THE PRINCIPAL OFFICE OF THE ISSUER
AND WILL BE FURNISHED TO THE HOLDER HEREOF UPON WRITTEN REQUEST AND WITHOUT
CHARGE. THIS WARRANT CERTIFICATE IS NOT TRANSFERRABLE EXCEPT UPON CONDITIONS SET
FORTH IN AND EXECUTION OF THE WARRANT AGREEMENT.

                    EXERCISABLE AT ANY TIME FROM TIME TO TIME

                       UNTIL TERMINATED IN ACCORDANCE WITH

                              THE WARRANT AGREEMENT

No. W-1

                               WARRANT CERTIFICATE

            This Warrant Certificate certifies that General Electric Capital
Corporation (the "Administrative Agent"), or registered assigns, is the
registered holder of 570,600 Warrants (the "Warrants") to purchase shares of
Common Stock of Advanced Telecommunications, Inc., a Minnesota corporation (the
"Issuer"). Each Warrant entitles the holder, subject to the conditions set forth
herein and in the Warrant Agreement, to purchase from the Issuer before 5:00.
P.M., local time, on any business day of the Issuer at any time or from time to
time until terminated in accordance with the Warrant Agreement (the "Expiration
Date"), one fully paid and nonassessable share of the Common Stock of the Issuer
(the "Shares") at a price of $.01 per share (the "Exercise Price"), payable in
lawful money of the United States of America, upon surrender of this Warrant
Certificate, execution of the annexed Form of Election to Purchase and payment
of the applicable Exercise Price at the office of the Issuer at 730 Second
Avenue South, Suite 1200, Minneapolis, Minnesota 55402 or such other address as
the Issuer may specify in writing to the registered holder of the Warrants
evidenced hereby (the "Warrant Office"). The Exercise Price and number of
Warrant Shares purchasable upon exercise of the Warrants are subject to
adjustment prior to the Expiration Date upon the occurrence of certain events as
set forth in Warrant Agreement.

            No Warrant may be exercised after 5:00 P.M., local time of the
Warrant Office, on the Expiration Date and all rights of the registered holders
of the Warrants shall cease after 5:00 P.M., local time of the Warrant Office,
on the Expiration Date.

<PAGE>

            The Issuer may deem and treat the registered holder(s) of the
Warrants evidenced hereby as the absolute owner(s) thereof (notwithstanding any
notation of ownership or other writing hereon made by anyone), for the purpose
of any exercise hereof and of any distribution to the holder(s) hereof, and for
all other purposes, and the Issuer shall not be affected by any notice to the
contrary.

            Warrant Certificates, when surrendered at the office of the Issuer
at the above-mentioned address by the registered holder hereof in person or by a
legal representative duly authorized in writing, may be exchanged, in the manner
and subject to the limitations provided in the Warrant Agreement, but without
payment of any service charge, for another Warrant Certificate or Warrant
Certificates of like tenor evidencing in the aggregate a like number of
Warrants.

            Upon due presentment for registration of transfer of this Warrant
Certificate at the Warrant Office, a new Warrant Certificate or Warrant
Certificates of like tenor and evidencing in the aggregate a like number of
Warrants shall be issued in exchange for this Warrant Certificate to the
transferee(s) and, if less than all the Warrants evidenced hereby are to be
transferred, to the registered holder hereof, subject to the limitations
provided in the Warrant Agreement, without charge except for any tax or other
governmental charge imposed in connection therewith.

            This Warrant Certificate is one of the Warrant Certificates referred
to in the Warrant Agreement dated as of July 16, 1999 between the Issuer and the
Administrative Agent (the "Warrant Agreement"). Said Warrant Agreement is hereby
incorporated by reference in and made a part of this instrument and is hereby
referred to for a description of the rights, limitation of rights, obligations,
duties and immunities thereunder of the Issuer and the holders.


                                       2
<PAGE>

            IN WITNESS WHEREOF, the Issuer has caused this Warrant Certificate
to be signed by its duly authorized officers on this the 19th day of July, 1999.

                                       ADVANCED TELECOMMUNICATIONS, INC.


                                       By: /s/ Michael A. Donchve
                                           -------------------------------------
                                           Name:  Michael A. Donchve
                                           Title: Treasurer

ATTEST:


By: /s/ Richard Smith
    ----------------------------
    Name: Richard Smith
    Title:

<PAGE>

                          FORM OF ELECTION TO PURCHASE

                 [To be executed only upon exercise of Warrant]

            The undersigned registered owner of this Warrant irrevocably
exercises this Warrant for the purchase of __________ shares of Common Stock of
Advanced Telecommunications, Inc., and herewith makes payment therefor, all at
the price and on the terms and conditions specified in this Warrant and requests
that certificates for the shares of Common Stock hereby purchased (and any
securities or other property issuable upon such exercise) be issued in the name
of and delivered to ______________ whose address is ____________________ and, if
such shares of Common Stock shall not include all of the shares of Common Stock
issuable as provided in this Warrant, that a new Warrant of like tenor and date
for the balance of the shares of Common Stock issuable hereunder be delivered to
the undersigned.


                                       _________________________________________
                                       (Name of Registered Owner)


                                       _________________________________________
                                       (Signature of Registered Owner)


                                       _________________________________________
                                       (Street Address)


                                       _________________________________________
                                       (City)          (State)        (Zip Code)

NOTICE:  The signature on this subscription must correspond with the name as
         written upon the face of the Warrant in every particular, without
         alteration or enlargement or any change whatsoever.


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