<Page>

                                                                 Exhibit 10.17.4

                                   SCHEDULE 17
                                MANAGED SERVICES

This Williams Managed Services Schedule ("Managed Services Schedule") is a
schedule to and a part of that Master Services Agreement No. 01R1966.00 ("MSA")
by and between Williams Communications, LLC and Customer. Williams
Communications may designate its affiliate Williams Communications Managed
Services, LLC a wholly owned subsidiary of Williams Communications, LLC to
provide the services set forth herein.

                                 SECTION 1. TERM

TERM OF AGREEMENT. The term of this Managed Services Schedule shall commence on
the Effective Date and shall continue in effect thereafter for the term of the
MSA. Unless Customer is in default, any services being provided at the time of
termination of the MSA shall continue upon the terms and conditions of this
Managed Services Schedule until the end of the term of the applicable Exhibit A.

                           SECTION 2. MANAGED SERVICES

SERVICES TO BE PERFORMED. Williams shall prepare a separate summary of services
to be performed ("Exhibit A") for each Customer request for managed services
("Managed Services"). Each Exhibit A shall be a part of the MSA and this
Schedule and incorporated herein. All Exhibit As shall be sequentially numbered
for ease of identification, e.g., Exhibit A.1, A.2, A.3 and so forth and shall
be executed by authorized representatives of Williams and Customer.

EXHIBIT A. Williams shall provide Managed Services as described in each Exhibit
A, which shall be substantially in the form attached hereto. Each Exhibit A
shall have a term associated with a start and end date for the Managed Services
described. From time to time, changes may be made in the Managed Services in the
nature of additions, deletions or modifications, which changes will be reflected
in an Amendment to the applicable Exhibit A.

EQUIPMENT SALE TERMS AND CONDITIONS. If authorized representatives of the
parties agree in writing that Williams will provide equipment to Customer, the
terms and conditions of Attachment I, "Equipment Sale Standard Terms and
Conditions", attached hereto and incorporated herein, shall apply.

SECTION 3. COMPENSATION AND EXPENSES

RATES AND EXPENSES. Customer shall pay Williams the rate(s) and any actual and
reasonable expenses specified in the applicable Exhibit A for the Managed
Services,.

OFFICE SPACE AND ADMINISTRATIVE SUPPORT. Customer shall supply Williams, ***,
with reasonable office or other space and administrative support to the extent
any Services are performed on Customer's premises.

                             SECTION 4. WORK PRODUCT

          Unless otherwise set forth on an Exhibit A, the parties acknowledge
and agree that any and all ideas, inventions, designs, computer programs,
software enhancements, modules, products and related documentation and other
works of authorship (collectively, the "Developments"), made or conceived solely
by Williams or Customer prior to the performances of Managed Services set forth
in the applicable Exhibit A shall remain the exclusive property of the creating
party. Both parties shall immediately return all Developments owned by the other
party prior to the Effective Date of this Managed Services Schedule, within
seven (7) days of any request by the owning party or upon the expiration or
termination of this Agreement, whichever shall occur first; provided, however,
the receiving party may retain one archival copy, which shall be subject to the
confidentiality provisions set forth in Section 8.6 of the Agreement. Williams
and Customer shall set forth ownership of any Developments developed or created
by Williams and Customer pursuant to an Exhibit A in the applicable Exhibit A.

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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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              Williams Communications - Proprietary & Confidential

<Page>

                                                                 Exhibit 10.17.4
                                   SCHEDULE 17
                                MANAGED SERVICES

                        SECTION 5. INDEPENDENT CONTRACTOR

In its performance under this Managed Services Schedule, Williams shall be an
independent contractor to Customer. The detailed manner and method of performing
the work are under the sole control of Williams. Nothing in this Managed
Services Schedule shall constitute Williams as an employee, licensee, partner or
agent of Customer, and Williams shall not hold itself out as such. Williams
specifically agrees and understands that Williams shall not be entitled to any
of the benefits which are available to Customer employees.

                           SECTION 6. CUSTOMER POLICY

If Managed Services are to be performed on Customer's premises, Williams shall
comply with all Customer policies, including, but not limited to, working hours
and all safety and security regulations and policies in effect at Customer's
facilities. If Customer fails to provide such policies with reasonable advance
notice prior to Williams' entry upon the premises, Williams will be excused from
any failures to meet its obligations hereunder to the extent such failures are
caused by Customer's failure to provide the applicable policies to Williams.

                           SECTION 7. LETTER OF AGENCY

If required, upon the execution of this Managed Services Schedule, Customer
shall give Williams the limited authority to directly notify the appropriate
vendor for the purpose as specifically identified in a letter substantially in
the form of Exhibit B hereto. Customer may terminate this authorization at any
time upon notice to Williams. As soon as commercially practicable, Customer
shall also provide its vendors with a letter (with a copy to Williams)
acknowledging Williams' role as Customer's agent solely as it relates to the
purpose as specifically identified in a letter substantially in the form of
Exhibit B hereto. As soon as commercially practicable, Customer shall provide
Williams with a copy of any contractual commitments between Customer and its
vendor that Williams must be aware of or comply with in order to dispatch such
vendor accordingly.

                               SECTION 8. WARRANTY

     a.  Williams warrants that its Managed Services provided pursuant to this
         Managed Services Schedule will be of a professional quality conforming
         to generally accepted industry standards and practices.

     b.  WILLIAMS MAKES NO OTHER ADDITIONAL WARRANTIES ABOUT THE MANAGED
         SERVICES PROVIDED HEREUNDER, EXPRESS OR IMPLIED, INCLUDING BUT NOT
         LIMITED TO, ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR
         PURPOSE OR USE. WILLIAMS DISCLAIMS ANY WARRANTY TO PREVENT UNAUTHORIZED
         USE OF THE SYSTEM.

     c.  For any breach of the above warranty, Customer's exclusive remedy, and
         Williams' entire liability, shall be the reperformance of the deficient
         Managed Services. In order to receive warranty remedies, deficiencies
         in the Managed Services must be reported to Williams in writing within
         ninety (90) days of completion of those Managed Services. If Williams
         is unable through reperformance to perform the Managed Services as
         warranted, Customer shall only be entitled to recover the fees paid to
         Williams for such deficient Managed Services.

                               SECTION 9. RECORDS

Both parties shall maintain detailed, complete and accurate records of all
expenses related to the Managed Services performed hereunder for a period of at
least two (2) years following the completion of the relevant Managed Services.

                    SECTION 10. NON-SOLICITATION OF EMPLOYEES

During performance of the Managed Services and for a period of one (1) year
following termination of the Managed Services Schedule or completion of the
Managed Services, Customer agrees not to directly solicit, offer, promise
employment to, or employ, in a position similar to the position the person held
with Williams, any of Williams' personnel who perform Managed Services under the
Managed Services Schedule for any reason, unless written consent is received
from Williams. If a Williams employee who has provided service hereunder
voluntarily terminates his or her employment with Williams,

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              Williams Communications - Proprietary & Confidential

<Page>

                                                                 Exhibit 10.17.4
                                   SCHEDULE 17
                                MANAGED SERVICES

Customer shall not solicit, offer, promise employment to, or employ such former
Williams employee for six (6) months from the date of termination of employment.
If a current or former Williams employee as described herein is employed during
the restrictive periods set forth above, Customer shall promptly pay Williams
twenty-five percent (25%) of the employee's base salary for the previous 4
months for expenses associated with replacing and training a new employee and
not as a penalty. Notwithstanding the foregoing, the parties agree that general
solicitation, including without limitation through newspaper advertising or job
fairs shall not be deemed a violation of this provision.

                         SECTION 11. ORDER OF PRECEDENCE

In the event of conflict between the terms in this Managed Services Schedule and
the terms of any Exhibit A, the terms of Exhibit A will prevail. Regarding
purchase and sale of Equipment (as defined in Attachment I), in the event of a
conflict between the terms and conditions of this Managed Services Schedule, the
applicable Exhibit A, and Attachment I, the order of precedence shall be Exhibit
A, then Attachment I, then this Managed Services Schedule.

IN WITNESS WHEREOF, THE PARTIES HAVE INDICATED THEIR AGREEMENT BY SIGNING BELOW.

CUSTOMER:                              WILLIAMS COMMUNICATIONS, LLC:

/s/ Brian Coderre                      /s/ Greg S. Floerke
---------------------------------      ---------------------------------
Signature of Authorized                Signature of Authorized
Representative                         Representative
                                       Greg S. Floerke
---------------------------------      ---------------------------------
Printed Name                           Printed Name
                                       Sr. Vice President
---------------------------------      ---------------------------------
Title                                  Title
December 17, 2001                      December 17, 2001
---------------------------------      ---------------------------------
Date                                   Date

[WILLIAMS COMMUNICATIONS LOGO]

              Williams Communications - Proprietary & Confidential

<Page>

                                   SCHEDULE 17
                            MANAGED SERVICES SCHEDULE

                                  ATTACHMENT I
                                 EQUIPMENT SALE
                          STANDARD TERMS AND CONDITIONS
                                (U.S. SALES ONLY)

1. AGREEMENT: These Standard Terms and Conditions are attached to and made a
part of MSA and Managed Services Schedule (the "Agreement") between Williams and
Customer. Williams shall provide, deliver and, upon Customer request, install
the equipment set forth in the Agreement ("Equipment") and Customer shall pay
the charges computed under this Agreement for the same, all in accordance with
this Attachment I. The Parties have agreed to allocate the risks of the
Equipment's operation between Williams and Customer and this allocation is
reflected in the charges. This Attachment A shall apply to Equipment provided
according to any Exhibit A to the Agreement. ANY DIFFERENT OR ADDITIONAL TERMS
IN ANY PURCHASE ORDER ISSUED BY CUSTOMER ARE AGREED TO BE NULL AND VOID. If
Customer owes any past due amounts to Williams pursuant to the Agreement,
Williams shall have no obligation to place any order for Equipment on behalf of
Customer.

2. PAYMENT: Customer shall pay to Williams one-half of the purchase price of the
Equipment prior to Williams placing the order for the Equipment. Upon delivery
of the Equipment by the vendor, Williams shall invoice Customer the remaining
balance for the Equipment. Except as provided in this Attachment A, Customer
shall remit payment for equipment in accordance with Section 5 of the MSA.
Customer shall pay all Taxes imposed upon the Equipment or the purchase thereof.

3. RISK OF LOSS, TITLE AND SECURITY INTEREST: Title (excluding title to software
products) and risk of loss shall pass to Customer upon delivery of the Equipment
to the site specified in Customer's purchase order. Williams reserves and
Customer grants Williams a security interest in the Equipment in the amount of
the purchase price, less any payments made by Customer pursuant to the
applicable Exhibit A. At Williams option, Customer shall, within five (5) days
of receipt, execute and return to Williams the appropriate financing statements
to fully protect Williams' interest hereunder in accordance with the Uniform
Commercial Code. Notwithstanding the foregoing obligation, Customer hereby
irrevocably appoints Williams as its attorney-in-fact for purposes of executing
and filing such financing statements and such other documents prepared by
Williams or its designated agent for purposes of perfecting Williams' security
interest hereunder. Customer also agrees that this Agreement may be filed by
Williams in any state or local jurisdiction as a financing statement (or as
other evidence of Williams' security interest). Upon receipt of payment,
Williams shall file such financing statements necessary to release its security
interest in the applicable Equipment.

4. LIMITED WARRANTY: Williams warrants that work performed shall be done in a
good and workmanlike manner. The manufacturer's warranty provisions for the
Equipment (including software) shall be extended to Customer. Williams makes no
further warranty of the Equipment. THIS ATTACHMENT EXCLUDES ALL OTHER EXPRESS
WARRANTIES AND ALL IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

5. LIMITATION OF LIABILITY: IN NO EVENT SHALL WILLIAMS OR ITS SUPPLIERS OR
SUBCONTRACTORS BE LIABLE FOR (i) ANY SPECIAL, INCIDENTAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES, (ii) COMMERCIAL LOSS OF ANY KIND (INCLUDING LOSS OF
BUSINESS, PROFITS, DATA, CUSTOMERS, OR USE), OR (iii) ANY DAMAGES OF ANY KIND
RESULTING FROM UNAUTHORIZED USE OF THE EQUIPMENT, REGARDLESS OF WHETHER THESE
DAMAGES ARISE OUT OF AN ACTION IN CONTRACT, TORT OR ANY OTHER LEGAL OR EQUITABLE
THEORY. IN NO EVENT SHALL WILLIAMS' LIABILITY HEREUNDER EXCEED THE AMOUNTS PAID
TO IT HEREUNDER.

6. CUSTOMER DEFAULT: If Customer cancels this order prior to delivery, Williams,
in addition to other remedies available to it at law or in equity, shall be
entitled to receive additional amounts necessary, to cover its reasonable costs,
includingstorage costs and restocking fees incurred by Williams in preparation
for and any actual performance under the Agreement, less amounts already paid.
Williams will promptly refund any amounts previously paid that are in excess of
the amounts necessary to cover such costs. If Customer fails to pay any sums
when due in accordance with the terms of the

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              Williams Communications - Proprietary & Confidential

<Page>

                                   SCHEDULE 17
                            MANAGED SERVICES SCHEDULE

MSA, or otherwise fails to perform any material obligation when required,
Williams, in addition to other remedies available to it at law or in equity,
may: (i) cease installing the Equipment .

7. CLAIMS, QUERIES: No claims in respect of shortages, or discrepancies in or
damage to Equipment will be accepted unless Customer notifies Williams in
writing within ten (10) business days of Customer's receipt of the Equipment at
the site Customer designates on its Purchase Order, unless the manufacturer's
inspection period is shorter (but in any event no less than 5 business days).
Williams shall have no liability with respect to damages or shortages caused by
force majeure events as described in the MSA.

8. ACCESS AND INSTALLATION CONDITIONS; ACCEPTANCE:
a) If Williams installs Equipment at a non-Williams location, Customer shall, at
its own expense, provide and be responsible for all proper environmental
conditions at the installation site (the "Premises"). Customer shall hold
Williams harmless from any liability for injury to wires, conduits, pipes,
mains, sewers or other similar property that is not accurately detailed or
accounted for in Customer supplied prints that could not be avoided by the use
of reasonable diligence by Williams. If any unexpected obstruction alters the
routine underground operations, Customer shall pay for any additional expense
related thereto at Williams' then prevailing item and materials rate.

b) Customer shall permit and arrange full access to the non-Williams Premises
necessary for Williams' representatives to perform the installation Services.
Installation of the Equipment will be performed during the normal working hours
of 8:00 a.m. to 5:00 p.m., Monday through Friday, excluding Williams holidays.
Any delay or downtime resulting from a Customer act or omission shall be the
responsibility of Customer and shall accrue at Williams' prevailing rate. In
addition to access, Customer shall provide a suitable operation environment
(including electrical circuitry, isolated ground, air conditioning, humidity
control, heat and security) per manufacturer's specifications.

c) Customer represents and warrants the non-Williams' Premises and conditions to
be encountered by Williams at non-Williams Premises and in the area where work
is to be performed shall (i) be in compliance with all applicable federal, state
and local laws, rules and regulations related to the subject matter of this
Agreement, (ii) be safe, and (iii) not contain, present, or expose Williams
representatives to hazardous materials or hazardous substances. In the event of
breach of the foregoing, Williams may immediately suspend work until Customer
has corrected such condition(s) at Customer's expense. If Customer does not
correct such condition, it will be Williams' option as to whether to enter the
area in which the unsafe condition exists. Williams' refusal to enter such a
location on the basis of safety will not be deemed a breach of this Agreement or
a default under it and no liability for such a decision will attach, except to
the extent a final determination by a court of competent jurisdiction determines
that such decision was wholly unreasonable under the circumstances.

d) Unless otherwise specified in the applicable Exhibit A, if Williams is unable
to provide full installation, commissioning and maintenance services to
Customer, Williams or Customer shall outsource performance of such services to
an entity which has been certified by the Equipment vendor or original equipment
manufacturer.

9. SOFTWARE LICENSE: Certain manufacturers require the attachment of their own
software license, which may be attached to Exhibit A and incorporated therein.
Customer shall comply with such license. If no such license is attached, then to
the extent authorized by the manufacturers of the Equipment, Williams grants
Customer a non-exclusive, non-assignable, non-transferable license for the
useful life of the Equipment to use the software (including related
documentation) solely to maintain and operate the Equipment, provided Customer:
(i) does not allow any aspect of the software to be disclosed to a third party
without Williams' written consent and makes reasonable efforts to ensure that
its employees are aware of this obligation; (ii) uses the software to operate
the Equipment for Customer's internal business purposes only; (iii) does not
copy any part of the software or related documentation without Williams' consent
and does not attempt to develop any source code from the software; (iv) does not
itself, or by allowing a third party to do so, modify, enhance, reverse
engineer, decompile, disassemble or derive source code from the software; (v)
returns to Williams or erases or destroys any software or related documentation
on any media being recycled or discarded and so certifies to Williams; (vi) does
not use it for any illegal purpose. Customer has no right, title or interest in
the software other than as set forth in this Section.

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              Williams Communications - Proprietary & Confidential

<Page>

                                   SCHEDULE 17
                            MANAGED SERVICES SCHEDULE

10. DOMESTIC USAGE ONLY: Customer shall not export or re-export the Equipment,
any software, or any documentation associated with the Equipment or software
from the fifty (50) states of the United States and the District of Columbia.

Customer hereby agrees to purchase the Equipment and associated software as
described in Exhibit A to the Agreement subject to the Standard Terms and
Conditions above.


CUSTOMER:                                 WILLIAMS COMMUNICATIONS, LLC:

/s/ Brian Coderre                         /s/ Greg S. Floerke
--------------------------------          --------------------------------
Signature of Authorized                   Signature of Authorized
Representative                            Representative
                                          Greg S. Floerke
--------------------------------          --------------------------------
Printed Name                              Printed Name
                                          Sr. Vice President
--------------------------------          --------------------------------
Title                                     Title
                                          February 12, 2002
--------------------------------          --------------------------------
Date                                      Date

[WILLIAMS COMMUNICATIONS LOGO]

              Williams Communications - Proprietary & Confidential

<Page>

                                   EXHIBIT A.1
                            TECHNICAL REVIEW SERVICES

This Exhibit A.1 is subject to that Master Services Agreement (No. 01R1966.00)
and the Managed Services Schedule (collectively the "Agreement") by and between
Universal Access, Inc., a Delaware corporation, (hereinafter referred to as
"Universal Access") and Williams Communications Managed Services, LLC, a
Delaware limited liability company (hereinafter referred to as "Williams
Communications"). Universal Access and Williams Communications hereinafter may
be referred to individually as a "Party" and collectively as the "Parties".

1        PROJECT

Williams Communications will conduct physical and wiring inventory audits at the
twenty-one (21) sites set forth in Section 1.3 below and provide Universal
Access with documentation as to the audit results (the "Project").

1.1      PHYSICAL INVENTORY

Williams Communications shall perform a visual physical inventory site audit.
Unless otherwise requested by Universal Access, such audit is visual only in
order to reduce device handling and avoid service disruption. A visual audit may
limit the gathering of some information such as revision level or the serial
number on cards that cannot be seen without removing it from service. To
expedite the inventory process the Field Engineer will compare the site against
existing Universal Access drawings or records, if available, and note any
discrepancies. The Field Engineer will contact the Universal Access' designated
operational contact once on site and prior to touching any equipment. At each
site the Field Engineer shall perform the following tasks:

         A. Confirmation/update of site contact, location, and access
            information;
         B. Floor plan showing rack numbers, locations, conduit and power
            routing;
         C. Rack elevations showing each device within rack, spacing and cable
            routing;
         D. Device name, model, serial number and cards installed by slot for
            each device;
         E. Digital photographs of front and rear of equipment racks and
            relevant breaker panels;
         F. Power distribution chart showing each breaker, device and feed or
            UPS assignment;
         G. Verification of labeling (racks, equipment, breakers, etc., but not
            data circuits); and
         H. Comments and recommendations on the general site conditions
            (cleanliness, safety, mounting, air flow, cable and fiber
            management, etc.).

1.2      WIRING INVENTORY

Williams Communications shall perform a detailed inventory of a site's wiring to
assist in but not limited to provisioning, recovering underutilized assets, and
streamline troubleshooting. This process can be time consuming for a large
number of circuits, as it requires tracing each data cable at the site. Due to
the nature of some cable management systems, cable tracing is potentially
disruptive. After completion of the wiring inventory, Universal Access shall
receive the following deliverables:

         A. Data wiring diagram (source device port to destination device port
            by circuit ID; including all intervening patch panels);
         B. Documentation of the cable or fiber jumper type, connectors used,
            etc.; and
         C. Verification of circuit labeling

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1.3      UNIVERSAL ACCESS SITE LIST

<Table>
<Caption>
NO.         CITY                  SITE ADDRESS
---------------------------------------------------------------------------------------------------------
<S>         <C>                   <C>
1           Atlanta               55 Marietta Street, Suite 700, Atlanta Georgia 30303
---------------------------------------------------------------------------------------------------------
2           Boston                800 Bolyston Street, Suite 875, Boston, Massachusettes 02199
---------------------------------------------------------------------------------------------------------
3           Cleveland             1501 Euclid Avenue, Suite 400, Cleveland, Ohio 44115
---------------------------------------------------------------------------------------------------------
4           Dallas                1950 N. Stemmons Freeway, Suite 1034, Dallas, Texas 75207
---------------------------------------------------------------------------------------------------------
5           Denver                1850 Pearl Street, Denver, Colorado 80203
---------------------------------------------------------------------------------------------------------
6           Houston               8413 Hempstead Hwy M.P.6.O, Room 1, Houston Texas 77008
---------------------------------------------------------------------------------------------------------
7           Indianapolis          550 Kentucky Avenue, Suite 2, Indianapolis, Indiana 46225
---------------------------------------------------------------------------------------------------------
8           Los Angeles           624 South Grand, Suite 1700, Los Angeles California 90017
---------------------------------------------------------------------------------------------------------
9           Los Angeles           1200 W. 7th Street, Suite L2-240, Los Angeles, California 90017
---------------------------------------------------------------------------------------------------------
10          Miami                 2153-2155 NW 22nd Street, Miami, Florida 33142
---------------------------------------------------------------------------------------------------------
11          New York              60 Hudson Street, Suite 118 and 20th Floor, New York, New York 10013
---------------------------------------------------------------------------------------------------------
12          New York              60 Hudson Street, 4th Floor, New York, New York 10013
---------------------------------------------------------------------------------------------------------
13          PAIX                  529 Bryant Street, Palo Alto, California 94301
---------------------------------------------------------------------------------------------------------
14          Philadelphia          2401 Locust Street, 4th Floor, Philadelphia, Pennsylvania 19103
---------------------------------------------------------------------------------------------------------
15          Phoenix               3300 N. Central Ave, Suite 1550, Phoenix, Arizona 85012
---------------------------------------------------------------------------------------------------------
16          Pittsburgh            3170 Sassafras Way, Pittsburgh Pennsylvania 15222
---------------------------------------------------------------------------------------------------------
17          Raleigh               115 N. Harrington Street, 3rd Floor, Raleigh North Carolina 27603
---------------------------------------------------------------------------------------------------------
18          San Diego             4216 University Avenue, Street 3 and 2, San Diego, California 92105
---------------------------------------------------------------------------------------------------------
19          Seattle               2001 6th Avenue, Suite 2800, Seattle, Washington 98121
---------------------------------------------------------------------------------------------------------
20          Southfield            19675 W. 10 Mile Road, Southfield, Michigan 48078
---------------------------------------------------------------------------------------------------------
21          Washington            1220 L Street NW, Washington DC 20005
---------------------------------------------------------------------------------------------------------
</Table>

2     WILLIAMS COMMUNICATIONS RESOURCES

Williams Communications shall provide project management, engineering and
computer aided design ("CAD") operator services who will perform the services to
complete the Project.

2.1      PROJECT MANAGER

Williams Communications shall provide a single point of contact who will have
responsibility for overseeing the delivery of the Project ("Project Manager").
The Project Manager will coordinate within the specific audit sites with
Universal Access to in order for the site to be ready for the audits to begin
prior to Williams Communications arrival on site to conduct the audit. The
Project Manager shall report regularly to Universal Access the progress of the
Project and potential problem areas that may affect the Project timeline.

2.2      FIELD ENGINEER

Williams Communications will provide engineers to travel to the twenty-one (21)
Universal Access sites, listed in Section 1.2 above, who will conduct the
physical and wiring network audits ("Field Engineer"). The Field Engineers will
gather the information and specifications, compile the data into a final written
report for Universal Access. The Field Engineer will also report regularly to
the Project Manager as to the progress and potential problem areas during the
project timeline.

2.3      CAD OPERATOR

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              Williams Communications - Proprietary & Confidential

<Page>

Williams Communications will provide a CAD operator who will produce detailed
diagrams and drawings of each specific Universal Access site based upon the
input provided by the Field Engineers ("CAD Operator"). Each diagram and drawing
will consist of specific site drawings and wiring diagrams. The CAD Operator
will regularly report to the Project Manager the progress and any potential
problem areas that may affect the Project timelines.

3        FORMAT OF DELIVERABLES

Williams Communications shall prepare and deliver the audit documents in both a
tabbed three-ring binder and electronically via e-mail. Upon request, a CD
version will also be available. The following audit documents shall be provided
to Universal Access:

         A.   Site Drawings will be in AutoCAD (.dwg) format
         B.   Most inventory lists will be in Microsoft Excel (.xls) format
         C.   Site photographs will be in compressed digital (.jpg) format
         D.   Other documentation and analysis will be in Microsoft Word (.doc)
              format
         E.   Other formats, particularly a database structure for inventory,
              may be accommodated upon request

4         UNIVERSAL ACCESS RESPONSIBILITIES

Universal Access is responsible for ensuring that the point of presence
locations are prepared and available for access by Williams Communications or a
designated third party. In the event that Williams Communications or a
designated third party is denied access through no fault of its own, Universal
Access will be charged the applicable hourly rate the Resource and any travel
cost for the denied access visit.

5         PRICING

5.1      PRICING ESTIMATE AND INVOICING

Williams Communications shall charge Universal Access *** to complete the
Project. Universal Access shall pay the invoiced amount within thirty (30) days
of the invoice date.

5.2      HOURLY LABOR RATES

Williams Communications will provide skilled personnel to perform the functions
described in the previous sections according to the following schedule:

<Table>
<Caption>
                    --------------------------------------------
                    RESOURCE                  HOURLY RATE
                    --------------------------------------------
                    <S>                                     <C>
                    Project Manager                         ***
                    --------------------------------------------
                    Field Engineer                          ***
                    --------------------------------------------
                    CAD Operator                            ***
                    --------------------------------------------
</Table>

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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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              Williams Communications - Proprietary & Confidential

<Page>

6       TERM

This Exhibit A.1 shall commence on December 17, 2001 and remain in force for the
greater of six (6) months or the completion of the Project.

         IN WITNESS WHEREOF, the parties have executed this Exhibit A.1 as of
the date first above written by a representative empowered to bind that party
with respect to the undertakings and obligations contained herein:


UNIVERSAL ACCESS, INC.:                       WILLIAMS COMMUNICATIONS, LLC:

/s/ Antonio Daniels                           /s/ Greg S. Floerke
--------------------------------              --------------------------------
Signature of Authorized                       Signature of Authorized
Representative                                Representative
Antonio Daniels                               Greg S. Floerke
--------------------------------              --------------------------------
Printed Name                                  Printed Name
VP of Engineering                             Sr. Vice President
--------------------------------              --------------------------------
Title                                         Title
December 17, 2001                             December 17, 2001
--------------------------------              --------------------------------
Date                                          Date

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              Williams Communications - Proprietary & Confidential

<Page>

                                   EXHIBIT A.2
                               CONSULTING SERVICES

This Exhibit A.2 is subject to that Master Services Agreement (No. 01R1966.00)
and the Managed Services Schedule (collectively the "Agreement") by and between
Universal Access, Inc., a Delaware corporation, (hereinafter referred to as
("Universal Access") and Williams Communications Managed Services, LIC, a
Delaware limited liability company (hereinafter referred to as "Williams
Communications"). Universal Access and Williams Communications hereinafter may
be referred to individually as a "Party" and collectively as the "Parties".

 1.      PROJECT
Williams Communications will provide engineering consulting services to
Universal Access to assist in their existing ATM network ("Engineering
Services"). Universal Access is migrating new network facilities into their
existing ATM topology. The actual services provided will be adjusted for
consistency and compatibility with the requirements, design and acceptance lest
criteria established in the design phase.

2.       ENGINEERING ARCHITECT SERVICES
Williams Communications will provide engineering architect expertise to assist
Universal Access in the design and migration of new network facilities into
their existing ATM network platform. Universal Access is responsible for
providing adequate office space with amenities (telephone, data lines, fax
machine, desk space, etc.) for each person assigned. This office space should
afford a level of privacy so each individual is able to conduct day-to-day
operations directly related to their Williams Communications employment
activities. Upon Williams Communications ATM engineering architect and
provisioning engineering architect arriving at Universal Access' site, Universal
Access shall have made arrangements for any and all resources which shall
include without limitation Universal Access employees, Aleron personnel and
information necessary to complete the Engineering Services set forth herein.

3.       ATM ENGINEERING ARCHITECT
Williams Communications will provide one ATM network architect at Universal
Access' premises for a period estimated to be sixty (60) days. Williams
Communications will provide the following services in conjunction with Universal
Access stall relating to the development and expansion of the Universal Access
ATM network.

         3.1 Product Specification The service offerings, service level goals
         and traffic level expectations of the network will be identified with
         Universal Access and documented in detail. Key metrics, such as peak
         acceptable utilization, port density, and expansion rules will be
         identified and itemized. Where detailed traffic assumptions are not
         available, Williams Communications will work with Universal Access to
         establish a mutually agreed upon baseline set of assumptions from which
         all technical and economic decisions will be made. The product
         specification will be based on Universal Access product definition, the
         ATM Engineer will provide feedback to Universal Access on their current
         product definition.

         3.2 Network Design -- A network design will be prepared that builds on
         the existing Universal Access network to deliver the specific product
         features identified in the Product Specification. Deliverables include
         recommendation on hardware expansion, network capacity, and
         interconnects to the Williams Communications ATM network. The target
         date for network interconnection between Williams Communications ATM
         network and Universal Access ATM network is April 15, 2002.

4.       PROVISIONING ENGINEERING ARCHITECT
Williams Communications will provide one (1) provisioning engineering architect
at the Universal Access' premise for a period estimated to be thirty (30) days.
Williams Communications will provide services in conjunction with Universal
Access staff relating to the business applications and processes of establishing
the provisioning processes associated with the telecommunications and industry
accepted back office support system. Williams Communications will assist in
developing specific procedures, processes and workflows associated with the
provisioning applications to be used within the Universal Access ATM network.
The establishment of these procedures may include circuit ordering, circuit
testing, site acceptance processes, and office support system integration. Any
adjustments made during the process planning period will be applied uniformly
across all provisioning procedures. Williams Communications will prepare a
detailed description of test functions.

5.   PRICING

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Williams Communications pricing is for providing one (1) ATM engineer consultant
and one (1) provisioning engineer consultant for the period of lime described in
Section 2.1 and 2.2 above,

<Table>
             <S>                                                    <C>
             TOTAL MONTHLY RATES*
             ATM Engineering Architect per month                    ***
             Provisioning Engineering Architect per month           ***

             TOTAL ESTIMATED RATES:

             ATM Engineering Architect (two (2) months)             ***
             Provisioning Engineering Architect per month           ***
                           TOTAL                                    ***
</Table>

Williams Communications shall charge Universal Access *** for the Services set
forth herein. Williams Communications shall invoice Universal Access on a
monthly basis in arrears.

6.   TERM

This Exhibit A.2 shall commence on the date signed by the last party ("Effective
Date") and remain in effect for three (3) months from the Effective Date or
completion of the Project whichever occurs last ("Initial Term"). The term of
this Exhibit A.2 can only be altered in subsequent writing by authorized
representatives of Universal Access and Williams Communications.

     IN WITNESS WHEREOF, the parties have executed this Exhibit A.2 as of the
date written below by a representative empowered to bind that party with respect
to the undertakings and obligations contained herein:

UNIVERSAL ACCESS, INC.                        WILLIAMS COMMUNICATIONS, LLC:

/s/ Antonio Daniels                           /s/ Greg S. Floerke
--------------------------------              --------------------------------
Signature of Authorized                       Signature of Authorized
Representative                                Representative
Antonio Daniels                               Greg S. Floerke
--------------------------------              --------------------------------
Printed Name                                  Printed Name
VP of Engineering                             Sr. Vice President
--------------------------------              --------------------------------
Title                                         Title
February 14, 2001                             February 15, 2002
--------------------------------              --------------------------------
Date                                          Date

----------
*** 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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<Page>

                                   EXHIBIT A.3
               PROJECT MANAGEMENT, ENGINEERING, AND IMPLEMENTATION
This Exhibit A.3 is subject to that Master Service Agreement (No. 01R1966.00)
and the Managed Services Scheduled (collectively the "Agreement") by and between
Universal Access, Incorporated, a Delaware corporation, (hereinafter referred to
as ("Universal Access") and Williams Communications Managed Services, LLC, a
Delaware limited liability company (hereinafter referred to as "Williams
Communications"), Universal Access and Williams Communications hereinafter may
be referred to individually as a "Party" and collectively as the "Parties".

     1.  Project

Williams Communications will remove Universal Access' ATM equipment sites and
ship such equipment to Williams Communications St. Louis facility ("Project").

Throughout the Project, Williams Communications will provide project management
services to obtain approvals at key Project milestones, keep Universal Access
management informed of Project status, deal with exceptions, help manage costs
and timeline.

     2.  Project Management

Williams Communications and Universal Access will each assign key personnel
making up the leadership team for the Project and mutually agree upon technical
and financial approval mechanisms. In addition, Williams Communications will
provide other project management, technical and operations personnel as
determined necessary by mutual written agreement of each Party in order to meet
the demands of the Project. For the duration of this Project, Universal Access
will provide a single point of contact to Williams Communications with Project
authorization and sign-off authority. Williams Communications will use
established project management methods and techniques to plan and control the
Project. In conjunction with these tools, Williams Communications will establish
the following baseline documents at the beginning of the Project and maintain
such documents throughout the Project life cycle.

         A. WORKFLOW PROCESSES - Williams Communications will prepare order and
         approval processes unique to Universal Access and its vendor/partner
         combination to facilitate smooth order flow and Project tracking.
         Williams Communications will establish lead times,
         scheduling/notification, configuration management and documentation
         flow will be established between Universal Access, its vendor(s),
         Williams Communications, LLC network services, other network providers
         and other subcontractors including without limitation site survey,
         wiring or installation.

         B. TASK TIMELINE AND KEY MILESTONES - Williams Communications will
         prepare and maintain a detailed Project schedule, assigning tasks to
         Project resources along with mutually agreed upon due dates. The key
         milestones will be set at the beginning of the Project and will be used
         to update Universal Access's management on the progress of the
         activities related to key dates.

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         C. PROJECT BUDGET - Williams Communications will work with Universal
         Access to provide a complete headcount forecast as well as a capital
         and recurring expense budget for each phase of the Project. The Program
         Manager will maintain the budget and raise issues for resolution by
         Universal Access.

         D. PROJECT REVIEWS - Williams Communications and Universal Access will
         conduct regular Project reviews as listed below with the suggested
         frequency or as needed. The purpose of these reviews is to facilitate
         the regular exchange of information between Williams Communications and
         Universal Access, providing a forum for the identification, escalation
         and resolution of issues affecting the Project.

         E. REMOVAL STATUS REVIEW - On a weekly basis, the Project Manager shall
         review the implementation performance against the schedule; exchange
         information affecting schedule performance; and identify and reach an
         agreement with Universal Access on required actions.

         F. ISSUES LOG - All action items and issues resulting from project
         review activity will be logged and tracked through resolution by the
         Williams Program Manager.

3.       Equipment Removal
Williams Communications will remove the Universal Access equipment from the
specified sites according to the Universal Access provided requirements to
include the following activities:

         A. FACILITIES PREPARATION - Universal Access shall ensure that power to
         the equipment to be removed has been turned off at the circuit breaker
         box ("CBB") and that the equipment is ready for removal. Williams
         Communications can arrange for the power at the CBB to be turned off,
         if authorized in writing by the Universal Access. Williams
         Communications removal of associated data cabling is included in this
         Exhibit A-3. If requested in writing by Universal Access, Williams
         Communications will prepare on-site surveys before the equipment
         removal at an additional cost. Williams Communications will submit a
         planned network maintenance plan ("PNMP") document for each site to
         schedule and coordinate the equipment, power connection, and jumper
         removals from the site as required.
         B. CIRCUIT REMOVAL ORDERS - Circuit disconnection orders are not
         included in this proposal. Universal Access will need to place orders
         with Williams Communications, LLC Network Services, third party
         carriers or LECs as necessary so that the circuits are disconnected
         prior to the scheduled equipment removal. William Communications can
         request the circuit disconnection orders as authorized by the Universal
         Access at an additional cost.

         C. EQUIPMENT REMOVAL - Prior to the scheduled equipment removal date at
         each site, Universal Access will provide a list of all equipment to be
         removed from each site, which will include without limitation the
         equipment manufacturer, model number and exact location. Williams
         Communications will disconnect the power cables and jumpers from the
         Universal Access equipment. Williams Communications will removed the
         equipment from racks, inventory the equipment, and box or crate the
         equipment for shipment. Racks and power cables are to remain in the
         facilities unless otherwise authorized in writing by the Universal
         Access. Williams Communications will complete all work in accordance
         with Williams Communications' standards unless otherwise specified in
         writing by Universal Access.

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         D. INVENTORY - Williams Communications will inventory the equipment as
         it is removed. Williams Communications will provide Universal Access an
         inventory list for each site.

         E. SHIPMENT AND STORAGE - Williams Communications will label the crated
         equipment for pick up and arrange for the common carrier to pick up the
         equipment from each site. Equipment will be shipped to the location
         designated by Universal Access. In the event that Williams
         Communications is ready to ship the equipment and Universal Access is
         not ready to receive the equipment, additional charges for storage may
         apply.

4.       Pricing Estimate

         4.1 PRICING ESTIMATE
         Williams Communications pricing estimate is based on sixty-nine (69)
         chassis of ATM equipment and are based upon the configuration supplied
         by Universal Access. Williams Communications labor rates for the
         Project are set forth in the table in Section 4.2 below. Williams
         Communications shall invoice Universal Access the actual number of
         hours services were performed in arrears on a monthly basis.

<Table>
<Caption>
           ACTIVITY                              PRICING ESTIMATE
           ---------------------------------------------------------------------
           <S>                                   <C>
           Project Management                    ***
           ---------------------------------------------------------------------
           Equipment Removal                     ***
           ---------------------------------------------------------------------
           Estimated Packing and Shipping        ***
           ---------------------------------------------------------------------
           PROJECT PRICING ESTIMATE              ***
           ---------------------------------------------------------------------
</Table>

         4.2 HOURLY RATES FOR SITE RELOCATION, UPGRADES AND CLEAN UP
<Table>
<Caption>
         RESOURCE          HOURLY RATE       OVERTIME HOURLY   HOLIDAY RATE
         --------          -----------       ---------------   ------------
         <S>               <C>               <C>               <C>
         Project Manager   ***               ***               ***
         Technician.       ***               ***               ***
</Table>

         4.3 MISCELLANEOUS HARDWARE
         In addition to the resources set for above, Williams will provide
         cables, cable management and miscellaneous hardware at ***.

         4.4 SHIPPING AND STORAGE
         All shipping and storage shall be via Williams Communications'
         determined best way, insured at Universal Access' net cost in
         manufacturer's original packaging unless otherwise requested in
         writing. Williams Communications shall charge Universal Access for
         shipping and storage at ***.

         4.5 TRAVEL AND EXPENSES
         Williams Communications shall charge Universal Access at ***. These
         cost include but are not limited to airfare, lodging, transportation,
         meals, cell phone charges and long distance phone expenses.

----------
*** 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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              Williams Communications - Proprietary & Confidential

<Page>

5.       Term
This Exhibit A.3 shall commence on the date signed by the last party ("Effective
Date") and remain in effect for six (6) months from the Effective Date or
completion of the Project whichever occurs last ("Initial Term"). The term of
this Exhibit A.3 can only be altered in subsequent writing by authorized
representatives of Universal Access and Williams Communications.

         IN WITNESS WHEREOF, the parties have executed this Exhibit A.3 as of
the date written below by a representative empowered to bind that party with
respect to the undertakings and obligations contained herein:

UNIVERSAL ACCESS, INC.               WILLIAMS COMMUNICATIONS MANAGED
                                     SERVICES, LLC


 By:          /s/ Jay E. Carlson      By:         /s/ Greg S. Floerke
          -------------------------           -------------------------

 Printed                              Printed
 Name:        Jay E. Carlson          Name:     Greg S. Floerke
          -------------------------           -------------------------

 Title:       Chief Technology        Title:    Sr. Vice President
              Officer
          -------------------------           -------------------------

 Date:        May 29, 2002            Date:           June 4, 2002
          -------------------------           -------------------------

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Williams Communications - Proprietary & Confidential