Exhibit 10.20

AMENDMENT OF LEASE

This agreement
(Agreement), made as of this 11thday of January, 2007 (but expressly deemed effective as of the
1stday of May, 2006), between 60 HUDSON OWNER LLC(successor to Westport Communications LLC and Hudson
Telegraph Associates, L.P., formerly known as Hudson Telegraph Associates), a Delaware limited liability company, having an address c/o Williams Real Estate Co. Inc., 380 Madison Avenue, New York, New York 10017-2513 (Landlord) and
FIBERNET EQUAL ACCESS, LLC, a New York limited liability company, having an address at 570 Lexington Avenue, New York, New York 10022 (Tenant).

W I T N E S S E T H:

WHEREAS, Landlord and Tenant are the present parties to an
agreement of lease dated as of April 1, 2001 (Original Lease), as thereafter amended on numerous occasions (collectively, Existing Lease), pursuant to which Landlord now leases to Tenant and Tenant now leases from
Landlord portions of the ground floor and basement (collectively, Demised Premises), as more particularly described in the Existing Lease, in Landlords building known as 60 Hudson Street, New York, New York; and

WHEREAS, Landlord and Tenant wish to amend the Existing Lease as set forth herein.

NOW, THEREFORE, in consideration of the foregoing and the mutual covenants hereinafter contained, Landlord and Tenant agree that the Existing
Lease is hereby further amended as follows:

1. All terms contained in this Agreement shall, for the purposes hereof, have the same meanings
ascribed to them in the Existing Lease unless otherwise defined herein. As used herein, the term Lease shall mean the Existing Lease, as amended by this Agreement and as the same may be hereafter amended.

2. (A) Pursuant to an amendment of the Original Lease, dated November 7, 2002 (Condenser Water Amendment), Tenant has installed water
cooled supplementary air conditioning equipment in the Demised Premises having an air conditioning capacity of ninety (90) tons (Supplemental System) and Landlord is furnishing the condenser water necessary to operate the
Supplemental System. Tenant is presently paying Landlord an annual Condenser Water Charge for the Supplemental System of $99,342.90 per annum, which Condenser Water Charge is subject to adjustment as provided in the Condenser Water Amendment.

(B) As of May 1, 2006, Tenant installed additional water cooled supplementary air conditioning equipment having a further air
conditioning capacity of an additional ninety (90) tons (Additional Supplemental System), for which Landlord also is furnishing the necessary condenser water. Effective as of May 1, 2006, Tenant shall pay Landlord an additional
Condenser Water Charge for the Additional Supplemental System initially at the rate of $99,342.90 per annum. Such initial Condenser Water Charge shall be subject to adjustment and payment in accordance with Paragraph 2(B) of the Condenser Water
Amendment.

(C) The provisions of Paragraph 2(C) of the Condenser Water Amendment also shall be applicable to the Additional Supplemental
System.



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3. Tenant covenants, represents and warrants that Tenant has had no dealings or communications with any
broker or agent in connection with the consummation of this Agreement other than Williams Real Estate Co. Inc. (the Broker) and Tenant covenants and agrees to indemnify Landlord from and against all costs, expenses (including reasonable
attorneys fees and disbursements) and liability for any commission or other compensation claimed by any broker or agent (other than the Broker) with respect to this Agreement. Landlord shall pay any commission owing to the Broker in connection
with this Agreement. The provisions of this Paragraph shall survive any termination of this Agreement.

4. This Agreement may not be
changed orally, but only by a writing signed by the party against whom enforcement thereof is sought.

5. The submission of this Agreement
to Tenant shall not constitute an offer by Landlord to execute and exchange this Agreement with Tenant and is made subject to Landlords acceptance, execution and delivery thereof.

IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of the day and year first above written.



|                                                                                                                                                           |  |  |  |                              |  |                                                        |  |                                              |  | 
|---------------------------------------------------------------------------------------------------------------------------------------------------------- |  |  |  | ---------------------------- |  | ------------------------------------------------------ |  | -------------------------------------------- |  | 
|                                                                                                                                                           |  |  |  | 60 HUDSON OWNER LLC         
|                                                                                                                                                           |  |  | 
|                                                                                                                                                           |  |  |  | By:                          |  | HUDSON TELEGRAPH ASSOCIATES, L.P., its managing member
|                                                                                                                                                           |  |  |  |                             
|                                                                                                                                                           |  |  |  |                              |  | By:                                                    |  | Sixty Hudson Management LLC, general
partner
|                                                                                                                                                           |  |  |  |                              | 
|                                                                                                                                                           |  |  |  |                              |  |                                                        |  | By:                                          |  | 
|                                                                                                                                                           |  |  |  |                              |  |                                                        |  | Name:                                        |  | 
|                                                                                                                                                           |  |  |  |                              |  |                                                        |  | Manager                                      |  | 
|                                                                                                                                                           |  | 
|                                                                                                                                                           |  |  |  | FIBERNET EQUAL ACCESS, LLC  
|                                                                                                                                                           |  |  | 
|                                                                                                                                                           |  |  |  | By:                          |  |                                                       
|                                                                                                                                                           |  |  |  | Name:                        |  |                                                       
|                                                                                                                                                           |  |  |  | Title:                       |  |                                                       
|                                                                                                                                                          
|By its execution below, the undersigned acknowledges its agreement to be bound by this Agreement and the Existing Lease jointly and severally with
Tenant.
|                                                                                                                                                           |  | 
|                                                                                                                                                           |  |  |  | FIBERNET TELECOM GROUP, INC.
|                                                                                                                                                           |  |  | 
|                                                                                                                                                           |  |  |  | By:                          |  |                                                       
|                                                                                                                                                           |  |  |  | Name:                        |  |                                                       
|                                                                                                                                                           |  |  |  | Title:                       |  |                                                       



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