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                                                                 Exhibit 10.16.1

                   AMENDMENTS TO THE MASTER SERVICES AGREEMENT

     The following amendments shall apply to provisions of the MSA and the Terms
and Conditions, Private Line Service Supplements and Credit Requirements
Supplements thereto. "SETTLEMENT AGREEMENT," as used herein, shall refer to the
agreement to which this Schedule 1 is attached. All initially capitalized terms
used but not defined herein will have the same meaning given to such terms in
the MSA.

     1.   RATES AND CHARGES; PROCUREMENT PROCESS. For a period of not less than
five (5) years from the Effective Date of the Settlement Agreement and subject
to the terms contained herein:

     (a)  Supplier shall provide services to UAI at Supplier's *** rates, as set
forth in a pricing schedule, which shall be provided from Supplier to UAI on a
quarterly basis (each, a "PRICING SCHEDULE"). The prices established in a
Pricing Schedule shall be valid for ninety (90) calendar days from the date such
Pricing Schedule is provided to Customer, or until such time as a new Pricing
Schedule is provided to Customer, if later. Any changes to the Pricing Schedule
will not apply to Services that are installed or have been ordered prior to the
effective date of any rate change.

     (b)  Supplier shall provide data pertaining to its On-Net, POP-to-POP
Services ("BROADWING OFFERED SERVICES") for inclusion in the Universal
Information Exchange database on a monthly basis.

     (c)  Customer will provide Supplier with an opportunity to offer service on
100% of the services for which Customer requests a price quote that Customer
believes are Broadwing Offered Services, excluding where Customer has its own
facilities (including the purchase of an indefeasible right of use or similar
arrangement) or Customer's end-user requires the use of a different carrier.

     (i)  If Customer's end-user actually purchases the underlying service and
Supplier's terms and conditions (including technical specifications) are
materially the same as or more advantageous than Customer's alternatives for the
same service, Supplier's services will be selected by Customer if Supplier's
pricing as set forth on the Pricing Schedule is not more than *** greater than
the lowest competitor offer from a carrier that *** ("COMPETITIVE CARRIER").

     (ii) In addition to the foregoing, if the pricing on the Pricing Schedule
is more than *** higher than the lowest competitor offer from a Competitive
Carrier, Customer will offer Supplier the opportunity to offer a revised
(individual case basis) price quote on up to *** of such circuit opportunities
(measured monthly). Supplier will respond to Customer's service

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***  Certain information on this page has been omitted and filed separately with
     the Commission. Confidential treatment has been requested with respect to
     the omitted portions.

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request within 24-hours (or such shorter period as mandated by Customer's
end-user and communicated to Supplier). If Supplier fails to respond within the
required period, Customer may purchase the service from another party without
any liability or further obligation with respect to such transaction. If
Customer's end user actually purchases the underlying service and Supplier's
terms and conditions (including technical specifications) are materially the
same as or more advantageous than Customer's alternatives for the same service,
Supplier's services will be selected by Customer if Supplier's revised
individual case basis pricing is not more than *** greater than the lowest
competitor offer from a Competitive Carrier.

     (d)  In the case of OC-48 and higher speed circuits, and other such
services as the Parties may designate from time to time, (i) the procurement
process will be as set out in subsections (c) and (c)(ii) above, (ii) pricing
shall not be based upon the Pricing Schedule, but shall be provided on an
individual case basis, and (iii) Supplier will respond to Customer's service
request within 48-hours (or such shorter period as mandated by Customer's
end-user and communicated to Supplier).

     (e)  Customer shall provide to Supplier a monthly report, detailing those
instances where Supplier's services were not selected and why. The report will
be substantially in the form of Exhibit A attached hereto. The Parties will also
discuss on a monthly basis challenges or critical issues facing the Parties and
key upcoming business opportunities.

     1.   ELIMINATION OF REVENUE COMMITMENTS. All references to a "revenue" or
"take or pay" commitment in the MSA, including but not limited to (a) Section 27
of the Broadwing Master Service Agreement Terms & Conditions and (b) Section 4
of the Broadwing Private Line Service Supplement, are deleted in their entirety.
Customer will not be obligated to meet any revenue or take or pay commitment
under the MSA.

     3.   PAYMENT TERMS. The late charge for past due invoices contained in
Section 1 of the Terms and Conditions of the MSA is hereby amended to be the
lesser of *** percent (***) per month or the highest percentage permitted under
applicable law for undisputed amounts that are not paid by the applicable due
date if Customer fails to remedy such non-payment within 5 days of receipt of
written notice.

     4.   DISPUTE RESOLUTION. Billing disputes initiated by Customer in
accordance with Section 2 of the Broadwing Master Service Agreement Terms &
Conditions ("DISPUTED CHARGES") will be resolved as follows:

     (a)  Within 20 days of Customer's notice of the dispute, Supplier will use
commercially reasonable efforts to (i) notify Customer in writing of those
individually disputed items it has resolved in Customer's favor and (ii) provide
written documentation to Customer for all unresolved disputes or disputes
Supplier does not resolve in favor of the Customer.

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***  Certain information on this page has been omitted and filed separately with
     the Commission. Confidential treatment has been requested with respect to
     the omitted portions.

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     (b)  Within 40 days of Customer's notice of the dispute, Customer will use
commercially reasonable efforts to (i) notify Supplier in writing of those
individually disputed items to which it agrees with Supplier's determination,
and (ii) provide written documentation to Supplier for all remaining unresolved
disputes and the basis thereof (to the extent not previously provided).

     (c)  Within 60 days of Customer's notice of the dispute, if all Disputed
Charges are not resolved, then remaining Disputed Charges will be escalated to
Supplier's and Customer's senior management level to negotiate the resolution of
such Disputed Charges in good faith for at least a 20 day period. Such period
may be extended by the agreement of both Supplier and Customer.

     (d)  Any dispute or disagreement over the Disputed Charges which is not
settled to the mutual satisfaction of Supplier and Customer within 80 days of
Customer's notice of the dispute (or such longer period as may be mutually
agreed upon) will be settled by binding arbitration in accordance with Section
14 of the Broadwing Master Service Agreement Terms & Conditions.

     (e)  Notwithstanding any other provision to the contrary, 30 days after
Customer submits a notice of a Disputed Charge, either party in its sole
discretion may elect to submit the dispute to binding arbitration in accordance
with Section 14 of the Broadwing Master Service Agreement Terms & Conditions.

     (f)  The dispute resolution process described in this Section 4 will apply
to services provided by Customer to Supplier under the Private Line Agreements.

     (g)  For all disputes unrelated to Disputed Charges, the Parties agree to
work in good faith to resolve such disputes under within 10 days after notice of
any such dispute is provided by a Party. If no resolution is reached within such
timeframe, the dispute shall be escalated to senior management level executives
of the Parties, who shall exercise good faith efforts to resolve such dispute
within twenty 20 days. If no resolution is reached within such timeframe, either
Party may seek arbitration as set forth in Section 14.

     5.   JOINT DEVELOPMENT OPPORTUNITIES. On a quarterly basis, or as
frequently as the Parties mutually agree, the Parties shall meet to discuss
joint development opportunities and other mechanisms for further developing the
relationship between the Parties for mutually beneficial purposes.

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                                    EXHIBIT A
                                  SAMPLE REPORT

                                       4<Page>

                                                                 Exhibit 10.17.1

                                   AMENDMENT 1

THIS AMENDMENT 1 ("Amendment 1") is made and entered into this 19 day February,
2002, by and between Williams Communications, LLC, a Delaware limited liability
company ("Williams") and Universal Access, Inc., a Delaware corporation
("Customer") having it's principal place of business at Sears Tower, 223 S.
Wacker, Suite 600, Chicago, Illinois 60606.

WHEREAS, Williams and Customer are parties to that certain Master Services
Agreement dated October 1, 2001, contract number 01R1966.00 (the "Agreement");

WHEREAS, Williams and Customer desire to amend the Agreement;

NOW, THEREFORE in consideration of the foregoing premises and mutual promises
and covenants of the parties hereto, the receipt and sufficiency of which is
hereby acknowledged, Williams and Customer agree to amend the Agreement as
follows:

1. Section 1.1, Table A is hereby amended to include Schedule 17, Managed
Services.

2. Section 2.3(c), of the Agreement is deleted in its entirety and replaced with
   the following:

   c. In determining whether the annual charges are of a sufficient dollar
   amount to meet Customer's Revenue Commitment, Williams will include the
   monthly recurring charges for Williams' Services. The monthly recurring
   charges for Williams Service(s) (including one month's charge for pending
   circuits prior to their delivery subject to the last sentence of the
   following paragraph), and any charges for any circuit or bandwidth ordered by
   Customer from Williams pursuant to any circuit or bandwidth trade, whether
   directly between the parties or through a broker, and whether any such trade
   is governed by a separate agreement between the parties, shall be considered
   an "Applicable Service". The term Applicable Service shall also include all
   charges and fees associated with any such circuit or bandwidth and any paid
   Deficiency Amounts, (as discounted, if applicable) and any credits to which
   Customer may be entitled pursuant to this Agreement as. well as any amounts
   paid by Customer pursuant to Section 3 of Schedule 17 for Managed Services.
   The foregoing not withstanding, the Applicable Services will not include late
   charges, non-recurring charges, ancillary charges, payment penalties, taxes
   and other government imposed surcharges, payments made by Customer for Third
   Party Services (including but not limited to Third Party Local Access
   Service), amounts paid for Equipment Sales and Travel Expenses associated
   with Managed Services as specified in Attachment 1 to Schedule 17, and
   amounts paid to reimburse Williams for costs paid by Williams to any Third
   Party Provider.

   To the extent that, in any year during the Term of this Agreement, Customer
   fails to have a total aggregate billing of Applicable Services from Williams
   greater than or equal to the Annual Minimum amount applicable to a year,
   Williams shall invoice Customer, on Customer's current or next invoice, and
   Customer hereby agrees to pay, an amount equal to the difference between the
   Annual Minimum amount and the amount of Applicable Services actually
   purchased by Customer (the "Deficiency Amount") for such year. The parties
   agree that the Deficiency Amount represents liquidated damages, and is based
   on Customer's commitment to meet the Annual Minimum amount during each year
   of the Term of this Agreement and Williams' agreement to the discounted
   prices set forth in the Service Schedules attached hereto, which are based
   upon such commitment. Notwithstanding the foregoing, in the event that
   Customer has not taken delivery of an Applicable Service within forty-five
   (45) days after the end of the immediately preceding year, then Williams
   shall not count the monthly recurring charges for Williams' Services as set
   forth in such Service Orders towards Customer's Annual Minimum.

3. Except as specifically amended herein, all the covenants, terms and
   conditions and provisions contained in the Agreement shall remain unchanged
   and in full force and effect.

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                                   AMENDMENT 1

IN WITNESS WHEREOF, the parties have executed this Amendment 1 on the day and
year first set forth above.

UNIVERSAL ACCESS, INC.                       WILLIAMS COMMUNICATIONS, LLC:
/s/ Brian Coderre                            /s/ Robert Traill
-----------------------------------          -----------------------------------
Signature of Authorized                      Signature of Authorized
Representative                               Representative
Brian Coderre                                Robert Traill
-----------------------------------          -----------------------------------
Printed Name                                 Printed Name
Senior VP Carrier Relations                  VP Strategic Sourcing
-----------------------------------          -----------------------------------
Title                                        Title
2-14-02                                      2-19-02
-----------------------------------          -----------------------------------
Date                                         Date

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