Exhibit 10.15



Portions of this exhibit have been omitted and filed separately pursuant to an application for confidential treatment filed with the
Securities and Exchange Commission pursuant to Rule 24b-2 under the Securities Exchange Act of 1934, as amended.



Omissions are designated as [***].



EIGHTH AMENDMENT TO COST SHARING AND IRU

AGREEMENT



THIS EIGHTH AMENDMENT TO COST SHARING AND IRU AGREEMENT (this Seventh Amendment)
is made and entered into as of the 23 day of March, 2002, by and between LEVEL 3 COMMUNICATIONS, LLC, a Delaware limited liability company, (Grantor) and CABLE & WIREI FSS USA, INC., a District of Columbia corporation,
(Grantee).



RECITALS



A. Grantor and Grantee entered into that certain Cost Sharing and IRU
Agreement dated May 25, 1999, as amended by First Amendment to Cost Sharing and IRU Agreement dated August 11, 2000, Second Amendment to Cost Sharing and IRU Agreement dated August 11, 2000, Third Amendment to Cost Sharing and IRU Agreement dated
November 22, 2000, Fourth Amendment to Cost Sharing and IRU Agreement dated March 14, 2001, Fifth Amendment to Cost Sharing and IRU Agreement dated February 15, 2001, Sixth Amendment to Cost Sharing and IRU Agreement dated August 7, 2001, and
Seventh Amendment Cost Sharing and IRU Agreement dated March 6, 2002 (collectively, the Agreement).



B. Grantee desires to obtain an IRU in additional fibers within the building located at [***] where the Grantor System is located and connecting
Grantees facilities to Grantor System.



C. Grantor
desires to convey to Grantee an IRU in certain additional fibers located at [***] as further specified herein, subject to and in accordance with the terms and conditions of the Agreement applicable to Metropolitan Fibers, except for IRU Term and as
otherwise set forth in this Amendment.



In consideration of
good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged, Grantor and Grantee hereby agree as follows:



ARTICLE 1

NEW RISER SEGMENT



2.01    Grantor shall construct the Riser Segment identified in
Exhibit A and grant to Grantee an exclusive IRU in the number of fibers identified in Exhibit A in accordance with the terms and conditions of the Agreement applicable to Metropolitan Fibers, except for the IRU Term and as
otherwise set forth in this Amendment. The Term of the IRU in the Grantee Fibers within the Riser Segment identified in Exhibit A shall be five (5) years from the Acceptance Date.



2.02    Grantee shall pay to Grantor an initial IRU Contribution in the
amount of $[***] for the Riser Segment identified in Exhibit A. The initial IRU Contribution for such Riser Segment shall be due and payable within five (5) days after the execution of this Amendment.



2.03    Grantee shall pay a remaining IRU Contribution in the amount of
$[***] for the Riser Segment identified in Exhibit A. Upon the Acceptance Date for such Riser Segment, Grantor will send Grantee an invoice for payment of the remaining IRU Contribution and Grantee shall pay such invoiced amount within
thirty (30) days after receipt of such invoice.





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ARTICLE 3

MISCELLANEOUS



3.01    The Recitals are incorporated into this Eighth Amendment by this reference. Capitalized terms used but not defined in this Eighth Amendment shall have the respective meanings ascribed to them in the Agreement.



3.02    Except as amended by this Eighth Amendment, the
original terms and conditions of the Agreement, as amended, shall continue in full force and effect and the Agreement, as amended, is hereby ratified and confirmed.



3.03    This Eighth Amendment may be executed in counterparts, each of which shall be deemed an original but together
which shall constitute but one and the same instrument.



IN WITNESS WHEREOF,
Grantor and Grantee have executed this Eighth Amendment as of the date first above written.



LEVEL 3 COMMUNICATIONS, LLC, a Delaware
limited liability companyBy:Title:

Sr. VP  GISDate:

March 23, 2002CABLE & WIRELESS USA, INC., a District of Columbia corporationBy:Title:

SVP NetworkDate:

March 14, 2002




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EXHIBIT A



1. Riser Segment Description



|         |  |             |  |                           |  |                                                    |  |                                     |  |                        
|-------- |  | ----------- |  | ------------------------- |  | -------------------------------------------------- |  | ----------------------------------- |  | -----------------------
|Location |  | Fiber Count |  | Type (On-Net or Off- Net) |  | Diverse or Non- Diverse to Riser Segment End Point |  | Riser Segment Interconnection Point |  | Riser Segment End Point
|[***]    |  | [***]       |  | On-Net                    |  | Non- Diverse                                       |  | [***]                               |  | [***]                  



2. IRU Contribution



|         |  |                          |  |                            |  |                            
|-------- |  | ------------------------ |  | -------------------------- |  | ---------------------------
|Location |  | Initial IRU Contribution |  | Remaining IRU Contribution |  | Total Fixed Cost to Grantee
|[***]    |  | [***]                    |  | [***]                      |  | [***]                      



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