X0303 4 2009-05-28 0 0000877931 Vertical Communications, Inc. VRCC 0001044321 MARXE AUSTIN W & GREENHOUSE DAVID M C/O SPECIAL SITUATIONS FUNDS 527 MADISON AVENUE, SUITE 2600 NEW YORK NY 10022 0 0 1 0 Common Stock 2009-05-28 4 S 0 1283016 0.01 D 5890826 I By Limited Partnerships This is a joint filing by Austin W. Marxe (Marxe) & David M. Greenhouse (Greenhouse). They share voting & investment control over all securities owned by Special Situations Fund III QP, L.P. (SSFQP), Special Situations Cayman Fund, L.P. (Cay), Special Situations Private Equity Fund, LP (PE), Special Situations Technology Fund, L.P. (Tech) & Special Situations Technology II, L.P. (Tech II), respectively. 3,775,515 shares of Common Stock are owned by SSFQP, 1,314,198 shares of Common Stock are owned by Cay, 0 shares of Common Stock are owned by PE, 123,282 shares of Common Stock are owned by Tech and 677,831 shares of Common Stock are owned by Tech II. The interest of Marxe & Greenhouse in the shares of Common Stock owned by SSFQP, Cay, PE, Tech, & Tech II is limited to the extent of his pecuniary interest. Austin W. Marxe 2009-06-01 David M. Greenhouse 2009-06-01