Digital Realty Trust (DLR)

RECITALS

A. Pursuant to that certain Securities Purchase Agreement (the “SNS Purchase Agreement”) dated as of the date hereof by and between Purchaser and Digital Services Phoenix, LLC, a Delaware limited liability company (collectively, the “SNS Purchaser”), on the one hand, and Sterling Telecom Holdings, LLC, a Delaware limited liability company (“STH”), George D. Slessman, an individual (“G. Slessman”), William D. Slessman, an individual (“W. Slessman”) and Anthony L. Wanger, an individual (“Wanger”, together with STH, G. Slessman and W. Slessman, collectively, the “SNS Sellers”), on the other hand, Purchaser is acquiring all of the outstanding equity interests in Sterling Network Services, LLC, a Delaware limited liability company (“SNS”) from the SNS Sellers.

B. Seller is the owner of the Property (as such term is hereinafter defined).

C. On the condition that the transactions contemplated under the SNS Purchase Agreement shall close immediately preceding or concurrently with the closing of the transaction contemplated hereunder (and the parties hereto agree that the transactions under each of the SNS Purchase Agreement and this Agreement will be closed by way of and in accordance with the Closing Escrow Agreement (defined below)), Seller desires to sell the Property to Purchaser, and Purchaser desires to purchase the Property from Seller, upon and subject to the terms and conditions of this Agreement.

THEREFORE, in consideration of the terms and conditions contained in this Agreement and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, Seller and Purchaser agree as follows:

RECITALS

WHEREAS, Consultant currently serves as the Executive Vice President, Technology Infrastructure for the Company pursuant to the terms of that certain employment letter agreement, dated July 31, 2004 between Consultant and the Company (the “Employment Agreement”);

WHEREAS, Consultant has been granted an option (the “Option”) to purchase 50,000 shares of Common Stock of the Company pursuant to the terms of that certain Option Agreement, dated December 16, 2004 between the Company and Consultant (the “Option Agreement”); and

WHEREAS, the Consultant and the Company have agreed that Consultant will terminate his employment with the Company but continue to serve as an unpaid consultant to the Company, as further set forth below.