Exhibit 5.1 [Letterhead of Jay J. Miller, Esq.] February 8, 2002 Board of Directors Covista Communications, Inc. 150 Clove Road Little Falls, New Jersey 07424 Re: Registration Statement on Form S-8 Gentlemen: I am issuing this opinion in connection with a Registration Statement on Form S-8 (the "Registration Statement") being filed on the date hereof with the Securities and Exchange Commission (the "SEC") under the Securities Act of 1933, as amended (the "Act") relating to 900,000 shares (the "Shares") of Common Stock, par value $.05 per share, of Covista Communications, Inc., a New Jersey corporation (the "Company"), which are issuable pursuant to the Company's 2001 Equity Incentive Plan (the "Plan"). In connection with this opinion, I have examined such documents as I have considered relevant, including the Plan; the Company's Certificate of Incorporation, as amended; the Company's By-Laws; minutes of the Company's corporate proceedings; an executed copy of the Registration Statement and all documents incorporated by reference therein and exhibits thereto, in the form filed or to be filed with the SEC; and such matters of law which I have deemed necessary in order to deliver this opinion. In the course of such examination, I have assumed the genuineness of all signatures, the authority of all signatories to sign on behalf of the principals, if any, the authenticity of all documents submitted to me as original documents and the conformity to original documents of all documents submitted to me as certified or photostatic copies. As to certain factual matters, I have relied upon information furnished to me by officers of the Company. Based on the foregoing and solely in reliance thereof, it is my opinion that the Shares have been duly authorized and, when issued and paid for as contemplated by the Plan, will be validly issued, fully paid and nonassessable. I hereby consent to the filing of this letter as an exhibit to the Registration Statement, and to all references to this opinion included in the Registration Statement. In giving such consent, I do not admit that I am in the category of persons whose consent is required under Section 7 of the Act or the Rules and Regulations of the SEC promulgated thereunder. Very truly yours, /s/ Jay J. Miller Jay J. Miller