<Page>

                                                                    Exhibit 10.6

                                                           Agreement No. 4569177
                                                           Amendment No. 5
                                                           Page of 8

                                                ACCEPTANCE SHALL BE INDICATED BY
                                                SIGNING AND RETURNING DUPLICATE


TO:                                          FROM:

PF.Net Corp.                                 AT&T Corp.
2941 Fairview Park Dr.                       1200 Peachtree Street
Suite 200                                    Room 09E30
Falls Church, Va. 22042                      Atlanta, GA  30309
Attn:   Donald L. Branscome                  Attn: Lynn O. Pardue


General Purchase Agreement Number 4569177 ("Agreement") between AT&T Corp.
("Company") and PF.Net, Corp. ("PFN") dated October 29,1999 and as modified by
Amendment Nos. 1, 2, 3 and 4 is further modified by Amendment Number 5 as
follows:


1.       FIRST WHEREAS PARAGRAPH OF AGREEMENT: The last five words of the
         paragraph as set forth as follows are deleted from this Agreement:

                  Deleted: "along with certain marketing arrangements".

2.       ARTICLE 1.24: DEFINITION OF DISPOSITION FIBERS: This clause is hereby
         deleted from this Agreement in its entirety.

3.       ARTICLE 1.30: DEFINITION OF MARKETING AGREEMENT: This clause is hereby
         deleted from this Agreement in its entirety.

4.       ARTICLE 3.3.G(v): OWNERSHIP OF SYSTEM: Sub-paragraph (v) is hereby
         deleted from this Agreement in its entirety.

5.       ARTICLE 3.7: MARKETING OF FIBER: This clause is hereby deleted from
         this Agreement in its entirety and is not replaced.

6.       ARTICLE 10.4: SPECIAL PAYMENT TERMS: This clause is hereby deleted from
         this Agreement in its entirety.

7.       ARTICLE 3: STATEMENT OF WORK FOR THE SUPPLY OF LINK(S): The following
         language is added to the Agreement as new Sections 3.1.V through
         3.1.AD:

                  3.1.V For Page 19, Link 14 of Exhibit B of the Agreement,
         Amendment 3, the Builder Substantially Complete Date and Builder
         Compete Date are modified as follows:

                    BUILDER SUBSTANTIALLY COMPLETE DATE:


                             AT&T / PFN Proprietary
12/05/01
<Page>

                         FROM:     September 30, 2001

                         TO:       June 30, 2003

                    BUILDER COMPLETE DATE:

                         FROM:     March 31, 2002

                         TO:       December 31, 2003

         In order to accomplish the requested delay in delivery and minimize the
         cost of work performed in 2002, AT&T and PFN agree that the credit due
         AT&T in the amount of Two Hundred Fifty Thousand Dollars ($250,000.00)
         associated with OA construction shall be retained by PFN to satisfy
         obligations associated with this delay which includes PFN's obligations
         for sales to third parties.

         3.1.W. For Link 14 during 2002, the limit of expenditure by AT&T to PFN
         will not exceed Five Million Dollars ($5,000,000) for work performed in
         2002.

         3.1.X For Link 14, the location for the Santa Ana POP is revised to
         1241 West Alton Avenue at an increase to the price for Link 14 of
         Thirty Five Thousand Dollars ($35,000.00). The Long Beach POP will be
         fiber to the handhole at the POP only with no increase in price to AT&T
         to be charged by PFN.

         3.1.Y With respect to Links 4 and 6, the parties acknowledge that a key
         precedent to completion is an agreement with the Florida Turnpike. If
         an Agreement with the Florida Turnpike cannot be completed by AT&T
         prior to June 30, 2002, then PFN shall have the right to cancel its
         obligations for Links 4 and 6 and submit an invoice for work performed
         through the date of cancellation plus any reasonable actual costs for
         cancellation and/or demobilization charges, as evidenced by
         documentation with the invoices on Links 4 and 6.

         3.1.Z Link 6, Ellisville to Orlando, PFN is authorized to trench or
         bore two (2) one point nine inch (1.9") HDPE ducts as required from the
         Florida Turnpike bore to the existing stub-out piping located outside
         of the existing AT&T Windermere POP on the existing underground
         building wall. PFN will bore one (1) six inch (6") steel pipe from AT&T
         Windermere property across Florida Turnpike to east edge of ROW located
         next to Royal Vista Subdivision. Upon acceptance by AT&T, AT&T will pay
         within thirty (30) days of receipt of an invoice from PFN in an amount
         not to exceed of Forty Thousand Five Hundred Dollars ($40,500.00) for
         this completed work. In the event, PFN determines that the old six inch
         (6") steel casing pipe under Florida Turnpike can be used, AT&T will
         receive a invoice in the amount of Seventeen Thousand Dollars
         ($17,000.00) which represents a credit to AT&T of Twenty-Three Thousand
         Five Hundred Dollars ($23,500.00).

         3.1.AA Link 4 (Orlando FL to Miami, FL)

         (i)      Link 4B, Ft. Pierce to Miami-PFN to install two (2) one point
                  nine inch (1.9") HDPE ducts and pull a new fiber cable for the
                  connection from AT&T

<Page>

                  handhole on Florida Turnpike at Glades Road to the new AT&T
                  Boca Raton POP at 210 Street South and return to a new
                  handhole adjacent to the Florida Turnpike. AT&T will provide
                  the required cable to PFN for this additional work. The
                  increase in the price for Link 4B for this work to AT&T will
                  not exceed Three Hundred Twenty-Three Thousand Two Hundred
                  Dollars ($323,200.00) for this additional construction. This
                  work shall not commence prior to March 31, 2002. If the work
                  does begin prior to that time, AT&T will not be liable for any
                  of the costs associated with that work. AT&T has the option to
                  cancel this additional work in the event the decision can be
                  confirmed that allows AT&T to continue use of the existing
                  AT&T Boca Raton POP adjacent to the Florida Turnpike.

         (ii)     For Link 4, PFN will deliver As-built drawings of this Link
                  including those sections using existing AT&T duct. AT&T's
                  increased cost will be One Hundred Fifty Dollars ($150.00) per
                  mile for one hundred sixty three (163) miles for a total
                  amount not to exceed Twenty-Four Thousand Four Hundred Fifty
                  Dollars ($24,450.00) which will be paid by AT&T within thirty
                  (30) days upon receipt of an invoice after deliver and
                  acceptance of the As-built drawings.

         (iii)    For Link 4B, PFN will require safety precautions to be
                  provided by Florida State Police to close the traffic lane
                  closest to the location of the existing duct structure from
                  Fort Pierce to Miami. AT&T will pay PFN Five Hundred
                  Twenty-Eight Dollars ($528.00) per mile for one hundred
                  thirty-six (136) miles for an estimated total of Seventy-One
                  Thousand Eight Hundred Eight Dollars ($71,808.00) for this
                  required safety precaution.

          3.1.AB BALTIMORE, MD. On Link 38, PFN is authorized by AT&T to make an
         additional build for AT&T and PFN from the backbone past the PFN's 1401
         Russell Street POP to the "AT&T 323 Charles Street POP" for a an
         estimated distance of ten thousand nine hundred four (10,904) feet. For
         this additional build, AT&T authorizes PFN to construct in a single
         ditch to include two (2) six (6") inch steel ducts with two (2) one
         point nine (1.9") inch OD and one (1) one point two five (1.25") inch
         ID innerducts in each ending at the PFN 1401 Russell Street POP
         continuing on to the 323 Charles Street POP. All ducts will be encased
         with 3000 psi strength concrete that will conform to the City of
         Baltimore specifications to provide mechanical protection in lieu of
         diversity. The schedule for completion of this additional work is
         subject to finalizing the required permits and arrangements for special
         safety procedures to be required during construction. The construction
         is estimated to be completed one hundred twenty (120) days following
         the reception of the required permits. For the additional build as set
         forth in this Section 3.1.AB and Exhibit B, there will be no additional
         cost to AT&T.

         3.1.AC Link 37, Atlanta to Greensboro:

         (i)      AT&T authorizes PFN to install the fiber cable where it
                  reaches a POP to pass through said POP using a routing which
                  is internal to the POP building and accomplishes the objective
                  of providing a continuous path for the

<Page>

                  cable to transit from the incoming manhole to the outgoing
                  manhole. Additionally, PFN will deliver as built drawings of
                  the Charlotte to Greensboro portion of Link 37, AT&T's
                  additional cost will be One Hundred Fifty Dollars ($150.00)
                  per mile for a total of four hundred seventy-eight (478) miles
                  for an amount not to exceed Seventy-One Thousand Seven Hundred
                  Dollars ($71,700.00) which will be due within thirty (30) days
                  of receipt of an invoice from PFN after delivery and
                  acceptance of the As-Built drawings by AT&T.

         (ii)     AT&T authorizes PFN to install a fiber cable in a spare duct
                  that currently exists between Atlanta Eastpoint and Atlanta
                  Peachtree POPs. This fiber cable will contain a minimum of
                  thirty-six (36) to forty-eight (48) single-mode fibers for
                  AT&T's sole use which are to be provided to AT&T and charged
                  at PFN's actual cost of that cable. The total fiber count in
                  the fiber cable should include ninety-six (96) TrueWave RS
                  fibers for AT&T which will be paid for by AT&T in this special
                  case and up to one hundred forty-four (144) TrueWave RS fibers
                  for PFN's use at PFN's expense. PFN agrees that it will
                  complete the new build with six (6) ducts as set forth in
                  Exhibit B on a diverse route and have this segment completed
                  by March 31, 2002. All three (3) of the AT&T ducts will be
                  left vacant, and the cable placed in the spare duct with the
                  special cable specified above will remain in service. If for
                  any reason other than reasons of Force Majuere as set forth in
                  Article 37, PFN is unable to complete this c onstruction of
                  the six (6) ducts on a diverse route on or before December 31,
                  2002, the installed fiber cable will revert one hundred (100%)
                  percent to AT&T, and PFN's use of the spare duct will no
                  longer be allowed. For purposes of Agreement, diverse route
                  will be defined as set forth in Exhibit E: Engineering and
                  Construction Requirements.

         3.1.AD Link 39, Philadelphia to Newark, the backbone route will only
         pass the POP at Camden on the opposite side of the street for route
         diversity and the backbone route will only pass the New Brunswick POP
         due to AT&T change in POP plans at no additional cost to AT&T.

8.       ARTICLE 3.6.C: ELECTRICAL POWER FOR OA SITES: Article 3.6.C is deleted
         in its entirety from the Agreement and substituted with the following
         language.

         3.6.C ELECTRICAL POWER FOR OA SITES: After expiration of the three (3)
         year period in which items (i) through (v) of Section 3.6.O are
         provided by PFN at the fixed unit price, PFN will charge AT&T
         negotiated rates for electrical power and building services. AT&T will
         have the option at any time during the term of this Agreement to
         provide its own electrical power upon giving ninety (90) days written
         notice to PFN of AT&T's intention to provide its own power. AT&T and
         PFN agree in the case where AT&T wants to provide its own standalone
         emergency generator it will do so for $2000 per site for a pad nearby
         the existing PFN standby generator and follow the same path for the
         power to travel through the PFN power building and into the AT&T
         buildings. The cost for installing the pad and the generator, plus
         required power cable connections, will be at AT&T's expense.

<Page>

9.       ARTICLE 29: OTHER BUILDER COVENANTS, REPRESENTATIONS AND WARRANTIES:
         The last paragraph of Section 29.8, as added to this Agreement in
         Amendment No. 2, is amended to include the words "and Link 14" after
         the words "ADDED LINKS PRIMARY CITIES". The last paragraph of 29.8 will
         now read as follows:

                  "The Links listed in the following table titled ADDED LINKS
                  PRIMARY CITIES and Link 14, will not be considered in
                  determining the Builder Substantially Complete Date for the
                  last Link for the purposes of this Section 29.8; it being the
                  understanding that the Builder Substantially Complete Dates
                  for said Links, whenever they occur, will not be used in any
                  way to prohibit the sale of the Common Stock of Parent by Koch
                  Ventures, John Warta and Stephen Irwin."



<Table>
<Caption>
                       ADDED LINKS PRIMARY CITIES
-------------------------------------------------------------------------
LINK           TERMINATION A                TERMINATION Z
-------------------------------------------------------------------------
<S>        <C>                            <C>
 1A        Pine Springs, VA (Reroute)     Calverton VA (Reroute)
-------------------------------------------------------------------------
 4         Windermere, FL                 Fort Pierce, FL (Splice Point)
-------------------------------------------------------------------------
 6         Ellisville, FL                 Orlando, FL (through Windermere
-------------------------------------------------------------------------
 37        Atlanta, GA                    Greensboro, NC
-------------------------------------------------------------------------
 38        Arlington, VA                  Philadelphia, PA
-------------------------------------------------------------------------
 39        Philadelphia, PA               Newark NJ
-------------------------------------------------------------------------
 43        Chicago, IL                    Elkhart, IN
-------------------------------------------------------------------------
 44        Toledo, OH                     Cleveland, OH
-------------------------------------------------------------------------
</Table>


10.      MAINTENANCE SERVICES TO PFN AND TO THIRD PARTIES: The following
         paragraphs 6, 7, 8 and 9 from Exhibit C of the Agreement are hereby
         deleted and added to this Agreement as Article 39.1 through 39.4:

"ARTICLE 39: MAINTENANCE SERVICES TO PFN AND TO THIRD PARTIES.

39.1     COVERAGE PERIOD. Maintenance will be performed by AT&T or its
         successors or assigns for all Links described in Exhibit A, and
         conclude upon expiration or termination of the Agreement.

39.2     SUBCONTRACTING. AT&T may subcontract any maintenance activities as set
         forth in Exhibit C, provided that AT&T shall require the
         subcontractor(s) to perform in accordance with the Agreement and
         Exhibit C. The use of any such subcontractor shall not relieve AT&T of
         any of its obligations herein.

39.3     FEES AND COSTS. During any time after the Acceptance Date for any
         Segment of a Cable System, AT&T shall provide for all maintenance
         activity for all Links for which maintenance responsibility is assigned
         to AT&T pursuant to the provisions of this Article 39 and Exhibit C.

         39.3.A. PFN will pay AT&T an monthly fee of FORTY ONE DOLLARS AND SIXTY
         SEVEN

<Page>

         CENTS ($41.67) PER ROUTE MILE OR FIVE HUNDRED DOLLARS ($500.00) PER
         ROUTE MILE ANNUALLY for all maintenance activity described in Exhibit C
         of this Agreement, with the exception of emergency restoral activity as
         set forth in Section 1.3 or PCA work in Section 1.2 of Exhibit C which
         will be billed as needed on a time and material basis according to the
         parties' interests in the Fiber, Conduit or other property affected
         with labor charges not to exceed one thousand dollars ($1,000.00) per
         hour. Any fees and costs for emergency restoral paid to AT&T by
         responsible parties assessed for damages to the System will be
         reimbursed by AT&T to PFN at a rate of thirty-seven and one-half
         percent (37.5%) of the total fees paid to AT&T, less legal and
         administrative costs incurred by AT&T while participating in any damage
         claim or settlement related to cable or conduit damage by responsible
         parties. In the case of any decrease of ten percent (1 0%) or more
         versus the first year forecasted costs of AT&T, an adjustment to
         reflect said decrease will be made to PFN.

         In addition to the paragraph above, PFN will receive an equitable
         offset for any routine services provided by PFN that would otherwise be
         provided by AT&T (For example if PFN does routine ROW clearing, the fee
         will be adjusted to reflect the services performed).

         Effective with the Acceptance Date for each Link, maintenance fees are
         due and payable on a monthly basis until the monthly payment dated of
         December 1, 2003 for all Links for which Acceptance has occurred.
         Thereafter, maintenance fees for all Accepted Links are due and payable
         annually beginning with January 1, 2004.

         39.3.B. Maintenance fees for dark fibers and conduit sold or exchanged
         to third parties (exclusive of emergency restoral fees), will be shared
         as follows: fifty percent (50%) to PFN and fifty percent (50%) to AT&T,
         but such fees shall not be less than the following:


<Table>
<Caption>
-------------------------------------------------------------------------
   NUMBER OF FIBERS SOLD PER SALE               MINIMUM FEE
-------------------------------------------------------------------------
<S>                                   <C>
1-8                                     $20 per route mile per month
-------------------------------------------------------------------------
9-12                                    $25 per route mile per month
-------------------------------------------------------------------------
13-24                                 $28.50 per route mile per month
-------------------------------------------------------------------------
25+                                     $30 per route mile per month
-------------------------------------------------------------------------
EACH CONDUIT EXCHANGED OR SOLD          $35 per route mile per month
-------------------------------------------------------------------------
</Table>

         39.3.C Adjustment of monthly per mile fees, fees to third parties and
         maximum labor charge maintenance fees to the Builder in Article 39.3A
         and B above will be made every two (2) years beginning with the second
         anniversary of the Link Acceptance Date, by the increase, if any, in
         the Consumer Price Index, All Urban Consumers (CPI-U), U.S. City
         Average, published by the United States Department of Labor, Bureau of
         Labor Statistics (1982-84=100) for the twelve (12) month period ending
         three months prior to such anniversary of the Link Acceptance Date. In
         the event the Bureau of Labor Statistics (or any successor
         organization) no longer publishes the CPI-U, AT&T may designate the
         statistical index it deems most appropriate for adjustments and, from
         the date the CPI-U ceased to be published, such index shall be used to
         make adjustments under

<Page>

         this provision. AT&T will confirm such increases to PFN in writing.

39.4     TERM. The fees and services for this maintenance will commence on a
         Link by Link basis following the Acceptance of each Link. Unless
         earlier terminated as set forth in this Agreement, this Article 39 and
         Exhibit C will be in force for the lesser of the period of time that
         the AT&T System is in use on a reasonably continuous basis for
         telecommunications purposes or the Builder System is in use for the
         same purposes.

11.      MODIFICATIONS TO EXHIBITS:

         A.       Exhibit B is deleted in its entirety and replaced with the
         modified Exhibit B attached hereto.

         B.       Exhibit C: is hereby deleted in its entirety and replaced with
         the modified and renamed Exhibit C: Maintenance Procedures attached
         hereto.

         C.       Exhibit G: "Fiber and Conduit Disposition Agreement" is hereby
         deleted from this Agreement in its entirety. It is the intent of the
         parties that by the deletion of Exhibit G that neither party shall have
         any fiber and conduit disposition obligations.

         D.       Exhibit O is deleted in its entirety and replaced with the
         modified Exhibit O.

         E.       Exhibit P: General Terms and Conditions Associated with Land
         Rights of OA Buildings and Services Contract is deleted in its entirety
         and is replaced with the modified Exhibit P attached hereto.

         F.       Exhibit Q: E-Commerce Terms and Conditions are added to this
         Agreement and attached hereto.

<Page>

This Amendment No. 5 is effective as of the execution of this Amendment by both
parties and shall be incorporated in and shall constitute a part of the
Agreement as if fully set forth therein. EXCEPT AS AMENDED HEREIN, ALL TERMS AND
CONDITIONS OF THE AGREEMENT REMAIN UNCHANGED.



APPROVAL:

ACKNOWLEDGED AND AGREED TO BY:


PF.NET CORP.                                 AT&T CORP.

BY   /S/ DONALD L. BRANSCOME                 BY   /S/ DIANA L. JONES
     ------------------------------               ------------------------------
     (signature)                                  (signature)

NAME DONALD L. BRANSCOME                     NAME DIANA L. JONES

     ------------------------------               ------------------------------

TITLE     SENIOR VICE PRESIDENT -            TITLE     PROCUREMENT DIRECTOR,
          BUSINESS DEVELOPMENT                         AT&T SUPPLIER MANAGEMENT
     ------------------------------               ------------------------------



DATE                                         DATE
     ------------------------------               ------------------------------
     (typed or printed)                           (typed or printed)